<?php
/**
 * Holds the forum object class.
 * @package Sakura
 */

namespace Sakura\Forum;

use Sakura\DB;
use Sakura\CurrentSession;

/**
 * Used to serve forums.
 * @package Sakura
 * @author Julian van de Groep <me@flash.moe>
 */
class Forum
{
    /**
     * The ID of the forum.
     * @var int
     */
    public $id = 0;

    /**
     * The order of the forum.
     * @var int
     */
    public $order = 0;

    /**
     * The name of the forum.
     * @var string
     */
    public $name = "Forum";

    /**
     * The description of the forum.
     * @var string
     */
    public $description = "";

    /**
     * The link of the forum (if the type is 2).
     * @var string
     */
    public $link = "";

    /**
     * The ID of the parent forum.
     * @var int
     */
    public $category = 0;

    /**
     * The type of forum.
     * @var int
     */
    public $type = 0;

    /**
     * The icon of this forum.
     * @var string
     */
    public $icon = "";

    /**
     * Amount of topics in this forum.
     * @var int
     */
    public $countTopics = 0;

    /**
     * Amount of posts in this forum.
     * @var int
     */
    public $countPosts = 0;

    /**
     * Id of the last post made in this forum.
     * @var int
     */
    public $lastPostId = 0;

    /**
     * Title of the last post made in this forum.
     * @var string
     */
    public $lastPostTitle = "";

    /**
     * Post time of the last post made in this forum.
     * @var int
     */
    public $lastPostTime = 0;

    /**
     * User id which last posted in this forum.
     * @var int
     */
    public $lastPostUserId = 0;

    /**
     * Username which last posted in this forum.
     * @var string
     */
    public $lastPostUsername = "";

    /**
     * Colour of user which last posted in this forum.
     * @var string
     */
    public $lastPostUserColour = "";

    /**
     * Holds the permission handler.
     * @var ForumPerms
     */
    public $perms;

    /**
     * A cached instance of the last post in this forum.
     * @var Post
     */
    private $lastPostCache = null;

    /**
     * Cached instances of the subforums.
     * @var array
     */
    private $forumsCache = [];

    /**
     * Cached instances of the topics in this forum.
     * @var array
     */
    private $topicsCache = [];

    /**
     * Constructor.
     * @param int $forumId
     */
    public function __construct(int $forumId = 0)
    {
        // Get the row from the database
        $forumRow = DB::table('forums')
            ->where('forum_id', $forumId)
            ->first();

        // Populate the variables
        if ($forumRow) {
            $this->id = intval($forumRow->forum_id);
            $this->order = intval($forumRow->forum_order);
            $this->name = $forumRow->forum_name;
            $this->description = $forumRow->forum_desc;
            $this->link = $forumRow->forum_link;
            $this->category = intval($forumRow->forum_category);
            $this->type = intval($forumRow->forum_type);
            $this->icon = $forumRow->forum_icon;
            $this->countTopics = intval($forumRow->forum_count_topics);
            $this->countPosts = intval($forumRow->forum_count_posts);
            $this->lastPostId = intval($forumRow->last_post_id);
            $this->lastPostTitle = $forumRow->last_post_title;
            $this->lastPostTime = intval($forumRow->last_post_time);
            $this->lastPostUserId = intval($forumRow->last_post_user_id);
            $this->lastPostUsername = $forumRow->last_post_username;
            $this->lastPostUserColour = $forumRow->last_post_user_colour;
        } elseif ($forumId !== 0) {
            $this->id = -1;
        }

        $this->perms = new ForumPerms($this, CurrentSession::$user);
    }

    /**
     * Gets all subforums of this forum.
     * @return array
     */
    public function forums(): array
    {
        // Check if forumsCache is populated
        if (!count($this->forumsCache)) {
            // Get all rows with the category id set to the forum id
            $forumRows = DB::table('forums')
                ->where('forum_category', $this->id)
                ->orderBy('forum_order')
                ->get(['forum_id']);

            // Create a storage array
            $forums = [];

