<?php

/**
 * Kunena Component
 *
 * @package       Kunena.Framework
 * @subpackage    Forum.Topic.User
 *
 * @copyright     Copyright (C) 2008 - @currentyear@ Kunena Team. All rights reserved.
 * @license       https://www.gnu.org/copyleft/gpl.html GNU/GPL
 * @link          https://www.kunena.org
 **/

namespace Kunena\Forum\Libraries\Forum\Topic\User;

\defined('_JEXEC') or die();

use Exception;
use Joomla\CMS\Factory;
use Joomla\Database\Exception\ExecutionFailureException;
use Kunena\Forum\Libraries\Error\KunenaError;
use Kunena\Forum\Libraries\Forum\Topic\KunenaTopic;
use Kunena\Forum\Libraries\User\KunenaUser;
use Kunena\Forum\Libraries\User\KunenaUserHelper;

/**
 * Kunena Forum Topic User Helper Class
 *
 * @since   Kunena 6.0
 */
abstract class KunenaTopicUserHelper
{
    /**
     * @var     array|KunenaTopicUser[]
     * @since   Kunena 6.0
     */
    protected static $_instances = [];

    /**
     * @var     array|KunenaTopicUser[]
     * @since   Kunena 6.0
     */
    protected static $_topics = [];

    /**
     * @var     boolean
     * @since   Kunena 6.0
     */
    public $subscribed;

    /**
     * Returns \Kunena\Forum\Libraries\Forum\Topic\TopicUser object.
     *
     * @param   KunenaTopic|int|null  $topic   topic
     * @param   mixed                 $user    user
     * @param   bool                  $reload  reload
     *
     * @return  KunenaTopicUser
     *
     * @since   Kunena 6.0
     * @throws  Exception
     */
    public static function get($topic = null, $user = null, $reload = false): KunenaTopicUser
    {
        if ($topic instanceof KunenaTopic) {
            $topic = $topic->id;
        }

        $topic = \intval($topic);
        $user  = KunenaUserHelper::get($user);

        if ($topic < 1) {
            return new KunenaTopicUser(null, $user);
        }

        if ($reload || empty(self::$_instances [$user->userid][$topic])) {
            $topics                                   = self::getTopics($topic, $user);
            self::$_instances [$user->userid][$topic] = self::$_topics [$topic][$user->userid] = array_pop($topics);
        }

        return self::$_instances [$user->userid][$topic];
    }

    /**
     * @param   bool|array  $ids   ids
     * @param   mixed       $user  user
     *
     * @return  KunenaTopicUser[]
     *
     * @since   Kunena 6.0
     * @throws  Exception
     */
    public static function getTopics($ids = false, $user = null)
    {
        $user = KunenaUserHelper::get($user);

        if ($ids === false) {
            return isset(self::$_instances[$user->userid]) ? self::$_instances[$user->userid] : [];
        }

        if (!\is_array($ids)) {
            $ids = [$ids];
        }

        // Convert topic objects into ids
        foreach ($ids as $i => $id) {
            if ($id instanceof KunenaTopic) {
                $ids[$i] = $id->id;
            }
        }

        $ids = array_unique($ids);
        self::loadTopics($ids, $user);

        $list = [];

        foreach ($ids as $id) {
            if (!empty(self::$_instances [$user->userid][$id])) {
                $list [$id] = self::$_instances [$user->userid][$id];
            }
        }

        return $list;
    }

    /**
     * @param   array       $ids   ids
     * @param   KunenaUser  $user  user
     *
     * @return  void
     *
     * @since   Kunena 6.0
     * @throws  Exception
     */
    protected static function loadTopics(array $ids, KunenaUser $user): void
    {
        foreach ($ids as $i => $id) {
            $id = \intval($id);

            if (!$id || isset(self::$_instances [$user->userid][$id])) {
                unset($ids[$i]);
            }
        }

        if (empty($ids)) {
            return;
        }

        $idlist = implode(',', $ids);
        $db     = Factory::getContainer()->get('DatabaseDriver');
        $query  = $db->createQuery();
        $query->select('*')
            ->from($db->quoteName('#__kunena_user_topics'))
            ->where($db->quoteName('user_id') . ' = ' . $db->quote($user->userid))
            ->andWhere($db->quoteName('topic_id') . ' IN (' . $idlist . ')');
        $db->setQuery($query);

        try {
            $results = (array) $db->loadAssocList('topic_id');
        } catch (ExecutionFailureException $e) {
            KunenaError::displayDatabaseError($e);
        }

        foreach ($ids as $id) {
            if (isset($results[$id])) {
                $instance = new KunenaTopicUser();

                if (!empty($results)) {
                    $instance->bind($results[$id]);
                }

