Initial

.env.dist

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+APP_ENV=development
+APP_NAME=learning
+
+POSTGRES_DB=forum
+POSTGRES_USER=
+POSTGRES_PASSWORD=
+POSTGRES_HOST=postgres
+POSTGRES_PORT=5432
+
+ADMIN_NAME=
+ADMIN_PASSWORD=

.gitignore

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+vendor
+storage/postgres-data
+.env
+docker-compose.yml

app/Access/Controllers/AssignCategoryController.php

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+<?php
+
+declare(strict_types=1);
+
+namespace App\Access\Controllers;
+
+use App\Access\Models\AccessChecker\Access\AccessChecker;
+use App\Access\Models\AccessChecker\Forum\ModerateCategory\ModerateCategory;
+use App\Access\Models\Forbidden;
+use App\Auth\Models\Auth;
+use App\Forum\Category\Models\CategoryWriteRepository;
+use App\SharedKernel\Http\Validation;
+use App\User\Models\UserRepository;
+
+final class AssignCategoryController extends \Phalcon\Mvc\Controller
+{
+    public function mainAction(string $userId): void
+    {
+        if (!$this->getAccessChecker()->canManageAccesses()) {
+            throw new Forbidden();
+        }
+
+        $user = $this->getUserRepository()->get($userId);
+
+        if ($this->request->isPost()) {
+            $validation = new Validation([
+                'category_id' => 'required',
+            ]);
+            $validation->validate($_POST);
+
+            ModerateCategory::add($_POST['category_id'], $userId);
+
+            $this->response->redirect('/access/users/' . $userId . '/moderate-categories');
+            return;
+        }
+
+        echo $this->view->render(
+            __DIR__ . '/../Views/assign-category',
+            [
+                'user1' => $user,
+                'categories' => $this->getCategoryRepository()->findAll(),
+            ]
+        );
+    }
+
+    private function getCategoryRepository(): CategoryWriteRepository
+    {
+        return new CategoryWriteRepository();
+    }
+
+    private function getUserRepository(): UserRepository
+    {
+        return new UserRepository();
+    }
+
+    private function getAccessChecker(): AccessChecker
+    {
+        return new AccessChecker();
+    }
+
+    private function getAuth(): Auth
+    {
+        return new Auth();
+    }
+}

app/Access/Controllers/AssignRoleController.php

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+<?php
+
+declare(strict_types=1);
+
+namespace App\Access\Controllers;
+
+use App\Access\Models\AccessChecker\Access\AccessChecker;
+use App\Access\Models\Forbidden;
+use App\Access\Models\Role;
+use App\Auth\Models\Auth;
+use App\SharedKernel\Http\Validation;
+use App\User\Models\UserRepository;
+
+final class AssignRoleController extends \Phalcon\Mvc\Controller
+{
+    public function mainAction(string $userId): void
+    {
+        if (!$this->getAccessChecker()->canManageAccesses()) {
+            throw new Forbidden();
+        }
+
+        $user = $this->getUserRepository()->get($userId);
+
+        if ($this->request->isPost()) {
+            $validation = new Validation([
+                'role' => 'required',
+            ]);
+            $validation->validate($_POST);
+
+            $initiator = $this->getAuth()->getUserFromSession();
+
+            $user->assignRole(Role::fromValue($_POST['role']), $initiator->id);
+
+            $this->response->redirect('/users/' . $userId);
+            return;
+        }
+
+        echo $this->view->render(
+            __DIR__ . '/../Views/assign-role',
+            ['user1' => $user]
+        );
+    }
+
+    private function getUserRepository(): UserRepository
+    {
+        return new UserRepository();
+    }
+
+    private function getAccessChecker(): AccessChecker
+    {
+        return new AccessChecker();
+    }
+
+    private function getAuth(): Auth
+    {
+        return new Auth();
+    }
+}

app/Access/Controllers/DeleteModerateCategoryController.php

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+<?php
+
+declare(strict_types=1);
+
+namespace App\Access\Controllers;
+
+use App\Access\Models\AccessChecker\Access\AccessChecker;
+use App\Access\Models\AccessChecker\Forum\ModerateCategory\ModerateCategoryRepository;
+use App\Access\Models\Forbidden;
+use App\Auth\Models\Auth;
+use App\User\Models\UserRepository;
+
+final class DeleteModerateCategoryController extends \Phalcon\Mvc\Controller
+{
+    public function mainAction(string $userId, string $categoryId): void
+    {
+        if (!$this->getAccessChecker()->canManageAccesses()) {
+            throw new Forbidden();
+        }
+
+        $moderateCategory = $this->getModerateCategoryRepository()->getByUserIdAndCategoryId($userId, $categoryId);
+        $moderateCategory->delete();
+
+        $this->response->redirect('/access/users/' . $userId . '/moderate-categories');
+    }
+
+    private function getModerateCategoryRepository(): ModerateCategoryRepository
+    {
+        return new ModerateCategoryRepository();
+    }
+
+    private function getUserRepository(): UserRepository
+    {
+        return new UserRepository();
+    }
+
+    private function getAccessChecker(): AccessChecker
+    {
+        return new AccessChecker();
+    }
+}

app/Access/Controllers/ModerateCategoriesController.php

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+<?php
+
+declare(strict_types=1);
+
+namespace App\Access\Controllers;
+
+use App\Access\Models\AccessChecker\Access\AccessChecker;
+use App\Access\Models\AccessChecker\Forum\ModerateCategory\ModerateCategoryRepository;
+use App\Access\Models\Forbidden;
+use App\Auth\Models\Auth;
+use App\Forum\Category\Models\CategoryWriteRepository;
+use App\SharedKernel\Http\Validation;
+use App\User\Models\UserRepository;
+
+final class ModerateCategoriesController extends \Phalcon\Mvc\Controller
+{
+    public function mainAction(string $userId): void
+    {
+        if (!$this->getAccessChecker()->canManageAccesses()) {
+            throw new Forbidden();
+        }
+
+        $user = $this->getUserRepository()->get($userId);
+
+        echo $this->view->render(
+            __DIR__ . '/../Views/moderate-categories',
+            [
+                'user1' => $user,
+                'categories' => $this->getModerateCategoryRepository()->findByUserId($userId),
+            ]
+        );
+    }
+
+    private function getModerateCategoryRepository(): ModerateCategoryRepository
+    {
+        return new ModerateCategoryRepository();
+    }
+
+    private function getUserRepository(): UserRepository
+    {
+        return new UserRepository();
+    }
+
+    private function getAccessChecker(): AccessChecker
+    {
+        return new AccessChecker();
+    }
+}

app/Access/Models/AccessChecker/Access/AccessChecker.php

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+<?php
+
+declare(strict_types=1);
+
+namespace App\Access\Models\AccessChecker\Access;
+
+use App\Access\Models\Role;
+use App\Auth\Models\Auth;
+
+final class AccessChecker
+{
+    private $auth;
+
+    public function __construct()
+    {
+        $this->auth = new Auth();
+    }
+
+    public function canManageAccesses(): bool
+    {
+        $user = $this->auth->getUserFromSession();
+
+        if ($user === null) {
+            return false;
+        }
+
+        return $user->role == Role::admin()->value;
+    }
+}

app/Access/Models/AccessChecker/Forum/CategoryAccessChecker.php

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+<?php
+
+declare(strict_types=1);
+
+namespace App\Access\Models\AccessChecker\Forum;
+
+use App\Access\Models\Role;
+use App\Access\Models\AccessChecker\Forum\ModerateCategory\SessionStorage\CategoryIdsGetter;
+use App\Auth\Models\Auth;
+use Ramsey\Uuid\UuidInterface;
+
+final class CategoryAccessChecker
+{
+    private $auth;
+    private $categoryIdsGetter;
+
+    public function __construct()
+    {
+        $this->auth = new Auth();
+        $this->categoryIdsGetter = new CategoryIdsGetter();
+    }
+
+    public function canAdd(): bool
+    {
+        $user = $this->auth->getUserFromSession();
+
+        if ($user === null) {
+            return false;
+        }
+
+        if ($user->role === Role::admin()->value) {
+            return true;
+        }
+
+        return false;
+    }
+
+    public function canDelete(): bool
+    {
+        $user = $this->auth->getUserFromSession();
+
+        if ($user === null) {
+            return false;
+        }
+
+        if ($user->role === Role::admin()->value) {
+            return true;
+        }
+
+        return false;
+    }
+
+    public function canChange($categoryId): bool
+    {
+        $user = $this->auth->getUserFromSession();
+
+        if ($user === null) {
+            return false;
+        }
+
+        if ($user->role === Role::admin()->value) {
+            return true;
+        }
+
+        if ($user->role === Role::moderator()->value) {
+            return in_array($categoryId, $this->categoryIdsGetter->exec());
+        }
+
+        return false;
+    }
+}

app/Access/Models/AccessChecker/Forum/CommentAccessChecker.php

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+<?php
+
+declare(strict_types=1);
+
+namespace App\Access\Models\AccessChecker\Forum;
+
+use App\Access\Models\Role;
+use App\Access\Models\AccessChecker\Forum\ModerateCategory\SessionStorage\CategoryIdsGetter;
+use App\Auth\Models\Auth;
+use Ramsey\Uuid\UuidInterface;
+
+final class CommentAccessChecker
+{
+    private $auth;
+    private $categoryIdsGetter;
+
+    public function __construct()
+    {
+        $this->auth = new Auth();
+        $this->categoryIdsGetter = new CategoryIdsGetter();
+    }
+
+    public function canAdd(): bool
+    {
+        return true;
+    }
+
+    public function canDelete($categoryId, $authorId): bool
+    {
+        $user = $this->auth->getUserFromSession();
+
+        if ($user === null) {
+            return false;
+        }
+
+        if ($authorId === $user->id) {
+            return true;
+        }
+
+        if ($user->role === Role::admin()->value) {
+            return true;
+        }
+
+        if ($user->role === Role::moderator()->value) {
+            return in_array($categoryId, $this->categoryIdsGetter->exec());
+        }
+
+        return false;
+    }
+
+    public function canChange($categoryId, $authorId): bool
+    {
+        $user = $this->auth->getUserFromSession();
+
+        if ($user === null) {
+            return false;
+        }
+
+        if ($authorId === $user->id) {
+            return true;
+        }
+
+        if ($user->role === Role::admin()->value) {
+            return true;
+        }
+
+        if ($user->role === Role::moderator()->value) {
+            return in_array($categoryId, $this->categoryIdsGetter->exec());
+        }
+
+        return false;
+    }
+}

app/Access/Models/AccessChecker/Forum/ModerateCategory/ModerateCategory.php

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+<?php
+
+declare(strict_types=1);
+
+namespace App\Access\Models\AccessChecker\Forum\ModerateCategory;
+
+use App\Forum\Category\Models\Category;
+use App\Forum\Category\Models\CategoryWriteRepository;
+
+final class ModerateCategory extends \Phalcon\Mvc\Model
+{
+    public function initialize(): void
+    {
+        $this->setSource('access_forum_moderate_categories');
+    }
+
+    public static function add($categoryId, $userId): void
+    {
+        $moderateCategory = new self([
+            'user_id' => $userId,
+            'category_id' => $categoryId,
+        ]);
+
+        $moderateCategory->save();
+    }
+
+    public function getCategory(): Category
+    {
+        return (new CategoryWriteRepository())->get($this->category_id);
+    }
+}

app/Access/Models/AccessChecker/Forum/ModerateCategory/ModerateCategoryRepository.php

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+<?php
+
+declare(strict_types=1);
+
+namespace App\Access\Models\AccessChecker\Forum\ModerateCategory;
+
+use Phalcon\Mvc\Model\Resultset;
+
+final class ModerateCategoryRepository
+{
+    public function findByUserId($userId): Resultset
+    {
+        return ModerateCategory::find("user_id = '$userId'");
+    }
+
+    public function getByUserIdAndCategoryId($userId, $categoryId): ModerateCategory
+    {
+        return ModerateCategory::findFirst("user_id = '$userId' and category_id = '$categoryId'");
+    }
+}

app/Access/Models/AccessChecker/Forum/ModerateCategory/SessionStorage/CategoryIdsDestroyer.php

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+<?php
+
+declare(strict_types=1);
+
+namespace App\Access\Models\AccessChecker\Forum\ModerateCategory\SessionStorage;
+
+final class CategoryIdsDestroyer
+{
+    public function exec(): void
+    {
+        $this->getSession()->destroy('moderate_categories');
+    }
+
+    private function getSession()
+    {
+        return \Phalcon\DI::getDefault()->getShared('session');
+    }
+}

app/Access/Models/AccessChecker/Forum/ModerateCategory/SessionStorage/CategoryIdsGetter.php

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+<?php
+
+declare(strict_types=1);
+
+namespace App\Access\Models\AccessChecker\Forum\ModerateCategory\SessionStorage;
+
+final class CategoryIdsGetter
+{
+    public function exec(): array
+    {
+        return $this->getSession()->get('moderate_categories', []);
+    }
+
+    private function getSession()
+    {
+        return \Phalcon\DI::getDefault()->getShared('session');
+    }
+}

app/Access/Models/AccessChecker/Forum/ModerateCategory/SessionStorage/CategoryIdsSetter.php

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+<?php
+
+declare(strict_types=1);
+
+namespace App\Access\Models\AccessChecker\Forum\ModerateCategory\SessionStorage;
+
+use App\Access\Models\AccessChecker\Forum\ModerateCategory\ModerateCategoryRepository;
+use Ramsey\Uuid\UuidInterface;
+
+final class CategoryIdsSetter
+{
+    private $moderateCategoryRepository;
+
+    public function __construct()
+    {
+        $this->moderateCategoryRepository = new ModerateCategoryRepository();
+    }
+
+    public function exec(UuidInterface $userId): void
+    {
+        $session = $this->getSession();
+        $session->set('moderate_categories', []);
+
+        $moderateCategories = $this->moderateCategoryRepository->findByUserId($userId);
+
+        foreach ($moderateCategories as $moderateCategory) {
+            $session->set(
+                'moderate_categories',
+                array_merge(
+                    $session->get('moderate_categories'),
+                    [$moderateCategory->category_id]
+                )
+            );
+        }
+    }
+
+    private function getSession()
+    {
+        return \Phalcon\DI::getDefault()->getShared('session');
+    }
+}

app/Access/Models/AccessChecker/Forum/TopicAccessChecker.php

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+<?php
+
+declare(strict_types=1);
+
+namespace App\Access\Models\AccessChecker\Forum;
+
+use App\Access\Models\Role;
+use App\Access\Models\AccessChecker\Forum\ModerateCategory\SessionStorage\CategoryIdsGetter;
+use App\Auth\Models\Auth;
+use Ramsey\Uuid\UuidInterface;
+
+final class TopicAccessChecker
+{
+    private $auth;
+    private $categoryIdsGetter;
+
+    public function __construct()
+    {
+        $this->auth = new Auth();
+        $this->categoryIdsGetter = new CategoryIdsGetter();
+    }
+
+    public function canAdd(): bool
+    {
+        $user = $this->auth->getUserFromSession();
+
+        if ($user === null) {
+            return false;
+        }
+
+        return true;
+    }
+
+    public function canDelete($categoryId, $authorId): bool
+    {
+        $user = $this->auth->getUserFromSession();
+
+        if ($user === null) {
+            return false;
+        }
+
+        if ($authorId === $user->id) {
+            return true;
+        }
+
+        if ($user->role === Role::admin()->value) {
+            return true;
+        }
+
+        if ($user->role === Role::moderator()->value) {
+            return in_array($categoryId, $this->categoryIdsGetter->exec());
+        }
+
+        return false;
+    }
+
+    public function canChange($categoryId, $authorId): bool
+    {
+        $user = $this->auth->getUserFromSession();
+
+        if ($user === null) {
+            return false;
+        }
+
+        if ($authorId === $user->id) {
+            return true;
+        }
+
+        if ($user->role === Role::admin()->value) {
+            return true;
+        }
+
+        if ($user->role === Role::moderator()->value) {
+            return in_array($categoryId, $this->categoryIdsGetter->exec());
+        }
+
+        return false;
+    }
+}

app/Access/Models/AccessChecker/User/AccessChecker.php

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+<?php
+
+declare(strict_types=1);
+
+namespace App\Access\Models\AccessChecker\User;
+
+use App\Access\Models\Role;
+use App\Auth\Models\Auth;
+
+final class AccessChecker
+{
+    private $auth;
+
+    public function __construct()
+    {
+        $this->auth = new Auth();
+    }
+
+    public function canManageUsers(): bool
+    {
+        $user = $this->auth->getUserFromSession();
+
+        if ($user === null) {
+            return false;
+        }
+
+        return $user->role === Role::admin()->value;
+    }
+}

app/Access/Models/Forbidden.php

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+<?php
+
+declare(strict_types=1);
+
+namespace App\Access\Models;
+
+final class Forbidden extends \Exception
+{
+
+}

app/Access/Models/Role.php

@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Access\Models;
+
+use App\SharedKernel\Structs\Enum;
+
+final class Role extends Enum
+{
+    public static function user(): self
+    {
+        return new self('user');
+    }
+
+    public static function moderator(): self
+    {
+        return new self('moderator');
+    }
+
+    public static function admin(): self
+    {
+        return new self('admin');
+    }
+}