            // Create new objects for each forum
            foreach ($forumRows as $forum) {
                $forums[$forum->forum_id] = new Forum($forum->forum_id);
            }

            $this->forumsCache = $forums;
        }

        return $this->forumsCache;
    }

    /**
     * Gets the topics in this forum.
     * @return array
     */
    public function topics(): array
    {
        // Check if topicsCache is populated
        if (!count($this->topicsCache)) {
            // Get all rows with the forum id for this forum
            $topicRows = DB::table('topics')
                ->where('forum_id', $this->id)
                ->orderBy('topic_type', 'desc')
                ->orderBy('topic_last_reply', 'desc')
                ->get(['topic_id']);

            // Create a storage array
            $topics = [];

            // Create new objects for each topic
            foreach ($topicRows as $topic) {
                $topics[$topic->topic_id] = new Topic($topic->topic_id);
            }

            $this->topicsCache = $topics;
        } else {
            $topics = $this->topicsCache;
        }

        // Return the topic objects
        return $topics;
    }

    /**
     * Increment counts.
     * @param bool $topic
     * @param int $amount_posts
     * @param int $amount_topics
     */
    public function incrementPostsCount(bool $topic = false, int $amount_posts = 1, int $amount_topics = 1): void
    {
        $this->countPosts = (int) DB::table('forums')
            ->where('forum_id', $this->id)
            ->increment('forum_count_posts', $amount_posts);

        if ($topic) {
            $this->countTopics = (int) DB::table('forums')
                ->where('forum_id', $this->id)
                ->increment('forum_count_topics', $amount_topics);
        }
    }

    /**
     * Decrement counts.
     * @param bool $topic
     * @param int $amount_posts
     * @param int $amount_topics
     */
    public function decrementPostsCount(bool $topic = false, int $amount_posts = 1, int $amount_topics = 1): void
    {
        $this->countPosts = (int) DB::table('forums')
            ->where('forum_id', $this->id)
            ->decrement('forum_count_posts', $amount_posts);

        if ($topic) {
            $this->countTopics = (int) DB::table('forums')
                ->where('forum_id', $this->id)
                ->decrement('forum_count_topics', $amount_topics);
        }
    }

    /**
     * Updates last post information for this forum.
     * @param Post $post
     */
    public function updateLastPost(Post $post = null): void
    {
        if ($post === null) {
            $post_id = DB::table('posts')
                ->where('forum_id', $this->id)
                ->orderBy('post_id', 'desc')
                ->take(1)
                ->value('post_id');

            $post = new Post($post_id);
        }

        DB::table('forums')
            ->where('forum_id', $this->id)
            ->update([
                'last_post_id' => $this->lastPostId = $post->id,
                'last_post_title' => $this->lastPostTitle = $post->subject,
                'last_post_time' => $this->lastPostTime = $post->time,
                'last_post_user_id' => $this->lastPostUserId = $post->poster->id,
                'last_post_username' => $this->lastPostUsername = $post->poster->username,
                'last_post_user_colour' => $this->lastPostUserColour = $post->poster->colour,
            ]);
    }

    /**
     * Checks if a user has read every post in the specified forum.
     * @param int $user
     * @return bool
     */
    public function unread(int $user): bool
    {
        // Return false if the user id is less than 1
        if ($user < 1) {
            return false;
        }

        // Check forums
        foreach ($this->forums() as $forum) {
            if ($forum->unread($user)) {
                return true;
            }
        }

        // Check each topic
        foreach ($this->topics() as $topic) {
            if ($topic->unread($user)) {
                return true;
            }
        }

        // Return false if negative
        return false;
    }

    /**
     * Update the read status of all topics in this forum at once.
     * @param int $user
     */
    public function trackUpdateAll(int $user): void
    {
        // Iterate over every forum
        foreach ($this->forums() as $forum) {
            // Update every forum
            $forum->trackUpdateAll($user);
        }

        // Iterate over every topic
        foreach ($this->topics() as $topic) {
            // Update every topic
            $topic->trackUpdate($user);
        }
    }
}