                $instance->exists(true);
                self::$_instances [$user->userid][$id] = self::$_topics [$id][$user->userid] = $instance;
            } else {
                self::$_instances [$user->userid][$id] = self::$_topics [$id][$user->userid] = new KunenaTopicUser($id, $user->userid);
            }
        }

        unset($results);
    }

    /**
     * Get all user ids who have participated to the given topics.
     *
     * @param   array|KunenaTopic[]  $topics  topics
     * @param   string               $value   Row to pick up as value.
     *
     * @return  array List of [topic][userid] = value.
     *
     * @since   Kunena 6.0
     * @throws  Exception
     */
    public static function getUserIds(array $topics, $value = 'user_id'): array
    {
        // Convert topic objects into ids
        $ids = [];

        foreach ($topics as $id) {
            if ($id instanceof KunenaTopic) {
                $ids[(int) $id->id] = (int) $id->id;
            } else {
                $ids[(int) $id] = (int) $id;
            }
        }

        $idlist = implode(',', $ids);

        $db    = Factory::getContainer()->get('DatabaseDriver');
        $query = $db->createQuery();
        $query->select('topic_id, user_id')
            ->from($db->quoteName('#__kunena_user_topics'))
            ->where($db->quoteName('topic_id') . ' IN (' . $idlist . ')')
            ->where($db->quoteName('posts') . ' > 0');

        $query->select($db->quoteName($value));

        $db->setQuery($query);

        try {
            $results = $db->loadObjectList();
        } catch (ExecutionFailureException $e) {
            KunenaError::displayDatabaseError($e);
        }

        $list = [];

        if (!empty($results)) {
            foreach ($results as $key => $result) {
                $list[$key] = $result->user_id;
            }
        }

        return $list;
    }

    /**
     * @param   KunenaTopic  $old  old
     * @param   KunenaTopic  $new  new
     *
     * @return  boolean
     *
     * @since   Kunena 6.0
     * @throws Exception
     */
    public static function move(KunenaTopic $old, KunenaTopic $new): bool
    {
        // Update database
        $db    = Factory::getContainer()->get('DatabaseDriver');
        $query = $db->createQuery();
        $query->update($db->quoteName('#__kunena_user_topics'))
            ->set($db->quoteName('topic_id') . ' = ' . $db->quote($new->id))
            ->set($db->quoteName('category_id') . ' = ' . $db->quote($new->category_id))
            ->where($db->quoteName('topic_id') . ' = ' . $db->quote($old->id));
        $db->setQuery($query);

        try {
            $db->execute();
        } catch (ExecutionFailureException $e) {
            KunenaError::displayDatabaseError($e);

            return false;
        }

        // Update internal state
        if (isset(self::$_topics [$old->id])) {
            if ($new->id != $old->id) {
                self::$_topics [$new->id] = self::$_topics [$old->id];
                unset(self::$_topics [$old->id]);
            }

            foreach (self::$_topics [$new->id] as $instance) {
                $instance->topic_id    = $new->id;
                $instance->category_id = $new->category_id;
            }
        }

        return true;
    }

    /**
     * @param   KunenaTopic  $old  old
     * @param   KunenaTopic  $new  new
     *
     * @return  boolean
     *
     * @since   Kunena 6.0
     * @throws Exception
     */
    public static function merge(KunenaTopic $old, KunenaTopic $new): bool
    {
        $db = Factory::getContainer()->get('DatabaseDriver');

        // Move all user topics which do not exist in new topic
        $queries[] = "UPDATE #__kunena_user_topics AS ut
			INNER JOIN #__kunena_user_topics AS o ON o.user_id = ut.user_id
			SET ut.topic_id={$db->quote($new->id)}, ut.category_id={$db->quote($new->category_id)}
			WHERE o.topic_id={$db->quote($old->id)} AND ut.topic_id IS NULL";

        // Merge user topics information that exists in both topics
        $queries[] = "UPDATE #__kunena_user_topics AS ut
			INNER JOIN #__kunena_user_topics AS o ON o.user_id = ut.user_id
			SET ut.posts = o.posts + ut.posts,
				ut.last_post_id = GREATEST( o.last_post_id, ut.last_post_id ),
				ut.owner = GREATEST( o.owner, ut.owner ),
				ut.favorite = GREATEST( o.favorite, ut.favorite ),
				ut.subscribed = GREATEST( o.subscribed, ut.subscribed )
				WHERE ut.topic_id = {$db->quote($new->id)}
				AND o.topic_id = {$db->quote($old->id)}";

        // Delete all user topics from the shadow topic
        $queries[] = "DELETE FROM #__kunena_user_topics WHERE topic_id={$db->quote($old->id)}";

        foreach ($queries as $query) {
            $db->setQuery($query);

            try {
                $db->execute();
            } catch (ExecutionFailureException $e) {
                KunenaError::displayDatabaseError($e);

                return false;
            }
        }

        // Update internal state
        self::reloadTopic($old->id);
        self::reloadTopic($new->id);

        return true;
    }

    /**
     * @param   int  $id  id
     *
     * @return  void
     *
     * @since   Kunena 6.0
     * @throws Exception
     */
    protected static function reloadTopic(int $id): void
    {
        if (empty(self::$_topics [$id])) {
            return;
        }