app/Access/Views/assign-category.volt

@@ -0,0 +1,76 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <title>{{ appName }}</title>
+  <link rel="stylesheet" href="/assets/css/material-icons.css">
+  <link rel="stylesheet" href="/assets/css/shared.css">
+  <link rel="stylesheet" href="/assets/css/header.css">
+
+  <link rel="stylesheet" href="/assets/css/breadcrumbs.css">
+  <link rel="stylesheet" href="/assets/css/form.css">
+
+  <link rel="stylesheet" href="/assets/css/pages/assign-category.css">
+</head>
+<body>
+
+<header>
+  <div class="page-box header-main">
+    <div class="header-logo">
+      <img src="/assets/img/logo.svg">
+    </div>
+    {% if user is not null %}
+      <div class="username">
+        <span>{{ user.name }}</span>
+        <span class="material-icons-outlined">account_box</span>
+      </div>
+    {% endif %}
+  </div>
+
+  <div class="page-box header-menu">
+    <div>
+      <a class="margin-right-8 text-gray" href="/">Topics</a>
+      {% if userAccess.canManageUsers() %}
+        <span class="margin-right-8 text-primary">Users</span>
+      {% endif %}
+      {% if user is null %}
+        <a class="text-gray" href="/login">Login</a>
+      {% else %}
+        <a class="text-gray" href="/logout">Logout</a>
+      {% endif %}
+    </div>
+  </div>
+</header>
+
+<main>
+  <div class="page-box">
+    <h1 class="title">Assign category</h1>
+
+    <nav>
+      <ol class="breadcrumbs">
+        <li class="breadcrumbs-item">
+          <a href="/users">Users</a>
+        </li>
+        <li class="breadcrumbs-item">
+          <a href="/users/{{ user1.id }}">{{ user1.name }}</a>
+        </li>
+        <li class="breadcrumbs-item">
+          <a href="/access/users/{{ user1.id }}/moderate-categories">Moderate categories</a>
+        </li>
+        <li class="breadcrumbs-item active">Assign category</li>
+      </ol>
+    </nav>
+
+    <form action="/access/users/{{ user1.id }}/assign-category" method="post">
+      <div>
+        <select name="category_id" class="form-input">
+          {% for category in categories %}
+            <option value="{{ category.id }}">{{ category.name }}</option>
+          {% endfor %}
+        </select>
+      </div>
+      <button type="submit" class="form-button">Assign</button>
+    </form>
+  </div>
+</main>
+</body>
+</html>

app/Access/Views/assign-role.volt

@@ -0,0 +1,73 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <title>{{ appName }}</title>
+  <link rel="stylesheet" href="/assets/css/material-icons.css">
+  <link rel="stylesheet" href="/assets/css/shared.css">
+  <link rel="stylesheet" href="/assets/css/header.css">
+
+  <link rel="stylesheet" href="/assets/css/breadcrumbs.css">
+  <link rel="stylesheet" href="/assets/css/form.css">
+
+  <link rel="stylesheet" href="/assets/css/pages/assign-role.css">
+</head>
+<body>
+
+<header>
+  <div class="page-box header-main">
+    <div class="header-logo">
+      <img src="/assets/img/logo.svg">
+    </div>
+    {% if user is not null %}
+      <div class="username">
+        <span>{{ user.name }}</span>
+        <span class="material-icons-outlined">account_box</span>
+      </div>
+    {% endif %}
+  </div>
+
+  <div class="page-box header-menu">
+    <div>
+      <a class="margin-right-8 text-gray" href="/">Topics</a>
+      {% if userAccess.canManageUsers() %}
+        <span class="margin-right-8 text-primary">Users</span>
+      {% endif %}
+      {% if user is null %}
+        <a class="text-gray" href="/login">Login</a>
+      {% else %}
+        <a class="text-gray" href="/logout">Logout</a>
+      {% endif %}
+    </div>
+  </div>
+</header>
+
+<main>
+  <div class="page-box">
+    <h1 class="title">Assign role</h1>
+
+    <nav>
+      <ol class="breadcrumbs">
+        <li class="breadcrumbs-item">
+          <a href="/users">Users</a>
+        </li>
+        <li class="breadcrumbs-item">
+          <a href="/users/{{ user1.id }}">{{ user1.name }}</a>
+        </li>
+        <li class="breadcrumbs-item active">Assign role</li>
+      </ol>
+    </nav>
+
+    <form action="/access/users/{{ user1.id }}/assign-role" method="post">
+      <div>
+        <select name="role" class="form-input">
+          <option value="user" {% if  user1.role == 'user' %} selected {% endif %}>User</option>
+          <option value="moderator" {% if  user1.role == 'moderator' %} selected {% endif %}>Moderator</option>
+          <option value="admin" {% if  user1.role == 'admin' %} selected {% endif %}>Admin</option>
+        </select>
+      </div>
+      <button type="submit" class="form-button">Assign role</button>
+    </form>
+  </div>
+</main>
+</body>
+</html>

app/Access/Views/moderate-categories.volt

@@ -0,0 +1,79 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <title>{{ appName }}</title>
+  <link rel="stylesheet" href="/assets/css/material-icons.css">
+  <link rel="stylesheet" href="/assets/css/shared.css">
+  <link rel="stylesheet" href="/assets/css/header.css">
+
+  <link rel="stylesheet" href="/assets/css/breadcrumbs.css">
+  <link rel="stylesheet" href="/assets/css/append-button.css">
+  <link rel="stylesheet" href="/assets/css/clickable-list.css">
+
+  <link rel="stylesheet" href="/assets/css/pages/moderate-categories.css">
+</head>
+<body>
+
+<header>
+  <div class="page-box header-main">
+    <div class="header-logo">
+      <img src="/assets/img/logo.svg">
+    </div>
+    {% if user is not null %}
+      <div class="username">
+        <span>{{ user.name }}</span>
+        <span class="material-icons-outlined">account_box</span>
+      </div>
+    {% endif %}
+  </div>
+
+  <div class="page-box header-menu">
+    <div>
+      <a class="margin-right-8 text-gray" href="/">Topics</a>
+      {% if userAccess.canManageUsers() %}
+        <span class="margin-right-8 text-primary">Users</span>
+      {% endif %}
+      {% if user is null %}
+        <a class="text-gray" href="/login">Login</a>
+      {% else %}
+        <a class="text-gray" href="/logout">Logout</a>
+      {% endif %}
+    </div>
+  </div>
+</header>
+
+<main>
+  <div class="page-box">
+    <h1 class="title">Moderate categories</h1>
+
+    <nav>
+      <ol class="breadcrumbs">
+        <li class="breadcrumbs-item">
+          <a href="/users">Users</a>
+        </li>
+        <li class="breadcrumbs-item">
+          <a href="/users/{{ user1.id }}">{{ user1.name }}</a>
+        </li>
+        <li class="breadcrumbs-item active">Moderate categories</li>
+      </ol>
+    </nav>
+
+    <a class="append-button margin-bottom-16" href="/access/users/{{ user1.id }}/assign-category">
+      <div>Assign category</div>
+      <span class="icon material-icons">add</span>
+    </a>
+
+    <div class="clickable-list">
+      {% for category in categories %}
+        <div class="clickable-list-item">
+          <div>
+            <div>{{ category.getCategory().name }}</div>
+          </div>
+          <a href="/access/users/{{ user1.id }}/moderate-categories/{{ category.category_id }}/delete" class="icon material-icons">delete</a>
+        </div>
+      {% endfor %}
+    </div>
+  </div>
+</main>
+</body>
+</html>

app/Access/routes.php

@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+return [
+    'access:moderate-categories' => [
+        'pattern' => '/access/users/{userId}/moderate-categories',
+        'paths' => [
+            'namespace' => 'App\Access\Controllers',
+            'controller' => 'moderate-categories',
+            'action' => 'main',
+        ],
+        'httpMethods' => ['GET', 'POST'],
+    ],
+    'access:delete-moderate-category' => [
+        'pattern' => '/access/users/{userId}/moderate-categories/{categoryId}/delete',
+        'paths' => [
+            'namespace' => 'App\Access\Controllers',
+            'controller' => 'delete-moderate-category',
+            'action' => 'main',
+        ],
+        'httpMethods' => ['GET'],
+    ],
+    'access:assign-category' => [
+        'pattern' => '/access/users/{userId}/assign-category',
+        'paths' => [
+            'namespace' => 'App\Access\Controllers',
+            'controller' => 'assign-category',
+            'action' => 'main',
+        ],
+        'httpMethods' => ['GET', 'POST'],
+    ],
+    'access:assign-role' => [
+        'pattern' => '/access/users/{userId}/assign-role',
+        'paths' => [
+            'namespace' => 'App\Access\Controllers',
+            'controller' => 'assign-role',
+            'action' => 'main',
+        ],
+        'httpMethods' => ['GET', 'POST'],
+    ],
+];

app/Auth/Controllers/LoginController.php

@@ -0,0 +1,44 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Auth\Controllers;
+
+use App\Auth\Models\Auth;
+use App\Auth\Models\LoginFailed;
+use App\SharedKernel\Controllers\ModuleViewRender;
+use App\SharedKernel\Controllers\Validation;
+
+final class LoginController extends \Phalcon\Mvc\Controller
+{
+    use ModuleViewRender;
+    use Validation;
+
+    public function execAction(): void
+    {
+        if ($this->request->isPost()) {
+            try {
+                $this->validatePostRequest([
+                    'name' => 'required',
+                    'password' => 'required'
+                ]);
+
+                $this->getAuth()->login($_POST['name'], $_POST['password']);
+                $this->response->redirect('/');
+
+                return;
+            } catch (\InvalidArgumentException|LoginFailed $exception) {
+                $this->renderView(['error' => $exception->getMessage()]);
+
+                return;
+            }
+        }
+
+        $this->renderView();
+    }
+
+    private function getAuth(): Auth
+    {
+        return new Auth();
+    }
+}

app/Auth/Controllers/LogoutController.php

@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Auth\Controllers;
+
+use App\Auth\Models\Auth;
+
+final class LogoutController extends \Phalcon\Mvc\Controller
+{
+    public function execAction(): void
+    {
+        $this->getAuth()->logout();
+
+        $this->response->redirect('/');
+    }
+
+    private function getAuth(): Auth
+    {
+        return new Auth();
+    }
+}

app/Auth/Models/Auth.php

@@ -0,0 +1,73 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Auth\Models;
+
+use App\Access\Models\AccessChecker\Forum\ModerateCategory\SessionStorage\CategoryIdsDestroyer;
+use App\Access\Models\AccessChecker\Forum\ModerateCategory\SessionStorage\CategoryIdsSetter;
+use App\User\Models\User;
+use App\User\Models\UserNotFound;
+use App\User\Models\UserRepository;
+use Ramsey\Uuid\Uuid;
+
+final class Auth
+{
+    private $userRepository;
+    private $accessSessionSetter;
+    private $accessSessionDestroyer;
+
+    public function __construct()
+    {
+        $this->userRepository = new UserRepository();
+        $this->accessSessionSetter = new CategoryIdsSetter();
+        $this->accessSessionDestroyer = new CategoryIdsDestroyer();
+    }
+
+    /**
+     * @return LoginFailed
+     */
+    public function login(string $name, string $password): void
+    {
+        try {
+            $user = $this->userRepository->getByName($name);
+        } catch (UserNotFound $exception) {
+            throw new LoginFailed();
+        }
+
+        if ($user->password_hash === hash('sha256', $password)) {
+            $this->getSession()->set('user_id', $user->id);
+            $this->accessSessionSetter->exec(Uuid::fromString($user->id));
+
+            return;
+        }
+
+        throw new LoginFailed();
+    }
+
+    public function getUserFromSession(): ?User
+    {
+        if (!$this->getSession()->has('user_id')) {
+            return null;
+        }
+
+        try {
+            $userId = Uuid::fromString($this->getSession()->get('user_id'));
+
+            return $this->userRepository->get($userId);
+        } catch (UserNotFound $exception) {
+            return null;
+        }
+    }
+
+    public function logout(): void
+    {
+        // $this->accessSessionDestroyer->exec();
+        $this->getSession()->destroy();
+    }
+
+    private function getSession()
+    {
+        return \Phalcon\DI::getDefault()->getShared('session');
+    }
+}

app/Auth/Models/IsNotAuthenticated.php

@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Auth\Models;
+
+final class IsNotAuthenticated extends \Exception
+{
+    public function __construct()
+    {
+        parent::__construct('Authentication required');
+    }
+}

app/Auth/Models/LoginFailed.php

@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Auth\Models;
+
+final class LoginFailed extends \Exception
+{
+    public function __construct()
+    {
+        parent::__construct('Username or password isn\'t correct');
+    }
+}

app/Auth/Views/login.volt

@@ -0,0 +1,66 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <title>{{ appName }}</title>
+  <link rel="stylesheet" href="/assets/css/material-icons.css">
+  <link rel="stylesheet" href="/assets/css/shared.css">
+  <link rel="stylesheet" href="/assets/css/header.css">
+
+  <link rel="stylesheet" href="/assets/css/form.css">
+
+  <link rel="stylesheet" href="/assets/css/pages/login.css">
+</head>
+<body>
+
+  <main class="full-height">
+    <div class="page-box content-centered min-height-380">
+
+      <div class="width-100 max-width-280 margin-bottom-8">
+        <div class="header-main">
+          <div class="header-logo">
+            <img src="/assets/img/logo.svg">
+          </div>
+          {% if user is not null %}
+            <div class="username">
+              <span>{{ user.name }}</span>
+              <span class="material-icons-outlined">account_box</span>
+            </div>
+          {% endif %}
+        </div>
+
+        <div class="header-menu">
+          <div>
+            <a class="margin-right-8 text-gray" href="/">Topics</a>
+            {% if userAccess.canManageUsers() %}
+              <a class="margin-right-8 text-gray" href="/users">USERS</a>
+            {% endif %}
+            <span class="text-primary" href="/login">LOGIN</span>
+          </div>
+        </div>
+      </div>
+
+      <h1 class="title width-100 max-width-280 margin-bottom-32">Login</h1>
+
+      {% if error is not null %}
+        <div class="error max-width-280" style="color: #000000;
+      width: 100%;
+      margin-top: -24px;height: auto;
+      margin-bottom: 8px;">
+          {{ error }}
+        </div>
+      {% endif %}
+
+      <form method="post" class="width-100 max-width-280">
+        <div>
+          <input class="form-input margin-bottom-16" name="name" placeholder="username" required />
+        </div>
+        <div>
+          <input class="form-input margin-bottom-16" name="password" type="password" placeholder="password" required />
+        </div>
+        <button class="form-button width-100" type="submit">Login</button>
+      </form>
+    </div>
+  </main>
+
+</body>
+</html>

app/Auth/routes.php

@@ -0,0 +1,24 @@
+<?php
+
+declare(strict_types=1);
+
+return [
+    'auth:login' => [
+        'pattern' => '/login',
+        'paths' => [
+            'namespace' => 'App\Auth\Controllers',
+            'controller' => 'login',
+            'action' => 'exec',
+        ],
+        'httpMethods' => ['GET', 'POST'],
+    ],
+    'auth:logout' => [
+        'pattern' => '/logout',
+        'paths' => [
+            'namespace' => 'App\Auth\Controllers',
+            'controller' => 'logout',
+            'action' => 'exec',
+        ],
+        'httpMethods' => ['GET'],
+    ],
+];

app/Forum/Category/Controllers/AddController.php

@@ -0,0 +1,60 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Category\Controllers;
+
+use App\Access\Models\AccessChecker\Forum\CategoryAccessChecker;
+use App\Access\Models\Forbidden;
+use App\Auth\Models\Auth;
+use App\Forum\Category\Models\Category;
+use App\SharedKernel\Controllers\ModuleViewRender;
+use App\SharedKernel\Controllers\Validation;
+use Ramsey\Uuid\Uuid;
+
+final class AddController extends \Phalcon\Mvc\Controller
+{
+    use ModuleViewRender;
+    use Validation;
+
+    public function mainAction()
+    {
+        if (!$this->getCategoryAccessChecker()->canAdd()) {
+            throw new Forbidden();
+        }
+
+        if ($this->request->isPost()) {
+            try {
+                $this->validatePostRequest(['name' => 'required|length_between:1,64']);
+
+                $user = $this->getAuth()->getUserFromSession();
+
+                $category = Category::add(
+                    Uuid::uuid4(),
+                    $_POST['name'],
+                    $user->id
+                );
+
+                $this->response->redirect('/' . $category->slug);
+
+                return;
+            } catch (\LogicException $e) {
+                $this->renderView(['error' => $e->getMessage(), 'name' => $_POST['name']]);
+
+                return;
+            }
+        }
+
+        $this->renderView();
+    }
+
+    private function getCategoryAccessChecker(): CategoryAccessChecker
+    {
+        return new CategoryAccessChecker();
+    }
+
+    private function getAuth(): Auth
+    {
+        return new Auth();
+    }
+}

app/Forum/Category/Controllers/DeleteController.php

@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Category\Controllers;
+
+use App\Access\Models\AccessChecker\Forum\CategoryAccessChecker;
+use App\Access\Models\Forbidden;
+use App\Forum\Category\Models\CategoryWriteRepository;
+use Ramsey\Uuid\Uuid;
+
+final class DeleteController extends \Phalcon\Mvc\Controller
+{
+    public function mainAction(string $id): void
+    {
+        if (!$this->getCategoryAccessChecker()->canDelete()) {
+            throw new Forbidden();
+        }
+
+        $category = $this->getCategoryRepository()->get(Uuid::fromString($id));
+        $category->delete();
+
+        $this->response->redirect('/');
+    }
+
+    private function getCategoryRepository(): CategoryWriteRepository
+    {
+        return new CategoryWriteRepository();
+    }
+
+    private function getCategoryAccessChecker(): CategoryAccessChecker
+    {
+        return new CategoryAccessChecker();
+    }
+}

