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

namespace Sakura\Forum;

use Sakura\Utils;
use Sakura\Database;
use Sakura\User;
use Sakura\BBcode;
use Sakura\Config;
use Sakura\Net;

/**
 * Used to serve, create and update posts.
 * 
 * @package Sakura
 * @author Julian van de Groep <me@flash.moe>
 */
class Post
{
    /**
     * The ID of the post.
     * 
     * @var int
     */
    public $id = 0;

    /**
     * The id of the thread this post is a part of.
     * 
     * @var int
     */
    public $thread = 0;

    /**
     * The id of the forum this post is a part of.
     * 
     * @var int
     */
    public $forum = 0;

    /**
     * The User object of the poster.
     * 
     * @var User
     */
    public $poster = null;

    /**
     * The IP address from which this post was created.
     * 
     * @var string
     */
    public $ip = "";

    /**
     * The UNIX timestamp from when this post was created.
     * 
     * @var int
     */
    public $time = 0;

    /**
     * The subject of this post.
     * 
     * @var string
     */
    public $subject = "";

    /**
     * The raw contents of this post.
     * 
     * @var string
     */
    public $text = "";

    /**
     * The parsed contents of this post.
     * 
     * @var string
     */
    public $parsed = "";

    /**
     * The UNIX timestamp of the last time this post was edited.
     * 
     * @var int
     */
    public $editTime = 0;

    /**
     * The reason why this post was edited.
     * 
     * @var string
     */
    public $editReason = "";

    /**
     * The User object of the user that last edited this post.
     * 
     * @var User
     */
    public $editUser = null;

    /**
     * Constructor.
     * 
     * @param int $postId ID of the post that should be constructed.
     */
    public function __construct($postId)
    {
        // Attempt to get the database row
        $postRow = Database::fetch('posts', false, ['post_id' => [$postId, '=']]);
        
        // Assign data if a row was returned
        if ($postRow) {
            $this->id = $postRow['post_id'];
            $this->thread = $postRow['topic_id'];
            $this->forum = $postRow['forum_id'];
            $this->poster = User::construct($postRow['poster_id']);
            $this->ip = $postRow['poster_ip'];
            $this->time = $postRow['post_time'];
            $this->subject = $postRow['post_subject'];
            $this->text = $postRow['post_text'];
            $this->editTime = $postRow['post_edit_time'];
            $this->editReason = $postRow['post_edit_reason'];
            $this->editUser = User::construct($postRow['post_edit_user']);
        }

        // Parse the markup
        $this->parsed = BBcode::toHTML(htmlentities($this->text));
    }

    /**
     * Creating a new post.
     * 
     * @param string $subject The subject of the thread.
     * @param string $text The raw contents of the post.
     * @param User $poster The User object of the poster.
     * @param int $thread The ID of the thread this post is a reply to.
     * @param mixed $forum The forum this post is a reply in.
     * 
     * @return null|Post Either null, indicating a failure, or the Post object.
     */
    public static function create($subject, $text, User $poster, $thread = 0, $forum = 0)
    {
        // Check if the data meets the requirements
        if (strlen($subject) < Config::get('forum_title_min')
            || strlen($subject) > Config::get('forum_title_max')
            || strlen($text) < Config::get('forum_text_min')
            || strlen($text) > Config::get('forum_text_max')) {
            return null;
        }

        // If no thread is specified create a new one
        if ($thread) {
            $thread = new Thread($thread);
        } else {
            $thread = Thread::create($forum, $subject);
        }

        // Stop if the thread ID is 0
        if ($thread->id == 0) {
            return null;
        }

        // Insert the post
        Database::insert('posts', [
            'topic_id' => $thread->id,
            'forum_id' => $thread->forum,
            'poster_id' => $poster->id,
            'poster_ip' => Net::IP(),
            'post_time' => time(),
            'post_subject' => $subject,
            'post_text' => $text,
        ]);

        // Get post id
        $id = Database::lastInsertID();

        // Update the last post date
        $thread->lastUpdate();

        // Return the object
        return new Post($id);
    }

    /**
     * Commit the changes to the Database.
     * 
     * @return null|Post Either null, indicating a failure, or the Post object.
     */
    public function update()
    {
        // Check if the data meets the requirements
        if (strlen($this->subject) < Config::get('forum_title_min')
            || strlen($this->subject) > Config::get('forum_title_max')
            || strlen($this->text) < Config::get('forum_text_min')
            || strlen($this->text) > Config::get('forum_text_max')) {
            return null;
        }

        // Create a thread object
        $thread = new Thread($this->thread);

        // Update the post
        Database::update('posts', [
            [
                'topic_id' => $thread->id,
                'forum_id' => $thread->forum,
                'poster_id' => $this->poster->id,
                'poster_ip' => Net::pton(Net::IP()),
                'post_time' => $this->time,
                'post_subject' => $this->subject,
                'post_text' => $this->text,
                'post_edit_time' => $this->editTime,
                'post_edit_reason' => $this->editReason,
                'post_edit_user' => $this->editUser->id,
            ],
            [
                'post_id' => [$this->id, '='],
            ]
        ]);

        // Return a new post object
        return new Post($this->id);
    }
}