        $idlist = implode(',', array_keys(self::$_topics [$id]));
        $db     = Factory::getContainer()->get('DatabaseDriver');
        $query  = $db->createQuery();
        $query->select('*')
            ->from($db->quoteName('#__kunena_user_topics'))
            ->where($db->quoteName('user_id') . ' IN (' . $idlist . ')')
            ->where($db->quoteName('topic_id') . ' = ' . $db->quote($id));
        $db->setQuery($query);

        try {
            $results = (array) $db->loadAssocList('user_id');
        } catch (ExecutionFailureException $e) {
            KunenaError::displayDatabaseError($e);
        }

        // TODO: Is there a bug?
        foreach (self::$_topics[$id] as $instance) {
            if (isset($results[$instance->user_id])) {
                $instance->bind($results[$instance->user_id]);
                $instance->exists(true);
            } else {
                $instance->reset();
            }
        }

        unset($results);
    }

    /**
     * Free up memory by cleaning up all cached items.
     *
     * @return  void
     *
     * @since   Kunena 6.0
     */
    public static function cleanup(): void
    {
        self::$_instances = [];
        self::$_topics    = [];
    }

    /**
     * @param   bool|array|int  $topicids  topicids
     * @param   int             $start     start
     * @param   int             $end       end
     *
     * @return  boolean|integer
     *
     * @since   Kunena 6.0
     * @throws  Exception
     */
    public static function recount($topicids = false, $start = 0, $end = 0)
    {
        $db = Factory::getContainer()->get('DatabaseDriver');

        if (\is_array($topicids)) {
            $where  = 'AND m.thread IN (' . implode(',', $topicids) . ')';
            $where2 = 'AND ut.topic_id IN (' . implode(',', $topicids) . ')';
        } elseif ((int) $topicids) {
            $where  = 'AND m.thread=' . (int) $topicids;
            $where2 = 'AND ut.topic_id=' . (int) $topicids;
        } else {
            $where  = '';
            $where2 = '';
        }

        if ($end) {
            $where  .= " AND (m.thread BETWEEN {$start} AND {$end})";
            $where2 .= " AND (ut.topic_id BETWEEN {$start} AND {$end})";
        }

        // Create missing user topics and update post count and last post if there are posts by that user
        $subQuery = $db->createQuery();
        $query    = $db->createQuery();

        // Create the base subQuery select statement.
        $subQuery->select('m.userid AS `user_id`, m.thread AS `topic_id`, m.catid AS `category_id`, SUM(m.hold=0) AS `posts`, MAX(IF(m.hold=0,m.id,0)) AS `last_post_id`, MAX(IF(m.parent=0,1,0)) AS `owner`')
            ->from($db->quoteName('#__kunena_messages', 'm'))
            ->where($db->quoteName('m.userid') . ' > 0 AND ' . $db->quoteName('m.moved') . ' = 0 ' . $where)
            ->group('m.userid, m.thread');

        // Create the base insert statement.
        $query->insert(
        	$db->quoteName('#__kunena_user_topics') . ' (`user_id`, `topic_id`, `category_id`, `posts`, `last_post_id`, `owner`) ' . $subQuery . '
			ON DUPLICATE KEY UPDATE `category_id` = VALUES(`category_id`), `posts` = VALUES(`posts`), `last_post_id` = VALUES(`last_post_id`)'
        );
        $db->setQuery($query);

        try {
            $db->execute();
        } catch (ExecutionFailureException $e) {
            KunenaError::displayDatabaseError($e);

            return false;
        }

        $rows = $db->getAffectedRows();

        // Find user topics where last post doesn't exist and reset values in it
        $query = $db->createQuery();
        $query->update($db->quoteName('#__kunena_user_topics', 'ut'))
            ->leftJoin($db->quoteName('#__kunena_messages', 'm') . ' ON ' . $db->quoteName('ut.last_post_id') . ' = ' . $db->quoteName('m.id') . ' AND ' . $db->quoteName('m.hold') . ' = 0')
            ->set($db->quoteName('posts') . ' = 0')
            ->set($db->quoteName('last_post_id') . ' = 0')
            ->where($db->quoteName('m.id') . ' IS NULL ' . $where2);
        $db->setQuery($query);

        try {
            $db->execute();
        } catch (ExecutionFailureException $e) {
            KunenaError::displayDatabaseError($e);

            return false;
        }

        $rows += $db->getAffectedRows();

        // Delete entries that have default values
        $query = "DELETE ut FROM #__kunena_user_topics AS ut WHERE ut.posts=0 AND ut.owner=0 AND ut.favorite=0 AND ut.subscribed=0 AND ut.params='' {$where2}";

        $db->setQuery($query);

        try {
            $db->execute();
        } catch (ExecutionFailureException $e) {
            KunenaError::displayDatabaseError($e);

            return false;
        }

        $rows += $db->getAffectedRows();

        return $rows;
    }
}