app/Forum/Category/Controllers/EditController.php

@@ -0,0 +1,56 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Category\Controllers;
+
+use App\Access\Models\AccessChecker\Forum\CategoryAccessChecker;
+use App\Access\Models\Forbidden;
+use App\Auth\Models\Auth;
+use App\Forum\Category\Models\CategoryWriteRepository;
+use App\SharedKernel\Controllers\ModuleViewRender;
+use App\SharedKernel\Controllers\Validation;
+
+final class EditController extends \Phalcon\Mvc\Controller
+{
+    use ModuleViewRender;
+    use Validation;
+
+    public function mainAction(string $id)
+    {
+        if (!$this->getCategoryAccessChecker()->canChange($id)) {
+            throw new Forbidden();
+        }
+
+        $category = $this->getCategoryRepository()->get($id);
+
+        if ($this->request->isPost()) {
+            $this->validatePostRequest(['name' => 'required|length_between:1,64']);
+
+            $user = $this->getAuth()->getUserFromSession();
+
+            $category->edit($_POST['name'], $user->id);
+
+            $this->response->redirect('/' . $category->slug);
+
+            return;
+        }
+
+        $this->renderView(['category' => $category]);
+    }
+
+    private function getCategoryAccessChecker(): CategoryAccessChecker
+    {
+        return new CategoryAccessChecker();
+    }
+
+    private function getAuth(): Auth
+    {
+        return new Auth();
+    }
+
+    private function getCategoryRepository(): CategoryWriteRepository
+    {
+        return new CategoryWriteRepository();
+    }
+}

app/Forum/Category/Controllers/IndexController.php

@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Category\Controllers;
+
+use App\Forum\Category\Models\CategoryReadRepository;
+use App\Forum\Topic\Models\TopicReadRepository;
+use App\SharedKernel\Controllers\ModuleViewRender;
+
+final class IndexController extends \Phalcon\Mvc\Controller
+{
+    use ModuleViewRender;
+
+    public function mainAction(): void
+    {
+        $topicsPerCategory = 5;
+        $categories = $this->getCategoryReadRepository()->findNotEmptyOrderedByLastActivity();
+
+        foreach ($categories as &$category) {
+            $category['last_topics'] = $this
+                ->getTopicReadRepository()
+                ->findByCategoryIdOrderedByLastActivity($category['id'], $topicsPerCategory);
+        }
+
+        $this->renderView(['categories' => $categories, 'topicsPerCategory' => $topicsPerCategory]);
+    }
+
+    private function getCategoryReadRepository(): CategoryReadRepository
+    {
+        return new CategoryReadRepository();
+    }
+
+    private function getTopicReadRepository(): TopicReadRepository
+    {
+        return new TopicReadRepository();
+    }
+}

app/Forum/Category/Controllers/ShowController.php

@@ -0,0 +1,50 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Category\Controllers;
+
+use App\Forum\Category\Models\CategoryReadRepository;
+use App\Forum\Topic\Models\TopicReadRepository;
+use App\SharedKernel\Controllers\ModuleViewRender;
+use App\SharedKernel\Controllers\Pagination;
+
+final class ShowController extends \Phalcon\Mvc\Controller
+{
+    use ModuleViewRender;
+    use Pagination;
+
+    public function mainAction(string $slug): void
+    {
+        $rowsPerPage = 10;
+        $page = $this->getCurrentPage();
+
+        $category = $this->getCategoryReadRepository()->getBySlug($slug);
+
+        $topics = $this
+            ->getTopicReadRepository()
+            ->findByCategoryIdOrderedByLastActivity(
+                $category['id'],
+                $rowsPerPage,
+                $this->getSkipRowsNumber($rowsPerPage)
+            );
+        $topicsCount = $this->getTopicReadRepository()->countByCategoryId($category['id']);
+
+        $this->renderView([
+            'category' => $category,
+            'topics' => $topics,
+            'page' => $page,
+            'pages' => $this->getTotalPages($topicsCount, $rowsPerPage),
+        ]);
+    }
+
+    private function getCategoryReadRepository(): CategoryReadRepository
+    {
+        return new CategoryReadRepository();
+    }
+
+    private function getTopicReadRepository(): TopicReadRepository
+    {
+        return new TopicReadRepository();
+    }
+}

app/Forum/Category/Models/Category.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Category\Models;
+
+use App\Forum\Topic\Models\TopicWriteRepository;
+use Phalcon\Mvc\Model\Resultset;
+
+final class Category extends \Phalcon\Mvc\Model
+{
+    public function initialize(): void
+    {
+        $this->setSource('forum_categories');
+    }
+
+    public static function add($id, string $name, $userId): self
+    {
+        if ((new CategoryReadRepository())->existByName(ucfirst($name))) {
+            throw new CategoryAlreadyExist();
+        }
+
+        $category = new self([
+            'id' => $id,
+            'name' => ucfirst($name),
+            'slug' => UniqueSlugGenerator::generate($name),
+            'created_at' => (new \DateTime('now'))->format('Y-m-d H:i:s'),
+            'created_by' => $userId,
+        ]);
+
+        $category->save();
+
+        return $category;
+    }
+
+    public function edit(string $name, $userId): void
+    {
+        $this->name = ucfirst($name);
+        $this->slug = UniqueSlugGenerator::generate($name);
+        $this->updated_at = (new \DateTime('now'))->format('Y-m-d H:i:s');
+        $this->updated_by = $userId;
+
+        $this->save();
+    }
+
+    public function delete(): void
+    {
+        foreach ((new TopicWriteRepository())->findByCategoryId($this->id) as $topic) {
+            $topic->delete();
+        }
+
+        parent::delete();
+    }
+}

app/Forum/Category/Models/CategoryAlreadyExist.php

@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Category\Models;
+
+final class CategoryAlreadyExist extends \DomainException
+{
+    public function __construct()
+    {
+        parent::__construct('Category with same name already exist');
+    }
+}

app/Forum/Category/Models/CategoryNotFound.php

@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Category\Models;
+
+use App\SharedKernel\Exceptions\NotFoundException;
+
+final class CategoryNotFound extends NotFoundException
+{
+    public function __construct()
+    {
+        parent::__construct('Category not found');
+    }
+}

app/Forum/Category/Models/CategoryReadRepository.php

@@ -0,0 +1,74 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Category\Models;
+
+final class CategoryReadRepository
+{
+    public function existByName(string $name): bool
+    {
+        $connection = \Phalcon\DI::getDefault()->getShared('db');
+        $query = $connection->query("SELECT count(id) FROM forum_categories WHERE name = '$name'");
+
+        return 0 !== (int) $query->fetch()[0];
+    }
+
+    public function existBySlug(string $slug): bool
+    {
+        $connection = \Phalcon\DI::getDefault()->getShared('db');
+        $query = $connection->query("SELECT count(id) FROM forum_categories WHERE slug = '$slug'");
+
+        return 0 !== (int) $query->fetch()[0];
+    }
+
+    public function getBySlug(string $slug): array
+    {
+        $connection = \Phalcon\DI::getDefault()->getShared('db');
+
+        $sql = "SELECT id, name, slug FROM forum_categories WHERE slug = '$slug'";
+
+        $query = $connection->query($sql);
+        $query->setFetchMode(\Phalcon\Db::FETCH_ASSOC);
+
+        $result = $query->fetch();
+
+        if ($result === false) {
+            throw new CategoryNotFound();
+        }
+
+        return $result;
+    }
+
+    public function findNotEmptyOrderedByLastActivity(): array
+    {
+        $connection = \Phalcon\DI::getDefault()->getShared('db');
+
+        $sql = <<<SQL
+SELECT id, name, slug, topics_count.topics_count
+FROM forum_categories
+    LEFT JOIN (
+        SELECT category_id, max(created_at) as created_at
+        FROM forum_topics
+        GROUP BY 1
+    ) last_topic ON last_topic.category_id = forum_categories.id
+    LEFT JOIN (
+        SELECT ft.category_id, max(fc.created_at) as created_at
+        FROM forum_comments fc
+        INNER JOIN forum_topics ft ON ft.id = fc.topic_id
+        GROUP BY 1
+    ) last_comment ON last_comment.category_id = forum_categories.id
+    LEFT JOIN (
+        SELECT category_id, count(id) as topics_count
+        FROM forum_topics
+        GROUP BY 1 
+    ) topics_count ON topics_count.category_id = forum_categories.id
+ORDER BY last_topic.created_at DESC NULLS LAST, last_comment.created_at DESC NULLS LAST
+SQL;
+
+        $query = $connection->query($sql);
+        $query->setFetchMode(\Phalcon\Db::FETCH_ASSOC);
+
+        return $query->fetchAll();
+    }
+}

app/Forum/Category/Models/CategoryWriteRepository.php

@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Category\Models;
+
+use Phalcon\Mvc\Model\Resultset;
+
+final class CategoryWriteRepository
+{
+    public function get($id): Category
+    {
+        $category = Category::findFirst("id = '$id'");
+
+        if ($category === false) {
+            throw new CategoryNotFound();
+        }
+
+        return $category;
+    }
+
+    public function getBySlug(string $slug): Category
+    {
+        $category = Category::findFirst("slug = '$slug'");
+
+        if ($category === false) {
+            throw new CategoryNotFound();
+        }
+
+        return $category;
+    }
+
+    public function findAll(): Resultset
+    {
+        return Category::find();
+    }
+}

app/Forum/Category/Models/UniqueSlugGenerator.php

@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Category\Models;
+
+use App\SharedKernel\StringConverter;
+
+final class UniqueSlugGenerator
+{
+    public static function generate(string $name): string
+    {
+        $config = include __DIR__ . '/../config.php';
+        $categoryReadRepository = new CategoryReadRepository();
+        $number = 0;
+
+        while (true) {
+            $slug = StringConverter::readableToSlug($name) . ($number === 0 ? '' : '-' . $number);
+
+            if (!in_array($slug, $config['excluding_slugs']) && !$categoryReadRepository->existBySlug($slug)) {
+                return $slug;
+            }
+
+            $number++;
+        }
+    }
+}

app/Forum/Category/Views/add.volt

@@ -0,0 +1,78 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <title>{{ appName }}</title>
+  <link rel="stylesheet" href="/assets/css/material-icons.css">
+  <link rel="stylesheet" href="/assets/css/shared.css">
+  <link rel="stylesheet" href="/assets/css/header.css">
+
+  <link rel="stylesheet" href="/assets/css/breadcrumbs.css">
+  <link rel="stylesheet" href="/assets/css/form.css">
+
+  <link rel="stylesheet" href="/assets/css/pages/add-category.css">
+</head>
+<body>
+
+<header>
+  <div class="page-box header-main">
+    <div class="header-logo">
+      <img src="/assets/img/logo.svg">
+    </div>
+    {% if user is not null %}
+      <div class="username">
+        <span>{{ user.name }}</span>
+        <span class="material-icons-outlined">account_box</span>
+      </div>
+    {% endif %}
+  </div>
+
+  <div class="page-box header-menu">
+    <div>
+      <span class="margin-right-8 text-primary">Topics</span>
+      {% if userAccess.canManageUsers() %}
+        <a class="margin-right-8 text-gray" href="/users">Users</a>
+      {% endif %}
+      {% if user is null %}
+        <a class="text-gray" href="/login">Login</a>
+      {% else %}
+        <a class="text-gray" href="/logout">Logout</a>
+      {% endif %}
+    </div>
+  </div>
+</header>
+
+<main>
+  <div class="page-box">
+    <h1 class="title">Add category</h1>
+
+    <nav>
+      <ol class="breadcrumbs">
+        <li class="breadcrumbs-item">
+          <a href="/">All categories</a>
+        </li>
+        <li class="breadcrumbs-item active">New</li>
+      </ol>
+    </nav>
+
+    {% if error is not null %}
+      <div class="error margin-bottom-16" style="color: #000000;width: 100%;">
+        {{ error }}
+      </div>
+    {% endif %}
+
+    <form action="/add-category" method="post">
+      <div>
+        <input
+            class="form-input"
+            name="name"
+            placeholder="Name of the category"
+            {% if name is not null %} value="{{ name }}" {% endif %}
+            required
+        />
+      </div>
+      <button class="form-button" type="submit">Add category</button>
+    </form>
+  </div>
+</main>
+</body>
+</html>

app/Forum/Category/Views/edit.volt

@@ -0,0 +1,79 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <title>{{ appName }}</title>
+  <link rel="stylesheet" href="/assets/css/material-icons.css">
+  <link rel="stylesheet" href="/assets/css/shared.css">
+  <link rel="stylesheet" href="/assets/css/header.css">
+
+  <link rel="stylesheet" href="/assets/css/breadcrumbs.css">
+  <link rel="stylesheet" href="/assets/css/append-button.css">
+  <link rel="stylesheet" href="/assets/css/form.css">
+
+  <link rel="stylesheet" href="/assets/css/pages/add-category.css">
+</head>
+<body>
+
+<header>
+  <div class="page-box header-main">
+    <div class="header-logo">
+      <img src="/assets/img/logo.svg">
+    </div>
+    {% if user is not null %}
+      <div class="username">
+        <span>{{ user.name }}</span>
+        <span class="material-icons-outlined">account_box</span>
+      </div>
+    {% endif %}
+  </div>
+
+  <div class="page-box header-menu">
+    <div>
+      <span class="margin-right-8 text-primary">Topics</span>
+      {% if userAccess.canManageUsers() %}
+        <a class="margin-right-8 text-gray" href="/users">Users</a>
+      {% endif %}
+      {% if user is null %}
+        <a class="text-gray" href="/login">Login</a>
+      {% else %}
+        <a class="text-gray" href="/logout">Logout</a>
+      {% endif %}
+    </div>
+  </div>
+</header>
+
+<main>
+  <div class="page-box">
+    <h1 class="title">Edit category</h1>
+
+    <nav>
+      <ol class="breadcrumbs">
+        <li class="breadcrumbs-item">
+          <a href="/">All categories</a>
+        </li>
+        <li class="breadcrumbs-item">
+          <a href="/{{ category.slug }}">{{ category.name }}</a>
+        </li>
+        <li class="breadcrumbs-item active">Edit</li>
+      </ol>
+    </nav>
+
+    <form action="/categories/{{ category.id }}" method="post">
+      <div>
+        <input class="form-input" name="name" placeholder="Name of the category" value="{{ category.name }}" />
+      </div>
+      <div style="display: flex;justify-content: space-between;">
+        <button class="form-button" type="submit">Update</button>
+
+        {% if categoryAccess.canDelete() %}
+          <a class="form-button" href="/categories/{{ category.id }}/delete">
+            <span class="icon material-icons" style="margin-right: 4px">delete</span>
+            Delete category
+          </a>
+        {% endif %}
+      </div>
+    </form>
+  </div>
+</main>
+</body>
+</html>

app/Forum/Category/Views/index.volt

@@ -0,0 +1,98 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <title>{{ appName }}</title>
+  <link rel="stylesheet" href="/assets/css/material-icons.css">
+  <link rel="stylesheet" href="/assets/css/shared.css">
+  <link rel="stylesheet" href="/assets/css/header.css">
+
+  <link rel="stylesheet" href="/assets/css/breadcrumbs.css">
+  <link rel="stylesheet" href="/assets/css/append-button.css">
+  <link rel="stylesheet" href="/assets/css/clickable-list.css">
+  <link rel="stylesheet" href="/assets/css/pagination.css">
+
+  <link rel="stylesheet" href="/assets/css/pages/categories.css">
+</head>
+<body>
+
+  <header>
+    <div class="page-box header-main">
+      <div class="header-logo">
+        <img src="/assets/img/logo.svg">
+      </div>
+      {% if user is not null %}
+        <div class="username">
+          <span>{{ user.name }}</span>
+          <span class="material-icons-outlined">account_box</span>
+        </div>
+      {% endif %}
+    </div>
+
+    <div class="page-box header-menu">
+      <div>
+        <span class="margin-right-8 text-primary">Topics</span>
+        {% if userAccess.canManageUsers() %}
+          <a class="margin-right-8 text-gray" href="/users">Users</a>
+        {% endif %}
+        {% if user is null %}
+          <a class="text-gray" href="/login">Login</a>
+        {% else %}
+          <a class="text-gray" href="/logout">Logout</a>
+        {% endif %}
+      </div>
+    </div>
+  </header>
+
+  <main>
+    <div class="page-box">
+      <h1 class="title">All Categories</h1>
+
+      {% if categoryAccess.canAdd() %}
+        <a class="append-button" href="/add-category">
+          <div>Add category</div>
+          <span class="icon material-icons">add</span>
+        </a>
+      {% endif %}
+
+      {% for category in categories %}
+        {% if user is null and category['topics_count'] is 0 %}
+          {% continue %}
+        {% endif %}
+
+        <div class="secondary-title">
+          <h2>
+            <a href="/{{ category['slug'] }}">{{ category['name'] }}</a>
+          </h2>
+          <a class="secondary-title-action" href="/{{ category['slug'] }}">
+            {% if category['topics_count'] > topicsPerCategory %}
+              See all {{ category['topics_count']}} topics
+            {% endif %}
+          </a>
+        </div>
+
+        {% if category['topics_count'] is 0 %}
+          <div style="font-size: 14px;color: #93989f;">No topics yet</div>
+        {% endif %}
+
+        <div class="clickable-list">
+          {% for topic in category['last_topics'] %}
+            <a class="clickable-list-item" href="/{{ category['slug'] }}/{{ topic['slug'] }}">
+              <div>
+                <div>{{ topic['name'] }}</div>
+                <div class="clickable-list-item-sub">
+                  <span class="icon material-icons-outlined">mode_comment</span>
+                  <span>{{ topic['comments_count'] == 0 ? 'no comments yet' : topic['comments_count'] }}</span>
+                </div>
+              </div>
+              <span class="icon material-icons">keyboard_arrow_right</span>
+            </a>
+          {% endfor %}
+        </div>
+
+      {% endfor %}
+    </div>
+  </main>
+
+  <br/>
+</body>
+</html>

app/Forum/Category/Views/show.volt

@@ -0,0 +1,111 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <title>{{ appName }}</title>
+  <link rel="stylesheet" href="/assets/css/material-icons.css">
+  <link rel="stylesheet" href="/assets/css/shared.css">
+  <link rel="stylesheet" href="/assets/css/header.css">
+  <link rel="stylesheet" href="/assets/css/content.css">
+
+  <link rel="stylesheet" href="/assets/css/breadcrumbs.css">
+  <link rel="stylesheet" href="/assets/css/append-button.css">
+  <link rel="stylesheet" href="/assets/css/clickable-list.css">
+  <link rel="stylesheet" href="/assets/css/pagination.css">
+
+  <link rel="stylesheet" href="/assets/css/pages/category.css">
+</head>
+<body>
+
+  <header>
+    <div class="page-box header-main">
+      <div class="header-logo">
+        <img src="/assets/img/logo.svg">
+      </div>
+      {% if user is not null %}
+        <div class="username">
+          <span>{{ user.name }}</span>
+          <span class="material-icons-outlined">account_box</span>
+        </div>
+      {% endif %}
+    </div>
+
+    <div class="page-box header-menu">
+      <div>
+        <span class="margin-right-8 text-primary">Topics</span>
+        {% if userAccess.canManageUsers() %}
+          <a class="margin-right-8 text-gray" href="/users">Users</a>
+        {% endif %}
+        {% if user is null %}
+          <a class="text-gray" href="/login">Login</a>
+        {% else %}
+          <a class="text-gray" href="/logout">Logout</a>
+        {% endif %}
+      </div>
+    </div>
+  </header>
+
+  <main>
+    <div class="page-box">
+      <h1 class="title">
+        <span>{{ category['name'] }}</span>
+        {% if categoryAccess.canChange(category['id']) %}
+          <a href="/categories/{{ category['id'] }}" class="icon material-icons">edit</a>
+        {% endif %}
+      </h1>
+
+      <nav>
+        <ol class="breadcrumbs">
+          <li class="breadcrumbs-item">
+            <a href="/">All categories</a>
+          </li>
+          <li class="breadcrumbs-item active">{{ category['name'] }}</li>
+        </ol>
+      </nav>
+
+      {% if topicAccess.canAdd() %}
+        <a class="append-button margin-bottom-16" href="/{{ category['slug'] }}/add-topic">
+          <div>Add topic</div>
+          <span class="icon material-icons">add</span>
+        </a>
+      {% endif %}
+
+      <div class="clickable-list">
+        {% for topic in topics %}
+          <a class="clickable-list-item" href="/{{ category['slug'] }}/{{ topic['slug'] }}">
+            <div>
+              <div>{{ topic['name'] }}</div>
+              <div class="clickable-list-item-sub">
+                <span class="icon material-icons-outlined">mode_comment</span>
+                <span>{{ topic['comments_count'] == 0 ? 'no comments yet' : topic['comments_count'] }}</span>
+              </div>
+            </div>
+            <span class="icon material-icons">keyboard_arrow_right</span>
+          </a>
+        {% endfor %}
+      </div>
+
+      {% if pages > 1 %}
+        <div class="pagination">
+          <span>{{ page }} of {{ pages }} pages</span>
+          <div>
+            {% if page > 2 %}
+              <a class="pagination-action" href="/{{ category['slug'] }}?page=1">First page</a>
+            {% endif %}
+            {% if page > 1 %}
+              <a class="pagination-action" href="/{{ category['slug'] }}?page={{ page - 1 }}">Back</a>
+            {% endif %}
+            {% if page < pages %}
+              <a class="pagination-action" href="/{{ category['slug'] }}?page={{ page + 1 }}">Next</a>
+            {% endif %}
+            {% if page < pages and (pages - page) > 1 %}
+              <a class="pagination-action" href="/{{ category['slug'] }}?page={{ pages }}">Last page</a>
+            {% endif %}
+          </div>
+        </div>
+      {% endif %}
+    </div>
+  </main>
+
+  <br/>
+</body>
+</html>

app/Forum/Category/config.php

@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+return [
+    'excluding_slugs' => [
+        'access',
+        'login',
+        'logout',
+        'categories',
+        'add-category',
+        'comments',
+        'topics',
+        'users',
+        'add-user',
+    ],
+];

app/Forum/Category/routes.php

@@ -0,0 +1,51 @@
+<?php
+
+declare(strict_types=1);
+
+return [
+    'category:delete' => [
+        'pattern' => '/categories/{id}/delete',
+        'paths' => [
+            'namespace' => 'App\Forum\Category\Controllers',
+            'controller' => 'delete',
+            'action' => 'main',
+        ],
+        'httpMethods' => ['GET'],
+    ],
+    'category:edit' => [
+        'pattern' => '/categories/{id}',
+        'paths' => [
+            'namespace' => 'App\Forum\Category\Controllers',
+            'controller' => 'edit',
+            'action' => 'main',
+        ],
+        'httpMethods' => ['GET', 'POST'],
+    ],
+    'category:show' => [
+        'pattern' => '/{slug}',
+        'paths' => [
+            'namespace' => 'App\Forum\Category\Controllers',
+            'controller' => 'show',
+            'action' => 'main',
+        ],
+        'httpMethods' => ['GET'],
+    ],
+    'category:index' => [
+        'pattern' => '/',
+        'paths' => [
+            'namespace' => 'App\Forum\Category\Controllers',
+            'controller' => 'index',
+            'action' => 'main',
+        ],
+        'httpMethods' => ['GET'],
+    ],
+    'category:add' => [
+        'pattern' => '/add-category',
+        'paths' => [
+            'namespace' => 'App\Forum\Category\Controllers',
+            'controller' => 'add',
+            'action' => 'main',
+        ],
+        'httpMethods' => ['GET', 'POST'],
+    ],
+];

app/Forum/Comment/Controllers/AddController.php

@@ -0,0 +1,137 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Comment\Controllers;
+
+use App\Access\Models\AccessChecker\Forum\CommentAccessChecker;
+use App\Access\Models\Forbidden;
+use App\Auth\Models\Auth;
+use App\Forum\Category\Models\CategoryWriteRepository;
+use App\Forum\Comment\Models\Comment;
+use App\Forum\Comment\Models\CommentWriteRepository;
+use App\Forum\Topic\Models\TopicWriteRepository;
+use App\SharedKernel\Controllers\ModuleViewRender;
+use App\SharedKernel\File\Models\File;
+use App\SharedKernel\Http\RequestFilesNormalizer;
+use App\SharedKernel\Http\Validation;
+use Ramsey\Uuid\Uuid;
+
+final class AddController extends \Phalcon\Mvc\Controller
+{
+    use ModuleViewRender;
+
+    public function mainAction(string $categorySlug, string $topicSlug): void
+    {
+        if (!$this->getCommentAccessChecker()->canAdd()) {
+            throw new Forbidden();
+        }
+
+        $category = $this->getCategoryRepository()->getBySlug($categorySlug);
+        $topic = $this->getTopicRepository()->getByCategoryIdAndSlug(
+            Uuid::fromString($category->id),
+            $topicSlug
+        );
+
+        $replyToId = $this->request->getQuery('reply_to', 'string');
+        $replyToId = $replyToId !== '' ? $replyToId : null;
+        $replyTo = null;
+        if ($replyToId !== null) {
+            $replyTo = $this->getCommentRepository()->get($replyToId);
+        }
+
+        if ($this->request->isPost()) {
+            try {
+                $validation = new Validation([
+                    'content' => 'required|length_between:1,2000',
+                ]);
+
+                $validation->validate($_POST);
+
+                $images = [];
+                if ($_FILES['images']['error'][0] !== 4) {
+                    $images = RequestFilesNormalizer::normalize($_FILES['images']);
+
+                    $maxTotalSize = 1024 * 1024 * 4;
+                    $totalSize = 0;
+
+                    foreach ($images as $image) {
+                        if (!File::isImageMimeType(File::extractMimeType($image['tmp_name']))) {
+                            throw new \InvalidArgumentException('You can attach only images');
+                        }
+
+                        $totalSize = $image['size'];
+                    }
+
+                    if ($totalSize > $maxTotalSize) {
+                        throw new \InvalidArgumentException('Total size of all images must be less than 4MB');
+                    }
+                }
+
+                $user = $this->getAuth()->getUserFromSession();
+                $commentId = Uuid::uuid4();
+
+                Comment::add(
+                    $commentId,
+                    Uuid::fromString($topic->id),
+                    $_POST['content'],
+                    $user !== null ? $user->id : null,
+                    isset($_POST['reply_to']) ? $_POST['reply_to'] : null
+                );
+
+                foreach ($images as $image) {
+                    File::addForForumComment(
+                        Uuid::uuid4(),
+                        $commentId,
+                        $image['tmp_name'],
+                        $image['name']
+                    );
+                }
+
+                $this->response->redirect("/$categorySlug/$topicSlug");
+
+                return;
+            } catch (\InvalidArgumentException $e) {
+                $this->renderView([
+                    'category' => $category,
+                    'topic' => $topic,
+                    'replyTo' => $replyTo,
+                    'error' => $e->getMessage(),
+                ]);
+
+                return;
+            }
+        }
+
+        $this->renderView([
+            'category' => $category,
+            'topic' => $topic,
+            'replyTo' => $replyTo,
+        ]);
+    }
+
+    private function getCommentRepository(): CommentWriteRepository
+    {
+        return new CommentWriteRepository();
+    }
+
+    private function getCategoryRepository(): CategoryWriteRepository
+    {
+        return new CategoryWriteRepository();
+    }
+
+    private function getTopicRepository(): TopicWriteRepository
+    {
+        return new TopicWriteRepository();
+    }
+
+    private function getCommentAccessChecker(): CommentAccessChecker
+    {
+        return new CommentAccessChecker();
+    }
+
+    private function getAuth(): Auth
+    {
+        return new Auth();
+    }
+}

app/Forum/Comment/Controllers/DeleteController.php

@@ -0,0 +1,49 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Comment\Controllers;
+
+use App\Access\Models\AccessChecker\Forum\CommentAccessChecker;
+use App\Access\Models\Forbidden;
+use App\Forum\Category\Models\CategoryWriteRepository;
+use App\Forum\Comment\Models\CommentWriteRepository;
+use App\Forum\Topic\Models\TopicWriteRepository;
+
+final class DeleteController extends \Phalcon\Mvc\Controller
+{
+    public function mainAction(string $id): void
+    {
+        $comment = $this->getCommentRepository()->get($id);
+        $topic = $this->getTopicRepository()->get($comment->topic_id);
+        $category = $this->getCategoryRepository()->get($topic->category_id);
+
+        if (!$this->getCommentAccessChecker()->canDelete($topic->category_id, $comment->created_by)) {
+            throw new Forbidden();
+        }
+
+        $this->getCommentRepository()->get($id)->delete();
+
+        $this->response->redirect('/' . $category->slug . '/' . $topic->slug);
+    }
+
+    private function getCommentAccessChecker(): CommentAccessChecker
+    {
+        return new CommentAccessChecker();
+    }
+
+    private function getTopicRepository(): TopicWriteRepository
+    {
+        return new TopicWriteRepository();
+    }
+
+    private function getCommentRepository(): CommentWriteRepository
+    {
+        return new CommentWriteRepository();
+    }
+
+    private function getCategoryRepository(): CategoryWriteRepository
+    {
+        return new CategoryWriteRepository();
+    }
+}

app/Forum/Comment/Controllers/EditController.php

@@ -0,0 +1,128 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Comment\Controllers;
+
+use App\Access\Models\AccessChecker\Forum\CommentAccessChecker;
+use App\Access\Models\AccessChecker\Forum\TopicAccessChecker;
+use App\Access\Models\Forbidden;
+use App\Auth\Models\Auth;
+use App\Forum\Category\Models\CategoryWriteRepository;
+use App\Forum\Comment\Models\CommentWriteRepository;
+use App\Forum\Topic\Models\TopicWriteRepository;
+use App\SharedKernel\Controllers\ModuleViewRender;
+use App\SharedKernel\File\Models\File;
+use App\SharedKernel\File\Models\FileRepository;
+use App\SharedKernel\Http\RequestFilesNormalizer;
+use App\SharedKernel\Http\Validation;
+use Ramsey\Uuid\Uuid;
+
+final class EditController extends \Phalcon\Mvc\Controller
+{
+    use ModuleViewRender;
+
+    public function mainAction(string $id): void
+    {
+        $comment = $this->getCommentRepository()->get($id);
+        $topic = $this->getTopicRepository()->get($comment->topic_id);
+        $category = $this->getCategoryRepository()->get($topic->category_id);
+
+        if (!$this->getCommentAccessChecker()->canChange($topic->category_id, $comment->created_by)) {
+            throw new Forbidden();
+        }
+
+        if ($this->request->isPost()) {
+            try {
+                $validation = new Validation([
+                    'content' => 'required|length_between:1,2000',
+                ]);
+
+                $validation->validate($_POST);
+
+                $images = [];
+                if ($_FILES['images']['error'][0] !== 4) {
+                    $images = RequestFilesNormalizer::normalize($_FILES['images']);
+
+                    $maxTotalSize = 1024 * 1024 * 4;
+                    $totalSize = 0;
+
+                    foreach ($images as $image) {
+                        if (!File::isImageMimeType(File::extractMimeType($image['tmp_name']))) {
+                            throw new \InvalidArgumentException('You can attach only images');
+                        }
+
+                        $totalSize = $image['size'];
+                    }
+
+                    if ($totalSize > $maxTotalSize) {
+                        throw new \InvalidArgumentException('Total size of all images must be less than 4MB');
+                    }
+                }
+
+                $user = $this->getAuth()->getUserFromSession();
+
+                $comment->edit($_POST['content'], $user->id);
+
+                foreach ($images as $image) {
+                    File::addForForumComment(
+                        Uuid::uuid4(),
+                        $comment->id,
+                        $image['tmp_name'],
+                        $image['name']
+                    );
+                }
+
+                $this->response->redirect('/' . $category->slug . '/' . $topic->slug);
+
+                return;
+            } catch (\InvalidArgumentException $e) {
+                $this->renderView([
+                    'category' => $category,
+                    'topic' => $topic,
+                    'comment' => $comment,
+                    'images' => $this->getFileRepository()->findByForumCommentId($comment->id),
+                    'error' => $e->getMessage(),
+                    'content' => $_POST['content']
+                ]);
+            }
+        }
+
+        $this->renderView([
+            'category' => $category,
+            'topic' => $topic,
+            'comment' => $comment,
+            'images' => $this->getFileRepository()->findByForumCommentId($comment->id),
+        ]);
+    }
+
+    private function getFileRepository(): FileRepository
+    {
+        return new FileRepository();
+    }
+
+    private function getAuth(): Auth
+    {
+        return new Auth();
+    }
+
+    private function getCommentAccessChecker(): CommentAccessChecker
+    {
+        return new CommentAccessChecker();
+    }
+
+    private function getCommentRepository(): CommentWriteRepository
+    {
+        return new CommentWriteRepository();
+    }
+
+    private function getCategoryRepository(): CategoryWriteRepository
+    {
+        return new CategoryWriteRepository();
+    }
+
+    private function getTopicRepository(): TopicWriteRepository
+    {
+        return new TopicWriteRepository();
+    }
+}

app/Forum/Comment/Models/Comment.php

@@ -0,0 +1,81 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Comment\Models;
+
+use App\SharedKernel\File\Models\FileRepository;
+use App\User\Models\UserNotFound;
+use App\User\Models\UserRepository;
+use Ramsey\Uuid\UuidInterface;
+
+final class Comment extends \Phalcon\Mvc\Model
+{
+    public function initialize(): void
+    {
+        $this->setSource('forum_comments');
+    }
+
+    public static function add(UuidInterface $id, UuidInterface $topicId, string $content, $userId = null, $replyTo = null): void
+    {
+        $comment = new self([
+            'id' => $id,
+            'topic_id' => $topicId,
+            'content' => $content,
+            'created_at' => (new \DateTime('now'))->format('Y-m-d H:i:s'),
+            'created_by' => $userId,
+            'reply_to' => $replyTo,
+        ]);
+
+        $comment->save();
+    }
+
+    public function edit(string $content, $userId): void
+    {
+        $this->content = $content;
+        $this->updated_at = (new \DateTime('now'))->format('Y-m-d H:i:s');
+        $this->updated_by = $userId;
+
+        $this->save();
+    }
+
+    public function delete(): void
+    {
+        foreach ((new FileRepository())->findByForumCommentId($this->id) as $file) {
+            $file->delete();
+        }
+
+        parent::delete();
+    }
+
+    public function getAuthorName(): string
+    {
+        $userRepository = new UserRepository();
+
+        try {
+            return $userRepository->get($this->created_by)->name;
+        } catch (UserNotFound $e) {
+            return 'anonymous';
+        }
+    }
+
+    public function getReadableDate(): string
+    {
+        $date = new \DateTime($this->created_at);
+
+        return $date->format('H:i d.m.Y');
+    }
+
+    public function getReplyTo(): ?Comment
+    {
+        if ($this->reply_to === null) {
+            return null;
+        }
+
+        try {
+            return (new CommentWriteRepository())->get($this->reply_to);
+        } catch (CommentNotFound $e) {
+            return null;
+        }
+    }
+}

app/Forum/Comment/Models/CommentNotFound.php

@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Comment\Models;
+
+use App\SharedKernel\Exceptions\NotFoundException;
+
+final class CommentNotFound extends NotFoundException
+{
+
+}

app/Forum/Comment/Models/CommentReadRepository.php

@@ -0,0 +1,43 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Comment\Models;
+
+final class CommentReadRepository
+{
+    public function findByTopicId(string $topicId, int $count, int $skip = 0): array
+    {
+        $connection = \Phalcon\DI::getDefault()->getShared('db');
+
+        $sql = <<<SQL
+SELECT
+       forum_comments.id,
+       forum_comments.content,
+       coalesce(users.name, 'anonymous') as author_name,
+       forum_comments.created_by as authour_id,
+       forum_comments.created_at,
+       forum_comments.reply_to as reply_to_id,
+       reply_to.content as reply_to_content
+FROM forum_comments
+    LEFT JOIN forum_comments as reply_to ON reply_to.id = forum_comments.reply_to
+    LEFT JOIN users ON users.id = forum_comments.created_by
+WHERE forum_comments.topic_id = '$topicId'
+ORDER BY forum_comments.created_at DESC
+LIMIT $count OFFSET $skip
+SQL;
+
+        $query = $connection->query($sql);
+        $query->setFetchMode(\Phalcon\Db::FETCH_ASSOC);
+
+        return $query->fetchAll();
+    }
+
+    public function countByTopicId(string $topicId): int
+    {
+        $connection = \Phalcon\DI::getDefault()->getShared('db');
+        $query = $connection->query("SELECT count(id) FROM forum_comments WHERE topic_id = '$topicId'");
+
+        return (int) $query->fetch()[0];
+    }
+}

app/Forum/Comment/Models/CommentWriteRepository.php

@@ -0,0 +1,50 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Comment\Models;
+
+use App\SharedKernel\TimeSorting;
+use Phalcon\Mvc\Model\Resultset;
+use Ramsey\Uuid\UuidInterface;
+
+final class CommentWriteRepository
+{
+    public function get($id): Comment
+    {
+        $comment = Comment::findFirst("id = '$id'");
+
+        if ($comment === false) {
+            throw new CommentNotFound();
+        }
+
+        return $comment;
+    }
+
+    public function countByTopicId(UuidInterface $topicId): int
+    {
+        return Comment::count("topic_id = '$topicId'");
+    }
+
+    public function findByTopicId(UuidInterface $topicId, TimeSorting $timeSorting, int $page, int $limit): Resultset
+    {
+        $sortingDirection = $timeSorting == TimeSorting::newest() ? 'desc' : 'asc';
+
+        return Comment::find([
+            "topic_id = '$topicId'",
+            'order' => 'created_at ' . $sortingDirection,
+            'limit' => $limit,
+            'offset' => ($page - 1) * $limit,
+        ]);
+    }
+
+    public function findAllByTopicId($topicId): Resultset
+    {
+        return Comment::find([
+            'conditions' => 'topic_id = :topic_id:',
+            'bind' => [
+                'topic_id' => $topicId,
+            ],
+        ]);
+    }
+}

app/Forum/Comment/Views/add.volt

@@ -0,0 +1,101 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <title>{{ appName }}</title>
+  <link rel="stylesheet" href="/assets/css/material-icons.css">
+  <link rel="stylesheet" href="/assets/css/shared.css">
+  <link rel="stylesheet" href="/assets/css/header.css">
+
+  <link rel="stylesheet" href="/assets/css/breadcrumbs.css">
+  <link rel="stylesheet" href="/assets/css/form.css">
+
+  <link rel="stylesheet" href="/assets/css/pages/add-category.css">
+</head>
+<body>
+
+<header>
+  <div class="page-box header-main">
+    <div class="header-logo">
+      <img src="/assets/img/logo.svg">
+    </div>
+    {% if user is not null %}
+      <div class="username">
+        <span>{{ user.name }}</span>
+        <span class="material-icons-outlined">account_box</span>
+      </div>
+    {% endif %}
+  </div>
+
+  <div class="page-box header-menu">
+    <div>
+      <span class="margin-right-8 text-primary">Topics</span>
+      {% if userAccess.canManageUsers() %}
+        <a class="margin-right-8 text-gray" href="/users">Users</a>
+      {% endif %}
+      {% if user is null %}
+        <a class="text-gray" href="/login">Login</a>
+      {% else %}
+        <a class="text-gray" href="/logout">Logout</a>
+      {% endif %}
+    </div>
+  </div>
+</header>
+
+<main>
+  <div class="page-box">
+    <h1 class="title">Add comment</h1>
+
+    <nav>
+      <ol class="breadcrumbs">
+        <li class="breadcrumbs-item">
+          <a href="/">All categories</a>
+        </li>
+        <li class="breadcrumbs-item">
+          <a href="/{{ category.slug }}">{{ category.name }}</a>
+        </li>
+        <li class="breadcrumbs-item">
+          <a href="/{{ category.slug }}/{{ topic.slug }}">{{ topic.name }}</a>
+        </li>
+        <li class="breadcrumbs-item active">Add comment</li>
+      </ol>
+    </nav>
+
+    {% if replyTo is not null %}
+      <div style="padding-left: 4px;
+    border-left: 2px solid #6d757d;
+    margin-bottom: 24px;
+    margin-left: 4px;
+    color: #6d757d;
+    font-size: 14px;">
+        {{ replyTo.content }}
+      </div>
+    {% endif %}
+
+    {% if error is not null %}
+      <div class="error" style="color: #000000;
+    width: 100%;
+    margin-bottom: 24px;margin-top: -8px;">
+        {{ error }}
+      </div>
+    {% endif %}
+
+    <form action="/{{ category.slug }}/{{ topic.slug }}/add-comment" method="post" enctype="multipart/form-data">
+      {% if replyTo is not null %}
+        <input type="hidden" name="reply_to" value="{{ replyTo.id }}" />
+      {% endif %}
+      <div class="margin-bottom-16">
+        {% if content is not null %}
+          <textarea class="form-input" name="content" rows="3" placeholder="Type your comment here..." required>{{ content }}</textarea>
+        {% else %}
+          <textarea class="form-input" name="content" rows="3" placeholder="Type your comment here..." required></textarea>
+        {% endif %}
+      </div>
+      <div>
+        <input name="images[]" type="file" multiple />
+      </div>
+      <button class="form-button" type="submit">Add comment</button>
+    </form>
+  </div>
+</main>
+</body>
+</html>

app/Forum/Comment/Views/edit.volt

@@ -0,0 +1,97 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <title>{{ appName }}</title>
+  <link rel="stylesheet" href="/assets/css/material-icons.css">
+  <link rel="stylesheet" href="/assets/css/shared.css">
+  <link rel="stylesheet" href="/assets/css/header.css">
+
+  <link rel="stylesheet" href="/assets/css/breadcrumbs.css">
+  <link rel="stylesheet" href="/assets/css/form.css">
+  <link rel="stylesheet" href="/assets/css/clickable-list.css">
+
+  <link rel="stylesheet" href="/assets/css/pages/add-category.css">
+</head>
+<body>
+
+<header>
+  <div class="page-box header-main">
+    <div class="header-logo">
+      <img src="/assets/img/logo.svg">
+    </div>
+    {% if user is not null %}
+      <div class="username">
+        <span>{{ user.name }}</span>
+        <span class="material-icons-outlined">account_box</span>
+      </div>
+    {% endif %}
+  </div>
+
+  <div class="page-box header-menu">
+    <div>
+      <span class="margin-right-8 text-primary">Topics</span>
+      {% if userAccess.canManageUsers() %}
+        <a class="margin-right-8 text-gray" href="/users">Users</a>
+      {% endif %}
+      {% if user is null %}
+        <a class="text-gray" href="/login">Login</a>
+      {% else %}
+        <a class="text-gray" href="/logout">Logout</a>
+      {% endif %}
+    </div>
+  </div>
+</header>
+
+<main>
+  <div class="page-box">
+    <h1 class="title">Edit comment</h1>
+
+    <nav>
+      <ol class="breadcrumbs">
+        <li class="breadcrumbs-item">
+          <a href="/">All categories</a>
+        </li>
+        <li class="breadcrumbs-item">
+          <a href="/{{ category.slug }}">{{ category.name }}</a>
+        </li>
+        <li class="breadcrumbs-item">
+          <a href="/{{ category.slug }}/{{ topic.slug }}">{{ topic.name }}</a>
+        </li>
+        <li class="breadcrumbs-item active">Edit comment</li>
+      </ol>
+    </nav>
+
+    {% if error is not null %}
+      <div class="error" style="color: #000000;
+    width: 100%;
+    margin-bottom: 24px;margin-top: -8px;">
+        {{ error }}
+      </div>
+    {% endif %}
+
+    <form action="/comments/{{ comment.id }}" method="post" enctype="multipart/form-data">
+      <div class="margin-bottom-16">
+        <textarea class="form-input" name="content" rows="3" placeholder="Content">{{ content is not null ? content : comment.content }}</textarea>
+      </div>
+      <div>
+        <input name="images[]" type="file" multiple />
+      </div>
+      <button class="form-button" type="submit">Update</button>
+    </form>
+
+    <div class="clickable-list margin-top-24 margin-bottom-32">
+      {% for image in images %}
+        <div class="clickable-list-item">
+          <div>
+            <a href="/images/{{ image.id }}" target="_blank">
+              <img style="max-width: 160px;max-height: 160px;" src="{{ image.getImageBase64Content() }}">
+            </a>
+          </div>
+          <a href="/files/{{ image.id }}/delete?redirect_to=/comments/{{ comment.id }}" class="icon material-icons">delete</a>
+        </div>
+      {% endfor %}
+    </div>
+  </div>
+</main>
+</body>
+</html>

app/Forum/Comment/config.php

@@ -0,0 +1,5 @@
+<?php
+
+declare(strict_types=1);
+
+return [];

app/Forum/Comment/routes.php

@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+return [
+    'comment:add' => [
+        'pattern' => '/{categorySlug}/{topicSlug}/add-comment',
+        'paths' => [
+            'namespace' => 'App\Forum\Comment\Controllers',
+            'controller' => 'add',
+            'action' => 'main',
+        ],
+        'httpMethods' => ['GET', 'POST'],
+    ],
+    'comment:delete' => [
+        'pattern' => '/comments/{id}/delete',
+        'paths' => [
+            'namespace' => 'App\Forum\Comment\Controllers',
+            'controller' => 'delete',
+            'action' => 'main',
+        ],
+        'httpMethods' => ['GET'],
+    ],
+    'comment:edit' => [
+        'pattern' => '/comments/{id}',
+        'paths' => [
+            'namespace' => 'App\Forum\Comment\Controllers',
+            'controller' => 'edit',
+            'action' => 'main',
+        ],
+        'httpMethods' => ['GET', 'POST'],
+    ],
+];

app/Forum/Topic/Controllers/AddController.php

@@ -0,0 +1,109 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Topic\Controllers;
+
+use App\Access\Models\AccessChecker\Forum\TopicAccessChecker;
+use App\Access\Models\Forbidden;
+use App\Auth\Models\Auth;
+use App\Forum\Category\Models\CategoryWriteRepository;
+use App\Forum\Topic\Models\Topic;
+use App\SharedKernel\Controllers\ModuleViewRender;
+use App\SharedKernel\Controllers\Validation;
+use App\SharedKernel\File\Models\File;
+use App\SharedKernel\Http\RequestFilesNormalizer;
+use Ramsey\Uuid\Uuid;
+
+final class AddController extends \Phalcon\Mvc\Controller
+{
+    use ModuleViewRender;
+    use Validation;
+
+    public function mainAction(string $categorySlug): void
+    {
+        if (!$this->getTopicAccessChecker()->canAdd()) {
+            throw new Forbidden();
+        }
+
+        $category = $this->getCategoryRepository()->getBySlug($categorySlug);
+
+        if ($this->request->isPost()) {
+            try {
+                $this->validatePostRequest([
+                    'name' => 'required|length_between:1,64',
+                    'content' => 'required|length_between:1,20000',
+                ]);
+
+                $images = [];
+                if ($_FILES['images']['error'][0] !== 4) {
+                    $images = RequestFilesNormalizer::normalize($_FILES['images']);
+
+                    $maxTotalSize = 1024 * 1024 * 4;
+                    $totalSize = 0;
+
+                    foreach ($images as $image) {
+                        if (!File::isImageMimeType(File::extractMimeType($image['tmp_name']))) {
+                            throw new \InvalidArgumentException('You can attach only images');
+                        }
+
+                        $totalSize = $image['size'];
+                    }
+
+                    if ($totalSize > $maxTotalSize) {
+                        throw new \InvalidArgumentException('Total size of all images must be less than 4MB');
+                    }
+                }
+
+                $user = $this->getAuth()->getUserFromSession();
+
+                $topic = Topic::add(
+                    Uuid::uuid4(),
+                    Uuid::fromString($category->id),
+                    $_POST['name'],
+                    $_POST['content'],
+                    Uuid::fromString($user->id)
+                );
+
+                foreach ($images as $image) {
+                    File::addForForumTopic(
+                        Uuid::uuid4(),
+                        $topic->id,
+                        $image['tmp_name'],
+                        $image['name']
+                    );
+                }
+
+                $this->response->redirect('/' . $categorySlug . '/' . $topic->slug);
+
+                return;
+            } catch (\InvalidArgumentException $e) {
+                $this->renderView([
+                    'category' => $category,
+                    'error' => $e->getMessage(),
+                    'name' => $_POST['name'],
+                    'content' => $_POST['content'],
+                ]);
+
+                return;
+            }
+        }
+
+        $this->renderView(['category' => $category]);
+    }
+
+    private function getTopicAccessChecker(): TopicAccessChecker
+    {
+        return new TopicAccessChecker();
+    }
+
+    private function getAuth(): Auth
+    {
+        return new Auth();
+    }
+
+    private function getCategoryRepository(): CategoryWriteRepository
+    {
+        return new CategoryWriteRepository();
+    }
+}

app/Forum/Topic/Controllers/DeleteController.php

@@ -0,0 +1,43 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Topic\Controllers;
+
+use App\Access\Models\AccessChecker\Forum\TopicAccessChecker;
+use App\Access\Models\Forbidden;
+use App\Forum\Category\Models\CategoryWriteRepository;
+use App\Forum\Topic\Models\TopicWriteRepository;
+
+final class DeleteController extends \Phalcon\Mvc\Controller
+{
+    public function mainAction(string $id): void
+    {
+        $topic = $this->getTopicRepository()->get($id);
+        $category = $this->getCategoryRepository()->get($topic->category_id);
+
+        if (!$this->getTopicAccessChecker()->canDelete($topic->category_id, $topic->created_by)) {
+            throw new Forbidden();
+        }
+
+        $topic = $this->getTopicRepository()->get($id);
+        $topic->delete();
+
+        $this->response->redirect('/' . $category->slug);
+    }
+
+    private function getTopicAccessChecker(): TopicAccessChecker
+    {
+        return new TopicAccessChecker();
+    }
+
+    private function getTopicRepository(): TopicWriteRepository
+    {
+        return new TopicWriteRepository();
+    }
+
+    private function getCategoryRepository(): CategoryWriteRepository
+    {
+        return new CategoryWriteRepository();
+    }
+}

app/Forum/Topic/Controllers/EditController.php

@@ -0,0 +1,125 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Topic\Controllers;
+
+use App\Access\Models\AccessChecker\Forum\TopicAccessChecker;
+use App\Access\Models\Forbidden;
+use App\Auth\Models\Auth;
+use App\Forum\Category\Models\CategoryWriteRepository;
+use App\Forum\Topic\Models\TopicWriteRepository;
+use App\SharedKernel\Controllers\ModuleViewRender;
+use App\SharedKernel\Controllers\Validation;
+use App\SharedKernel\File\Models\File;
+use App\SharedKernel\File\Models\FileRepository;
+use App\SharedKernel\Http\RequestFilesNormalizer;
+use Ramsey\Uuid\Uuid;
+
+final class EditController extends \Phalcon\Mvc\Controller
+{
+    use ModuleViewRender;
+    use Validation;
+
+    public function mainAction(string $id): void
+    {
+        $topic = $this->getTopicRepository()->get($id);
+        $category = $this->getCategoryRepository()->get($topic->category_id);
+
+        if (!$this->getTopicAccessChecker()->canChange($topic->category_id, $topic->created_by)) {
+            throw new Forbidden();
+        }
+
+        if ($this->request->isPost()) {
+            try {
+                $this->validatePostRequest([
+                    'name' => 'required|length_between:1,64',
+                    'content' => 'required|length_between:1,20000',
+                ]);
+
+                $images = [];
+                if ($_FILES['images']['error'][0] !== 4) {
+                    $images = RequestFilesNormalizer::normalize($_FILES['images']);
+
+                    $maxTotalSize = 1024 * 1024 * 4;
+                    $totalSize = 0;
+
+                    foreach ($images as $image) {
+                        if (!File::isImageMimeType(File::extractMimeType($image['tmp_name']))) {
+                            throw new \InvalidArgumentException('You can attach only images');
+                        }
+
+                        $totalSize = $image['size'];
+                    }
+
+                    if ($totalSize > $maxTotalSize) {
+                        throw new \InvalidArgumentException('Total size of all images must be less than 4MB');
+                    }
+                }
+
+                $user = $this->getAuth()->getUserFromSession();
+
+                $topic->edit(
+                    $_POST['name'],
+                    $_POST['content'],
+                    $user->id
+                );
+
+                foreach ($images as $image) {
+                    File::addForForumTopic(
+                        Uuid::uuid4(),
+                        $topic->id,
+                        $image['tmp_name'],
+                        $image['name']
+                    );
+                }
+
+                $this->response->redirect('/' . $category->slug . '/' . $topic->slug);
+
+                return;
+            } catch (\InvalidArgumentException $e) {
+                $this->renderView([
+                    'category' => $category,
+                    'topic' => $topic,
+                    'images' => $this->getFileRepository()->findByForumTopicId($topic->id),
+                    'name' => $_POST['name'],
+                    'content' => $_POST['content'],
+                    'error' => $e->getMessage(),
+                ]);
+
+                return;
+            }
+        }
+
+        $this->renderView([
+            'category' => $category,
+            'topic' => $topic,
+            'images' => $this->getFileRepository()->findByForumTopicId($topic->id),
+        ]);
+    }
+
+    private function getFileRepository(): FileRepository
+    {
+        return new FileRepository();
+    }
+
+    private function getTopicAccessChecker(): TopicAccessChecker
+    {
+        return new TopicAccessChecker();
+    }
+
+    private function getAuth(): Auth
+    {
+        return new Auth();
+    }
+
+    private function getCategoryRepository(): CategoryWriteRepository
+    {
+        return new CategoryWriteRepository();
+    }
+
+    private function getTopicRepository(): TopicWriteRepository
+    {
+        return new TopicWriteRepository();
+    }
+}

app/Forum/Topic/Controllers/ShowController.php

@@ -0,0 +1,76 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Topic\Controllers;
+
+use App\Forum\Category\Models\CategoryReadRepository;
+use App\Forum\Comment\Models\CommentReadRepository;
+use App\Forum\Topic\Models\TopicReadRepository;
+use App\SharedKernel\Controllers\ModuleViewRender;
+use App\SharedKernel\File\Models\FileRepository;
+
+final class ShowController extends \Phalcon\Mvc\Controller
+{
+    use ModuleViewRender;
+
+    public function mainAction(string $categorySlug, string $slug): void
+    {
+        $page = (int) $this->request->getQuery('page', 'int', 1);
+
+        $category = $this->getCategoryReadRepository()->getBySlug($categorySlug);
+        $topic = $this->getTopicReadRepository()->getByCategoryIdAndSlug($category['id'], $slug);
+
+        $comments = $this->getCommentReadRepository()
+            ->findByTopicId(
+                $topic['id'],
+                10,
+                ($page - 1) * 10
+            );
+
+        $commentIds = [];
+        foreach ($comments as $comment) {
+            $commentIds[] = $comment['id'];
+        }
+
+        if ($commentIds !== []) {
+            $viewableCommentImages = [];
+            $commentImages = $this->getFileRepository()->findByForumCommentsIds($commentIds);
+            foreach ($commentImages as $commentImage) {
+                $viewableCommentImages[$commentImage->relation_id][] = $commentImage->id;
+            }
+        }
+
+        $this->renderView([
+            'category' => $category,
+            'topic' => $topic,
+            'images' => $this->getFileRepository()->findByForumTopicId($topic['id']),
+            'comments' => $comments,
+            'commentImages' => $viewableCommentImages ?? [],
+            'categorySlug' => $categorySlug,
+            'topicSlug' => $slug,
+            'page' => $page,
+            'pages' => ceil($this->getCommentReadRepository()->countByTopicId($topic['id']) / 10),
+        ]);
+    }
+
+    private function getCategoryReadRepository(): CategoryReadRepository
+    {
+        return new CategoryReadRepository();
+    }
+
+    private function getTopicReadRepository(): TopicReadRepository
+    {
+        return new TopicReadRepository();
+    }
+
+    private function getFileRepository(): FileRepository
+    {
+        return new FileRepository();
+    }
+
+    private function getCommentReadRepository(): CommentReadRepository
+    {
+        return new CommentReadRepository();
+    }
+}

app/Forum/Topic/Models/Topic.php

@@ -0,0 +1,59 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Topic\Models;
+
+use App\Forum\Comment\Models\CommentWriteRepository;
+use App\SharedKernel\File\Models\FileRepository;
+use App\SharedKernel\StringConverter;
+use Ramsey\Uuid\UuidInterface;
+
+final class Topic extends \Phalcon\Mvc\Model
+{
+    public function initialize(): void
+    {
+        $this->setSource('forum_topics');
+    }
+
+    public static function add($id, $categoryId, string $name, string $content, $userId): self
+    {
+        $topic = new Topic([
+            'id' => $id,
+            'category_id' => $categoryId,
+            'name' => $name,
+            'slug' => UniqueSlugGenerator::generate($name),
+            'content' => $content,
+            'created_at' => (new \DateTime('now'))->format('Y-m-d H:i:s'),
+            'created_by' => $userId,
+        ]);
+
+        $topic->save();
+
+        return $topic;
+    }
+
+    public function edit(string $name, string $content, $userId): void
+    {
+        $this->name = $name;
+        $this->slug = UniqueSlugGenerator::generate($name);
+        $this->content = $content;
+        $this->updated_at = (new \DateTime('now'))->format('Y-m-d H:i:s');
+        $this->updated_by = $userId;
+
+        $this->save();
+    }
+
+    public function delete(): void
+    {
+        foreach ((new CommentWriteRepository())->findAllByTopicId($this->id) as $comment) {
+            $comment->delete();
+        }
+
+        foreach ((new FileRepository())->findByForumTopicId($this->id) as $file) {
+            $file->delete();
+        }
+
+        parent::delete();
+    }
+}

app/Forum/Topic/Models/TopicNotFound.php

@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Topic\Models;
+
+use App\SharedKernel\Exceptions\NotFoundException;
+
+final class TopicNotFound extends NotFoundException
+{
+
+}

app/Forum/Topic/Models/TopicReadRepository.php

@@ -0,0 +1,90 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Topic\Models;
+
+final class TopicReadRepository
+{
+    public function existBySlug(string $slug): bool
+    {
+        $connection = \Phalcon\DI::getDefault()->getShared('db');
+        $query = $connection->query("SELECT count(id) FROM forum_topics WHERE slug = '$slug'");
+
+        return 0 !== (int) $query->fetch()[0];
+    }
+
+    public function findByCategoryIdOrderedByLastActivity(string $categoryId, int $count, int $skip = 0): array
+    {
+        $connection = \Phalcon\DI::getDefault()->getShared('db');
+
+        $sql = <<<SQL
+SELECT 
+       forum_topics.id,
+       forum_topics.name,
+       forum_topics.slug,
+       COALESCE(comments_count.comments_count, 0) as comments_count,
+       users.id as author_id,
+       users.name as author_name
+FROM forum_topics
+    LEFT JOIN (
+        SELECT topic_id, max(created_at) as created_at
+        FROM forum_comments
+        GROUP BY 1
+    ) last_comment ON last_comment.topic_id = forum_topics.id
+    LEFT JOIN (
+        SELECT topic_id, count(id) as comments_count
+        FROM forum_comments
+        GROUP BY 1 
+    ) comments_count ON comments_count.topic_id = forum_topics.id
+    LEFT JOIN users ON users.id = forum_topics.created_by
+WHERE category_id = '$categoryId'
+ORDER BY forum_topics.created_at DESC, last_comment.created_at DESC
+LIMIT $count OFFSET $skip
+SQL;
+
+        $query = $connection->query($sql);
+        $query->setFetchMode(\Phalcon\Db::FETCH_ASSOC);
+
+        return $query->fetchAll();
+    }
+
+    public function countByCategoryId(string $categoryId): int
+    {
+        $connection = \Phalcon\DI::getDefault()->getShared('db');
+        $query = $connection->query("SELECT count(id) FROM forum_topics WHERE category_id = '$categoryId'");
+
+        return (int) $query->fetch()[0];
+    }
+
+    public function getByCategoryIdAndSlug(string $categoryId, string $slug): array
+    {
+        $connection = \Phalcon\DI::getDefault()->getShared('db');
+
+        $sql = <<<SQL
+SELECT
+       forum_topics.id,
+       forum_topics.category_id,
+       forum_topics.name,
+       forum_topics.slug,
+       forum_topics.content,
+       forum_topics.created_at,
+       users.id as author_id,
+       users.name as author_name,
+       comments_count.comments_count
+FROM forum_topics
+    LEFT JOIN users ON users.id = forum_topics.created_by
+    LEFT JOIN (
+        SELECT topic_id, count(id) as comments_count
+        FROM forum_comments
+        GROUP BY 1 
+    ) comments_count ON comments_count.topic_id = forum_topics.id
+WHERE category_id = '$categoryId' AND slug = '$slug'
+SQL;
+
+        $query = $connection->query($sql);
+        $query->setFetchMode(\Phalcon\Db::FETCH_ASSOC);
+
+        return $query->fetch();
+    }
+}

app/Forum/Topic/Models/TopicWriteRepository.php

@@ -0,0 +1,43 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Topic\Models;
+
+use Phalcon\Mvc\Model\Resultset;
+use Ramsey\Uuid\UuidInterface;
+
+final class TopicWriteRepository
+{
+    public function get($id): Topic
+    {
+        $topic = Topic::findFirst("id = '$id'");
+
+        if ($topic === false) {
+            throw new TopicNotFound();
+        }
+
+        return $topic;
+    }
+
+    public function getByCategoryIdAndSlug(UuidInterface $categoryId, string $slug): Topic
+    {
+        $topic = Topic::findFirst("category_id = '$categoryId' and slug = '$slug'");
+
+        if ($topic === false) {
+            throw new TopicNotFound();
+        }
+
+        return $topic;
+    }
+
+    public function findByCategoryId($categoryId): Resultset
+    {
+        return Topic::find([
+            'conditions' => 'category_id = :category_id:',
+            'bind' => [
+                'category_id' => $categoryId,
+            ],
+        ]);
+    }
+}

app/Forum/Topic/Models/UniqueSlugGenerator.php

@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Forum\Topic\Models;
+
+use App\SharedKernel\StringConverter;
+
+final class UniqueSlugGenerator
+{
+    public static function generate(string $name): string
+    {
+        $config = include __DIR__ . '/../config.php';
+        $categoryReadRepository = new TopicReadRepository();
+        $number = 0;
+
+        while (true) {
+            $slug = StringConverter::readableToSlug($name) . ($number === 0 ? '' : '-' . $number);
+
+            if (!in_array($slug, $config['excluding_slugs']) && !$categoryReadRepository->existBySlug($slug)) {
+                return $slug;
+            }
+
+            $number++;
+        }
+    }
+}

app/Forum/Topic/Views/add.volt

@@ -0,0 +1,114 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <title>{{ appName }}</title>
+  <link rel="stylesheet" href="/assets/css/material-icons.css">
+  <link rel="stylesheet" href="/assets/css/shared.css">
+  <link rel="stylesheet" href="/assets/css/header.css">
+
+  <link rel="stylesheet" href="/assets/css/breadcrumbs.css">
+  <link rel="stylesheet" href="/assets/css/form.css">
+
+  <link rel="stylesheet" href="/assets/css/pages/add-category.css">
+
+  <link rel="stylesheet" href="/assets/quill/quill.snow.css">
+</head>
+<body>
+
+<header>
+  <div class="page-box header-main">
+    <div class="header-logo">
+      <img src="/assets/img/logo.svg">
+    </div>
+    {% if user is not null %}
+      <div class="username">
+        <span>{{ user.name }}</span>
+        <span class="material-icons-outlined">account_box</span>
+      </div>
+    {% endif %}
+  </div>
+
+  <div class="page-box header-menu">
+    <div>
+      <span class="margin-right-8 text-primary">Topics</span>
+      {% if userAccess.canManageUsers() %}
+        <a class="margin-right-8 text-gray" href="/users">Users</a>
+      {% endif %}
+      {% if user is null %}
+        <a class="text-gray" href="/login">Login</a>
+      {% else %}
+        <a class="text-gray" href="/logout">Logout</a>
+      {% endif %}
+    </div>
+  </div>
+</header>
+
+<main>
+  <div class="page-box">
+    <h1 class="title">Add topic</h1>
+
+    <nav>
+      <ol class="breadcrumbs">
+        <li class="breadcrumbs-item">
+          <a href="/">All categories</a>
+        </li>
+        <li class="breadcrumbs-item">
+          <a href="/{{ category.slug }}">{{ category.name }}</a>
+        </li>
+        <li class="breadcrumbs-item active">New topic</li>
+      </ol>
+    </nav>
+
+    {% if error is not null %}
+      <div class="error" style="color: #000000;
+    width: 100%;
+    margin-bottom: 24px;margin-top: -8px;">
+        {{ error }}
+      </div>
+    {% endif %}
+
+    <form action="/{{ category.slug }}/add-topic" method="post" enctype="multipart/form-data">
+      <div class="margin-bottom-16">
+        <input class="form-input" name="name" placeholder="Name of the topic" {% if name is not null %} value="{{ name }}" {% endif %} />
+      </div>
+      <div id="editor" style="display: none;height: 375px;" class="margin-bottom-16"></div>
+      <div class="margin-bottom-16">
+        {% if content is not null %}
+          <textarea class="form-input" name="content" rows="9" placeholder="Content">{{ content }}</textarea>
+        {% else %}
+          <textarea class="form-input" name="content" rows="9" placeholder="Content"></textarea>
+        {% endif %}
+      </div>
+      <div>
+        <input type="file" name="images[]" multiple />
+      </div>
+      <button class="form-button" type="submit">Add topic</button>
+    </form>
+  </div>
+</main>
+<script src="/assets/quill/quill.js"></script>
+<script>
+  var textarea = document.querySelector('textarea[name=content]');
+  textarea.style.display = 'none';
+
+  document.querySelector('#editor').style.display = 'block';
+
+  var quill = new Quill('#editor', {
+    modules: {
+      toolbar: [
+        [{ header: [1, 2, 3, false] }],
+        ['bold', 'italic', 'underline'],
+        ['code-block']
+      ]
+    },
+    placeholder: 'Content',
+    theme: 'snow'
+  });
+
+  var form = document.querySelector('form');
+  form.onsubmit = function() {
+    textarea.value = document.querySelector('.ql-editor').innerHTML;
+  }
+</script>
+</body>
+</html>

app/Forum/Topic/Views/edit.volt

@@ -0,0 +1,137 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <title>{{ appName }}</title>
+  <link rel="stylesheet" href="/assets/css/material-icons.css">
+  <link rel="stylesheet" href="/assets/css/shared.css">
+  <link rel="stylesheet" href="/assets/css/header.css">
+
+  <link rel="stylesheet" href="/assets/css/breadcrumbs.css">
+  <link rel="stylesheet" href="/assets/css/form.css">
+  <link rel="stylesheet" href="/assets/css/clickable-list.css">
+
+  <link rel="stylesheet" href="/assets/css/pages/add-category.css">
+
+  <link rel="stylesheet" href="/assets/quill/quill.snow.css">
+</head>
+<body>
+
+<header>
+  <div class="page-box header-main">
+    <div class="header-logo">
+      <img src="/assets/img/logo.svg">
+    </div>
+    {% if user is not null %}
+      <div class="username">
+        <span>{{ user.name }}</span>
+        <span class="material-icons-outlined">account_box</span>
+      </div>
+    {% endif %}
+  </div>
+
+  <div class="page-box header-menu">
+    <div>
+      <span class="margin-right-8 text-primary">Topics</span>
+      {% if userAccess.canManageUsers() %}
+        <a class="margin-right-8 text-gray" href="/users">Users</a>
+      {% endif %}
+      {% if user is null %}
+        <a class="text-gray" href="/login">Login</a>
+      {% else %}
+        <a class="text-gray" href="/logout">Logout</a>
+      {% endif %}
+    </div>
+  </div>
+</header>
+
+<main>
+  <div class="page-box">
+    <h1 class="title">Edit topic</h1>
+
+    <nav>
+      <ol class="breadcrumbs">
+        <li class="breadcrumbs-item">
+          <a href="/">All categories</a>
+        </li>
+        <li class="breadcrumbs-item">
+          <a href="/{{ category.slug }}">{{ category.name }}</a>
+        </li>
+        <li class="breadcrumbs-item">
+          <a href="/{{ category.slug }}/{{ topic.slug }}">{{ topic.name }}</a>
+        </li>
+        <li class="breadcrumbs-item active">Edit</li>
+      </ol>
+    </nav>
+
+    {% if error is not null %}
+      <div class="error" style="color: #000000;
+    width: 100%;
+    margin-bottom: 24px;margin-top: -8px;">
+        {{ error }}
+      </div>
+    {% endif %}
+
+    <form action="/topics/{{ topic.id }}" method="post" enctype="multipart/form-data">
+      <div class="margin-bottom-16">
+        <input class="form-input" name="name" placeholder="Name of the topic" value="{{ name is not null ? name : topic.name }}" />
+      </div>
+      <div id="editor" style="display: none;height: 375px;" class="margin-bottom-16">
+        {{ content is not null ? content : topic.content }}
+      </div>
+      <div class="margin-bottom-16">
+        <textarea class="form-input" name="content" rows="9" placeholder="Content">{{ content is not null ? content : topic.content }}</textarea>
+      </div>
+      <div>
+        <input type="file" name="images[]" multiple />
+      </div>
+      <div style="display: flex; justify-content: space-between;">
+        <button class="form-button" type="submit">Update</button>
+        {% if topicAccess.canDelete(topic.category_id, topic.created_by) %}
+          <a href="/topics/{{ topic.id }}/delete" class="form-button">
+            <span class="icon material-icons" style="margin-right: 4px">delete</span>
+            Delete topic
+          </a>
+        {% endif %}
+      </div>
+    </form>
+
+    <div class="clickable-list margin-top-24 margin-bottom-32">
+      {% for image in images %}
+        <div class="clickable-list-item">
+          <div>
+            <a href="/images/{{ image.id }}" target="_blank">
+              <img style="max-width: 160px;max-height: 160px;" src="{{ image.getImageBase64Content() }}">
+            </a>
+          </div>
+          <a href="/files/{{ image.id }}/delete?redirect_to=/topics/{{ topic.id }}" class="icon material-icons">delete</a>
+        </div>
+      {% endfor %}
+    </div>
+  </div>
+</main>
+<script src="/assets/quill/quill.js"></script>
+<script>
+  var textarea = document.querySelector('textarea[name=content]');
+  textarea.style.display = 'none';
+
+  document.querySelector('#editor').style.display = 'block';
+
+  var quill = new Quill('#editor', {
+    modules: {
+      toolbar: [
+        [{ header: [1, 2, 3, false] }],
+        ['bold', 'italic', 'underline'],
+        ['code-block']
+      ]
+    },
+    placeholder: 'Content',
+    theme: 'snow'
+  });
+
+  var form = document.querySelector('form');
+  form.onsubmit = function() {
+    textarea.value = document.querySelector('.ql-editor').innerHTML;
+  }
+</script>
+</body>
+</html>

app/Forum/Topic/Views/show.volt

@@ -0,0 +1,191 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <title>{{ appName }}</title>
+  <link rel="stylesheet" href="/assets/css/material-icons.css">
+  <link rel="stylesheet" href="/assets/css/shared.css">
+  <link rel="stylesheet" href="/assets/css/header.css">
+
+  <link rel="stylesheet" href="/assets/css/breadcrumbs.css">
+  <link rel="stylesheet" href="/assets/css/pagination.css">
+  <link rel="stylesheet" href="/assets/css/form.css">
+
+  <link rel="stylesheet" href="/assets/css/pages/topic.css">
+</head>
+<body>
+
+  <section class="main-section">
+    <header>
+      <div class="page-box header-main">
+        <div class="header-logo">
+          <img src="/assets/img/logo.svg">
+        </div>
+        {% if user is not null %}
+          <div class="username">
+            <span>{{ user.name }}</span>
+            <span class="material-icons-outlined">account_box</span>
+          </div>
+        {% endif %}
+      </div>
+
+      <div class="page-box header-menu">
+        <div>
+          <span class="margin-right-8 text-primary">Topics</span>
+          {% if userAccess.canManageUsers() %}
+            <a class="margin-right-8 text-gray" href="/users">Users</a>
+          {% endif %}
+          {% if user is null %}
+            <a class="text-gray" href="/login">Login</a>
+          {% else %}
+            <a class="text-gray" href="/logout">Logout</a>
+          {% endif %}
+        </div>
+      </div>
+    </header>
+
+    <main>
+      <div class="page-box">
+        <div class="author">
+          <div>
+            <span class="icon material-icons-outlined">account_box</span>
+            <span>{{ topic['author_name'] }}</span>
+          </div>
+        </div>
+
+        <h1 class="title">
+          <span>{{ topic['name'] }}</span>
+          {% if topicAccess.canChange(topic['category_id'], topic['author_id']) %}
+            <a href="/topics/{{ topic['id'] }}" class="icon material-icons">edit</a>
+          {% endif %}
+        </h1>
+
+        <nav>
+          <ol class="breadcrumbs">
+            <li class="breadcrumbs-item">
+              <a href="/">All categories</a>
+            </li>
+            <li class="breadcrumbs-item">
+              <a href="/{{ category['slug'] }}">{{ category['name'] }}</a>
+            </li>
+            <li class="breadcrumbs-item active">{{ topic['name'] }}</li>
+          </ol>
+        </nav>
+
+        {% if images|length > 0 %}
+          <div class="margin-bottom-16">
+            {% for image in images %}
+              <a href="/images/{{ image.id }}" target="_blank">
+                <img style="max-width: 160px;max-height: 160px;" src="/images/{{ image.id }}">
+              </a>
+            {% endfor %}
+          </div>
+        {% endif %}
+
+        <div class="content">{{ topic['content'] }}</div>
+
+      </div>
+    </main>
+
+    {% if comments|length > 0 %}
+      <section class="comments-section">
+        <div class="page-box">
+          <div>
+            <div class="secondary-title">{{ topic['comments_count'] }} {{ topic['comments_count'] == 1 ? 'Comment' : 'Comments' }}</div>
+          </div>
+
+          <div>
+            {% for comment in comments %}
+              <div class="comment">
+                <div class="comment-author">
+                  <span class="icon material-icons-outlined">account_box</span>
+                  <span>{{ comment['author_name'] }}</span>
+                </div>
+
+                {% if comment['reply_to_content'] is not null %}
+                  <div style="padding-left: 4px;
+    border-left: 2px solid #6d757d;
+    margin-bottom: 4px;
+    margin-left: 4px;
+    color: #6d757d;
+    font-size: 13px;">
+                    {{ comment['reply_to_content'] }}
+                  </div>
+                {% endif %}
+
+                {% if commentImages[comment['id']] is not null %}
+                  <div style="margin-top: 8px;margin-bottom: 8px;">
+                    {% for imageId in commentImages[comment['id']] %}
+                      <a href="/images/{{ imageId }}" target="_blank">
+                        <img style="max-width: 90px;max-height: 90px;" src="/images/{{ imageId }}">
+                      </a>
+                    {% endfor %}
+                  </div>
+                {% endif %}
+
+                <div class="comment-content">
+                  {{ comment['content'] }}
+                </div>
+
+                <div class="comment-actions">
+                  <a href="/{{ category['slug'] }}/{{ topic['slug'] }}/add-comment?reply_to={{ comment['id'] }}">
+                    <span class="icon material-icons">reply</span>
+                    <span class="comment-action-text">Reply</span>
+                  </a>
+
+                  {% if commentAccess.canChange(category['id'], comment['author_id']) %}
+                    <a href="/comments/{{ comment['id'] }}">
+                      <span class="icon material-icons">edit</span>
+                      <span class="comment-action-text">Edit</span>
+                    </a>
+                  {% endif %}
+
+                  {% if commentAccess.canDelete(category['id'], comment['author_id']) %}
+                    <a href="/comments/{{ comment['id'] }}/delete">
+                      <span class="icon material-icons">delete</span>
+                      <span class="comment-action-text">Delete</span>
+                    </a>
+                  {% endif %}
+                </div>
+              </div>
+            {% endfor %}
+          </div>
+
+          {% if pages > 1 %}
+            <div class="pagination">
+              <span>{{ page }} of {{ pages }} pages</span>
+              <div>
+                {% if page > 2 %}
+                  <a class="pagination-action" href="/{{ category['slug'] }}/{{ topic['slug'] }}?page=1">First page</a>
+                {% endif %}
+                {% if page > 1 %}
+                  <a class="pagination-action" href="/{{ category['slug'] }}/{{ topic['slug'] }}?page={{ page - 1 }}">Back</a>
+                {% endif %}
+                {% if page < pages %}
+                  <a class="pagination-action" href="/{{ category['slug'] }}/{{ topic['slug'] }}?page={{ page + 1 }}">Next</a>
+                {% endif %}
+                {% if page < pages and (pages - page) > 1 %}
+                  <a class="pagination-action" href="/{{ category['slug'] }}/{{ topic['slug'] }}?page={{ pages }}">Last page</a>
+                {% endif %}
+              </div>
+            </div>
+          {% endif %}
+        </div>
+      </section>
+    {% endif %}
+  </section>
+
+  <section class="add-comment-section">
+    <form class="page-box" method="post" action="/{{ category['slug'] }}/{{ topic['slug'] }}/add-comment" enctype="multipart/form-data">
+      <div class="secondary-title">Add comment</div>
+      <div>
+        <textarea class="form-input" rows="3" name="content" required placeholder="Type your comment here..."></textarea>
+      </div>
+      <div style="margin-top: 8px;">
+        <input name="images[]" type="file" multiple />
+      </div>
+      <button class="form-button" type="submit">Add comment</button>
+    </form>
+  </section>
+
+</body>
+</html>

app/Forum/Topic/config.php

@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+return [
+    'excluding_slugs' => [
+        'add-topic',
+    ],
+];

app/Forum/Topic/routes.php

@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+return [
+    'topic:show' => [
+        'pattern' => '/{categorySlug}/{slug}',
+        'paths' => [
+            'namespace' => 'App\Forum\Topic\Controllers',
+            'controller' => 'show',
+            'action' => 'main',
+        ],
+        'httpMethods' => ['GET'],
+    ],
+    'topic:add' => [
+        'pattern' => '/{categorySlug}/add-topic',
+        'paths' => [
+            'namespace' => 'App\Forum\Topic\Controllers',
+            'controller' => 'add',
+            'action' => 'main',
+        ],
+        'httpMethods' => ['GET', 'POST'],
+    ],
+    'topic:delete' => [
+        'pattern' => '/topics/{id}/delete',
+        'paths' => [
+            'namespace' => 'App\Forum\Topic\Controllers',
+            'controller' => 'delete',
+            'action' => 'main',
+        ],
+        'httpMethods' => ['GET'],
+    ],
+    'topic:edit' => [
+        'pattern' => '/topics/{id}',
+        'paths' => [
+            'namespace' => 'App\Forum\Topic\Controllers',
+            'controller' => 'edit',
+            'action' => 'main',
+        ],
+        'httpMethods' => ['GET', 'POST'],
+    ],
+];

app/SharedKernel/Controllers/ModuleViewRender.php

@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\SharedKernel\Controllers;
+
+use App\SharedKernel\StringConverter;
+
+trait ModuleViewRender
+{
+    public function renderView(array $vars = []): void
+    {
+        $appDir = str_replace(
+            StringConverter::classNameToDir(ModuleViewRender::class),
+            '',
+            __DIR__
+        );
+
+        $classNameExploded = explode('\\', get_called_class());
+        $viewName = strtolower(str_replace('Controller', '', end($classNameExploded)));
+
+        echo $this->view->render(
+            $appDir . StringConverter::classNameToDir(get_called_class()) . '/../Views/' . $viewName,
+            $vars
+        );
+    }
+}

app/SharedKernel/Controllers/Pagination.php

@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\SharedKernel\Controllers;
+
+trait Pagination
+{
+    public function getCurrentPage(): int
+    {
+        return (int) $this->request->getQuery('page', 'int', 1);
+    }
+
+    public function getSkipRowsNumber(int $rowsPerPage): int
+    {
+        return ($this->getCurrentPage() - 1) * $rowsPerPage;
+    }
+
+    public function getTotalPages(int $rowsTotal, int $rowsPerPage): int
+    {
+        return (int) ceil($rowsTotal / $rowsPerPage);
+    }
+}

app/SharedKernel/Controllers/Validation.php

@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\SharedKernel\Controllers;
+
+trait Validation
+{
+    /**
+     * @throws \InvalidArgumentException
+     */
+    public function validatePostRequest(array $rules): void
+    {
+        (new \App\SharedKernel\Http\Validation($rules))->validate($_POST);
+    }
+}

app/SharedKernel/Exceptions/AccessDeniedException.php

@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\SharedKernel\Exceptions;
+
+abstract class AccessDeniedException extends \DomainException
+{
+
+}

app/SharedKernel/Exceptions/NotFoundException.php

@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\SharedKernel\Exceptions;
+
+abstract class NotFoundException extends \DomainException
+{
+
+}

app/SharedKernel/File/Controllers/DeleteController.php

@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\SharedKernel\File\Controllers;
+
+use App\SharedKernel\File\Models\FileRepository;
+
+final class DeleteController extends \Phalcon\Mvc\Controller
+{
+    public function mainAction($id): void
+    {
+        (new FileRepository())->get($id)->delete();
+
+        $this->response->redirect($_GET['redirect_to']);
+    }
+}

app/SharedKernel/File/Controllers/ImagePreviewController.php

@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\SharedKernel\File\Controllers;
+
+use App\SharedKernel\File\Models\FileRepository;
+
+final class ImagePreviewController extends \Phalcon\Mvc\Controller
+{
+    public function mainAction($id): void
+    {
+        $file = (new FileRepository())->get($id);
+
+        header('Cache-Control: No-Store');
+        header('Content-Type:' . $file->mime_type);
+        header('Content-Length: ' . filesize($file->placement));
+        readfile($file->placement);
+    }
+}

app/SharedKernel/File/Models/File.php

@@ -0,0 +1,87 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\SharedKernel\File\Models;
+
+final class File extends \Phalcon\Mvc\Model
+{
+    public function initialize(): void
+    {
+        $this->setSource('files');
+    }
+
+    public static function addForForumTopic($id, $forumTopicId, string $tmpName, string $originalName): void
+    {
+        $mimeType = self::extractMimeType($tmpName);
+        $placement = self::getConfig()['files_dir'] . '/' . $id;
+
+        $file = new File([
+            'id' => $id,
+            'name' => $originalName,
+            'mime_type' => $mimeType,
+            'placement' => $placement,
+            'created_at' => (new \DateTime('now'))->format('Y-m-d H:i:s'),
+            'relation_table' => 'forum_topics',
+            'relation_id' => $forumTopicId,
+        ]);
+
+        move_uploaded_file($tmpName, $placement);
+
+        $file->save();
+    }
+
+    public static function addForForumComment($id, $forumCommentId, string $tmpName, string $originalName): void
+    {
+        $mimeType = self::extractMimeType($tmpName);
+        $placement = self::getConfig()['files_dir'] . '/' . $id;
+
+        $file = new File([
+            'id' => $id,
+            'name' => $originalName,
+            'mime_type' => $mimeType,
+            'placement' => $placement,
+            'created_at' => (new \DateTime('now'))->format('Y-m-d H:i:s'),
+            'relation_table' => 'forum_comments',
+            'relation_id' => $forumCommentId,
+        ]);
+
+        move_uploaded_file($tmpName, $placement);
+
+        $file->save();
+    }
+
+    private static function getConfig(): array
+    {
+        return include __DIR__ . '/../config.php';
+    }
+
+    public function delete(): void
+    {
+        unlink($this->placement);
+
+        parent::delete();
+    }
+
+    public function getImageBase64Content(): string
+    {
+        if (!self::isImageMimeType($this->mime_type)) {
+            return '';
+        }
+
+        $data = file_get_contents($this->placement);
+        $type = pathinfo($this->placement, PATHINFO_EXTENSION);
+
+        return 'data:image/' . $type . ';base64,' . base64_encode($data);
+    }
+
+    public static function isImageMimeType(string $mimeType): bool
+    {
+        return str_contains($mimeType, 'image/');
+    }
+
+    public static function extractMimeType(string $placement): string
+    {
+        return (new \finfo(FILEINFO_MIME_TYPE))->file($placement);
+    }
+}

app/SharedKernel/File/Models/FileNotFound.php

@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\SharedKernel\File\Models;
+
+use App\SharedKernel\Exceptions\NotFoundException;
+
+final class FileNotFound extends NotFoundException
+{
+    public function __construct()
+    {
+        parent::__construct('File not found');
+    }
+}

app/SharedKernel/File/Models/FileReadRepository.php

@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\SharedKernel\File\Models;
+
+final class FileReadRepository
+{
+    public function findByForumTopicId($id): array
+    {
+        $connection = \Phalcon\DI::getDefault()->getShared('db');
+
+        $sql = "SELECT * FROM files WHERE relation_table = 'forum_topics' AND relation_id = '$id'";
+
+        $query = $connection->query($sql);
+        $query->setFetchMode(\Phalcon\Db::FETCH_ASSOC);
+
+        return $query->fetch();
+    }
+
+    public function findByForumCommentId($id): array
+    {
+        $connection = \Phalcon\DI::getDefault()->getShared('db');
+
+        $sql = "SELECT * FROM files WHERE relation_table = 'forum_comments' AND relation_id = '$id'";
+
+        $query = $connection->query($sql);
+        $query->setFetchMode(\Phalcon\Db::FETCH_ASSOC);
+
+        return $query->fetch();
+    }
+}

app/SharedKernel/File/Models/FileRepository.php

@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\SharedKernel\File\Models;
+
+final class FileRepository
+{
+    public function get($id): File
+    {
+        $file = File::findFirst("id = '$id'");
+
+        if ($file === false) {
+            throw new FileNotFound();
+        }
+
+        return $file;
+    }
+
+    public function findByForumTopicId($id)
+    {
+        return File::find("relation_table = 'forum_topics' AND relation_id = '$id'");
+    }
+
+    public function findByForumCommentId($id)
+    {
+        return File::find("relation_table = 'forum_comments' AND relation_id = '$id'");
+    }
+
+    public function findByForumCommentsIds(array $ids)
+    {
+        $idsRow = '\'' . implode('\', \'', $ids) . '\'';
+
+        return File::find("relation_table = 'forum_comments' AND relation_id IN ($idsRow)");
+    }
+}

app/SharedKernel/File/config.php

@@ -0,0 +1,5 @@
+<?php
+
+return [
+    'files_dir' => __DIR__ . '/../../../storage/files',
+];

app/SharedKernel/File/routes.php

@@ -0,0 +1,24 @@
+<?php
+
+declare(strict_types=1);
+
+return [
+    'file:image-preview' => [
+        'pattern' => '/images/{id}',
+        'paths' => [
+            'namespace' => 'App\SharedKernel\File\Controllers',
+            'controller' => 'image_preview',
+            'action' => 'main',
+        ],
+        'httpMethods' => ['GET'],
+    ],
+    'file:delete' => [
+        'pattern' => '/files/{id}/delete',
+        'paths' => [
+            'namespace' => 'App\SharedKernel\File\Controllers',
+            'controller' => 'delete',
+            'action' => 'main',
+        ],
+        'httpMethods' => ['GET'],
+    ],
+];

app/SharedKernel/Http/RequestFilesNormalizer.php

@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\SharedKernel\Http;
+
+final class RequestFilesNormalizer
+{
+    public static function normalize(array $requestFiles): array
+    {
+        $normalizedFiles = [];
+        $count = count($requestFiles['name']);
+        $keys = array_keys($requestFiles);
+
+        for ($i = 0; $i < $count; $i++) {
+            foreach ($keys as $key) {
+                $normalizedFiles[$i][$key] = $requestFiles[$key][$i];
+            }
+        }
+
+        return $normalizedFiles;
+    }
+}

app/SharedKernel/Http/Validation.php

@@ -0,0 +1,127 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\SharedKernel\Http;
+
+use App\SharedKernel\StringConverter;
+use Phalcon\Validation\Validator\PresenceOf;
+use Phalcon\Validation\Validator\Callback;
+use Phalcon\Validation\Message;
+
+/**
+ * @method validate($data)
+ */
+class Validation extends \Phalcon\Validation
+{
+    private $rules;
+
+    public function __construct(array $rules)
+    {
+        $this->rules = $rules;
+        parent::__construct();
+    }
+
+    public function initialize()
+    {
+        foreach ($this->rules as $argument => $rules) {
+            $rules = explode('|', $rules);
+
+            foreach ($rules as $rule) {
+                list($rule, $value) = explode(':', $rule);
+
+                switch ($rule) {
+                    case 'required':
+                        $this->add(
+                            $argument,
+                            new PresenceOf(
+                                [
+                                    'message' => new Message(
+                                        sprintf(
+                                            '%s is required',
+                                            StringConverter::snakeCaseToReadable($argument, true)
+                                        )
+                                    ),
+                                ]
+                            )
+                        );
+                        break;
+                    case 'between':
+                        $values = explode(',', $value);
+                        $this->add(
+                            $argument,
+                            new Callback([
+                                'callback' => function (array $data) use ($argument, $values): bool {
+                                    if (!isset($data[$argument])) {
+                                        return false;
+                                    }
+                                    return in_array((int) $data[$argument], range($values[0], $values[1]));
+                                },
+                                'message' => new Message(
+                                    sprintf(
+                                        '%s must be between %d and %d',
+                                        StringConverter::snakeCaseToReadable($argument, true),
+                                        $values[0],
+                                        $values[1]
+                                    )
+                                ),
+                            ])
+                        );
+                        break;
+                    case 'equal':
+                        $this->add(
+                            $argument,
+                            new Callback([
+                                'callback' => function (array $data) use ($argument, $value): bool {
+                                    if (!isset($data[$argument])) {
+                                        return false;
+                                    }
+                                    return $data[$argument] === $value;
+                                },
+                                'message' => new Message(
+                                    sprintf(
+                                        '%s must be only %s',
+                                        StringConverter::snakeCaseToReadable($argument, true),
+                                        $value
+                                    )
+                                ),
+                            ])
+                        );
+                        break;
+                    case 'length_between':
+                        $values = explode(',', $value);
+                        $this->add(
+                            $argument,
+                            new Callback([
+                                'callback' => function (array $data) use ($argument, $values): bool {
+                                    if (!isset($data[$argument])) {
+                                        return false;
+                                    }
+                                    $length = strlen(trim($data[$argument]));
+                                    return $length >= $values[0] && $length <= $values[1];
+                                },
+                                'message' => new Message(
+                                    sprintf(
+                                        'Length of %s must be between %d and %d symbols',
+                                        StringConverter::snakeCaseToReadable($argument),
+                                        $values[0],
+                                        $values[1]
+                                    )
+                                ),
+                            ])
+                        );
+                        break;
+                }
+            }
+        }
+    }
+
+    public function afterValidation($data, $entity, $messages)
+    {
+        if (count($messages)) {
+            foreach ($messages as $message) {
+                throw new \InvalidArgumentException((string) $message);
+            }
+        }
+    }
+}

app/SharedKernel/RandomStringGenerator.php

@@ -0,0 +1,26 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\SharedKernel;
+
+final class RandomStringGenerator
+{
+    private const SYMBOLS_COLLECTION = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
+    private const NUMBERS_COLLECTION = '0123456789';
+
+    public static function generate(int $length): string
+    {
+        $input = self::NUMBERS_COLLECTION . self::SYMBOLS_COLLECTION;
+
+        $inputLength = strlen($input);
+        $randomString = '';
+
+        for ($i = 0; $i < $length; $i++) {
+            $randomCharacter = $input[rand(0, $inputLength - 1)];
+            $randomString .= $randomCharacter;
+        }
+
+        return $randomString;
+    }
+}

app/SharedKernel/StringConverter.php

@@ -0,0 +1,57 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\SharedKernel;
+
+final class StringConverter
+{
+    public static function snakeCaseToCamelCase(string $value): string
+    {
+        $result = str_replace(' ', '', ucwords(str_replace('_', ' ', $value)));
+        $result[0] = strtolower($result[0]);
+
+        return $result;
+    }
+
+    public static function snakeCaseToReadable(string $value, bool $upFirst = false): string
+    {
+        $result = str_replace('_', ' ', $value);
+
+        return $upFirst ? ucfirst($result) : $result;
+    }
+
+    public static function readableToSlug(string $value): string
+    {
+        $divider = '-';
+
+        $value = preg_replace('~[^\pL\d]+~u', $divider, $value);
+        $value = iconv('utf-8', 'us-ascii//TRANSLIT', $value);
+        $value = preg_replace('~[^-\w]+~', '', $value);
+        $value = trim($value, $divider);
+        $value = preg_replace('~-+~', $divider, $value);
+
+        return strtolower($value);
+    }
+
+    public static function classNameToDir(string $value): string
+    {
+        $classNameExploded = explode('\\', $value);
+
+        return substr(
+            lcfirst(
+                str_replace(
+                    '\\',
+                    '/',
+                    str_replace(
+                        end($classNameExploded),
+                        '',
+                        $value
+                    )
+                )
+            ),
+            0,
+            -1
+        );
+    }
+}

app/SharedKernel/Structs/Enum.php

@@ -0,0 +1,24 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\SharedKernel\Structs;
+
+use App\SharedKernel\StringConverter;
+
+abstract class Enum extends ValueObject
+{
+    /**
+     * @throws \InvalidArgumentException
+     */
+    public static function fromValue(string $value): self
+    {
+        $methodName = StringConverter::snakeCaseToCamelCase($value);
+
+        if (!method_exists(static::class, $methodName)) {
+            throw new \InvalidArgumentException(sprintf('Passed value \'%s\' doesn\'t allowed here', $value));
+        }
+
+        return static::$methodName();
+    }
+}

app/SharedKernel/Structs/ValueObject.php

@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\SharedKernel\Structs;
+
+abstract class ValueObject implements \Stringable
+{
+    public $value;
+
+    public function __construct($value)
+    {
+        $this->value = $value;
+    }
+
+    public function __toString(): string
+    {
+        return (string) $this->value;
+    }
+}

app/SharedKernel/Tasks/RunMigrationTask.php

@@ -0,0 +1,53 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\SharedKernel\Tasks;
+
+final class RunMigrationTask extends \Phalcon\Cli\Task
+{
+    public function mainAction()
+    {
+        $migrationsDirectory = __DIR__ . '/../../../migrations';
+        $this->createMigrationsTableIfNotExist();
+
+        $candidates = array_map(
+            static function (string $file): int {
+                return (int) explode('.', $file)[0];
+            },
+            array_diff(scandir($migrationsDirectory), ['..', '.'])
+        );
+
+        sort($candidates);
+
+        $last = $this->getLastExecuted();
+        $counter = 0;
+
+        foreach ($candidates as $candidate) {
+            if ($candidate > $last) {
+                $filename = $migrationsDirectory . '/' . $candidate . '.sql';
+                $this->db->execute(file_get_contents($filename));
+                $this->setLastExecuted($candidate);
+                $counter++;
+            }
+        }
+
+        echo sprintf('Migrated %d', $counter);
+        echo PHP_EOL;
+    }
+
+    private function createMigrationsTableIfNotExist()
+    {
+        $this->db->execute('CREATE TABLE IF NOT EXISTS migrations (version BIGINT NOT NULL, PRIMARY KEY(version))');
+    }
+
+    private function getLastExecuted(): int
+    {
+        return (int) $this->db->fetchColumn('SELECT version FROM migrations ORDER BY version DESC LIMIT 1');
+    }
+
+    private function setLastExecuted(int $version): void
+    {
+        $this->db->execute(sprintf('INSERT INTO migrations VALUES (%d)', $version));
+    }
+}

app/SharedKernel/TimeSorting.php

@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\SharedKernel;
+
+use App\SharedKernel\Structs\Enum;
+
+final class TimeSorting extends Enum
+{
+    public static function newest(): self
+    {
+        return new self('newest');
+    }
+
+    public static function oldest(): self
+    {
+        return new self('oldest');
+    }
+}

app/SharedKernel/Views/error.volt

@@ -0,0 +1,14 @@
+<html lang="en">
+<head>
+  <title>{{ appName }}</title>
+  <link rel="stylesheet" href="/assets/css/bootstrap.min.css">
+</head>
+<body>
+<div class="container" style="justify-content: center;display: flex;height: 100vh;align-items: center;text-align: center;">
+  <div>
+    <h1>{{ code }}</h1>
+    <h2>{{ message }}</h2>
+  </div>
+</div>
+</body>
+</html>

app/SharedKernel/Views/partials/header.volt

@@ -0,0 +1,25 @@
+<header>
+  <div class="page-box header-main">
+    <div class="header-logo">
+      <img src="/assets/img/logo.svg">
+    </div>
+    {% if user is not null %}
+      <div class="username">
+        <span>{{ user.name }}</span>
+        <span class="material-icons-outlined">account_box</span>
+      </div>
+    {% endif %}
+  </div>
+
+  <div class="page-box header-menu">
+    <div>
+      <a class="margin-right-8 text-gray" href="/">Topics</a>
+      <span class="margin-right-8 text-primary">Users</span>
+      {% if user is null %}
+        <a class="text-gray" href="/login">Login</a>
+      {% else %}
+        <a class="text-gray" href="/logout">Logout</a>
+      {% endif %}
+    </div>
+  </div>
+</header>

app/User/Console/CreateFirstAdminTask.php

@@ -0,0 +1,39 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\User\Console;
+
+use App\Access\Models\Role;
+use App\User\Models\User;
+use App\User\Models\UserNotFound;
+use App\User\Models\UserRepository;
+use Ramsey\Uuid\Uuid;
+
+final class CreateFirstAdminTask extends \Phalcon\Cli\Task
+{
+    public function mainAction(): void
+    {
+        try {
+            $this->getUserRepository()->getByName($this->config['user']['admin_name']);
+
+            echo 'Default admin user already exists' . PHP_EOL;
+        } catch (UserNotFound $exception) {
+            User::add(
+                Uuid::uuid4(),
+                $this->config['user']['admin_name'],
+                $this->config['user']['admin_password'],
+                Role::admin()
+            );
+
+            echo 'Admin user created' . PHP_EOL;
+            echo 'Name: ' . $this->config['user']['admin_name'] . PHP_EOL;
+            echo 'Password: ' . $this->config['user']['admin_password'] . PHP_EOL;
+        }
+    }
+
+    private function getUserRepository(): UserRepository
+    {
+        return new UserRepository();
+    }
+}

app/User/Controllers/AddController.php

@@ -0,0 +1,67 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\User\Controllers;
+
+use App\Access\Models\AccessChecker\User\AccessChecker;
+use App\Access\Models\Forbidden;
+use App\Access\Models\Role;
+use App\Auth\Models\Auth;
+use App\SharedKernel\Controllers\ModuleViewRender;
+use App\SharedKernel\Http\Validation;
+use App\User\Models\User;
+use Ramsey\Uuid\Uuid;
+
+final class AddController extends \Phalcon\Mvc\Controller
+{
+    use ModuleViewRender;
+
+    public function mainAction(): void
+    {
+        if (!$this->getAccessChecker()->canManageUsers()) {
+            throw new Forbidden();
+        }
+
+        if ($this->request->isPost()) {
+            try {
+                $validation = new Validation([
+                    'name' => 'required|length_between:3,36',
+                    'password' => 'required|length_between:6,36',
+                ]);
+
+                $validation->validate($_POST);
+
+                $user = $this->getAuth()->getUserFromSession();
+
+                $addingUserId = Uuid::uuid4();
+
+                User::add(
+                    $addingUserId,
+                    $_POST['name'],
+                    $_POST['password'],
+                    Role::user(),
+                    $user->id
+                );
+
+                $this->response->redirect('/users/' . $addingUserId);
+            } catch (\LogicException $e) {
+                $this->renderView(['error' => $e->getMessage(), 'name' => $_POST['name']]);
+
+                return;
+            }
+        }
+
+        $this->renderView();
+    }
+
+    private function getAuth(): Auth
+    {
+        return new Auth();
+    }
+
+    private function getAccessChecker(): AccessChecker
+    {
+        return new AccessChecker();
+    }
+}

app/User/Controllers/DeleteController.php

@@ -0,0 +1,34 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\User\Controllers;
+
+use App\Access\Models\AccessChecker\User\AccessChecker;
+use App\Access\Models\Forbidden;
+use App\User\Models\UserRepository;
+
+final class DeleteController extends \Phalcon\Mvc\Controller
+{
+    public function mainAction(string $id): void
+    {
+        if (!$this->getAccessChecker()->canManageUsers()) {
+            throw new Forbidden();
+        }
+
+        $user = $this->getUserRepository()->get($id);
+        $user->delete();
+
+        $this->response->redirect('/users');
+    }
+
+    private function getUserRepository(): UserRepository
+    {
+        return new UserRepository();
+    }
+
+    private function getAccessChecker(): AccessChecker
+    {
+        return new AccessChecker();
+    }
+}

app/User/Controllers/IndexController.php

@@ -0,0 +1,45 @@
+<?php
+
+namespace App\User\Controllers;
+
+use App\Access\Models\AccessChecker\User\AccessChecker;
+use App\Access\Models\Forbidden;
+use App\SharedKernel\Controllers\ModuleViewRender;
+use App\SharedKernel\Controllers\Pagination;
+use App\User\Models\UserRepository;
+
+final class IndexController extends \Phalcon\Mvc\Controller
+{
+    use ModuleViewRender;
+    use Pagination;
+
+    public function mainAction(): void
+    {
+        if (!$this->getAccessChecker()->canManageUsers()) {
+            throw new Forbidden();
+        }
+
+        $rowsPerPage = 10;
+
+        $users = $this->getUserRepository()->find(
+            $rowsPerPage,
+            $this->getSkipRowsNumber($rowsPerPage)
+        );
+
+        $this->renderView([
+            'users' => $users,
+            'page' => $this->getCurrentPage(),
+            'pages' => $this->getTotalPages($this->getUserRepository()->count(), $rowsPerPage),
+        ]);
+    }
+
+    private function getUserRepository(): UserRepository
+    {
+        return new UserRepository();
+    }
+
+    private function getAccessChecker(): AccessChecker
+    {
+        return new AccessChecker();
+    }
+}

app/User/Controllers/ShowController.php

@@ -0,0 +1,34 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\User\Controllers;
+
+use App\Access\Models\AccessChecker\User\AccessChecker;
+use App\Access\Models\Forbidden;
+use App\SharedKernel\Controllers\ModuleViewRender;
+use App\User\Models\UserRepository;
+
+final class ShowController extends \Phalcon\Mvc\Controller
+{
+    use ModuleViewRender;
+
+    public function mainAction(string $id): void
+    {
+        if (!$this->getAccessChecker()->canManageUsers()) {
+            throw new Forbidden();
+        }
+
+        $this->renderView(['user1' => $this->getUserRepository()->get($id)]);
+    }
+
+    private function getUserRepository(): UserRepository
+    {
+        return new UserRepository();
+    }
+
+    private function getAccessChecker(): AccessChecker
+    {
+        return new AccessChecker();
+    }
+}

app/User/Models/User.php

@@ -0,0 +1,46 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\User\Models;
+
+use App\Access\Models\Role;
+
+final class User extends \Phalcon\Mvc\Model
+{
+    public function initialize(): void
+    {
+        $this->setSource('users');
+    }
+
+    public static function add(
+        $id,
+        string $name,
+        string $password,
+        Role $role,
+        $userId = null
+    ): void {
+        if ((new UserRepository())->existByName($name)) {
+            throw new UserAlreadyExist();
+        }
+
+        $user = new self([
+            'id' => $id,
+            'name' => strtolower($name),
+            'password_hash' => hash('sha256', $password),
+            'role' => $role,
+            'created_at' => (new \DateTime('now'))->format('Y-m-d H:i:s'),
+            'created_by' => $userId,
+        ]);
+
+        $user->save();
+    }
+
+    public function assignRole(Role $role, $userId): void
+    {
+        $this->role = $role;
+        $this->updated_at = (new \DateTime('now'))->format('Y-m-d H:i:s');
+        $this->updated_by = $userId;
+        $this->save();
+    }
+}