<?php
/**
 * Kunena Component
 * @package Kunena.Framework
 * @subpackage Forum.Message
 *
 * @copyright (C) 2008 - 2018 Kunena Team. All rights reserved.
 * @license https://www.gnu.org/copyleft/gpl.html GNU/GPL
 * @link https://www.kunena.org
 **/
defined('_JEXEC') or die();

/**
 * Kunena Forum Message Helper Class
 */
abstract class KunenaForumMessageHelper
{
	/**
	 * @var KunenaForumMessage[]
	 */
	protected static $_instances = array();
	protected static $_location = array();

	/**
	 * Returns KunenaForumMessage object.
	 *
	 * @param   null $identifier	The message to load - Can be only an integer.
	 * @param   bool $reload
	 *
	 * @return KunenaForumMessage	The message object.
	 */
	static public function get($identifier = null, $reload = false)
	{
		if ($identifier instanceof KunenaForumMessage)
		{
			return $identifier;
		}

		$id = (int) $identifier;

		if ($id < 1)
		{
			return new KunenaForumMessage;
		}

		if (empty(self::$_instances[$id]))
		{
			$instance = new KunenaForumMessage;
			// Only load messages which haven't been preloaded before (including missing ones).
			$instance->load(!array_key_exists($id, self::$_instances) ? $id : null);
			$instance->id = $id;
			self::$_instances[$id] = $instance;
		}
		elseif ($reload)
		{
			self::$_instances[$id]->load();
		}

		return self::$_instances[$id];
	}

	/**
	 * @param   bool|array|int   $ids
	 * @param   string $authorise
	 *
	 * @return KunenaForumMessage[]
	 */
	static public function getMessages($ids = false, $authorise='read')
	{
		if ($ids === false)
		{
			return self::$_instances;
		}
		elseif (is_array($ids))
		{
			$ids = array_unique($ids);
		}
		else
		{
			$ids = array($ids);
		}

		self::loadMessages($ids);

		$list = array ();
		foreach ($ids as $id)
		{
			// TODO: authorisation needs topics to be loaded, make sure that they are! (performance increase)
			if (!empty(self::$_instances [$id]) && self::$_instances [$id]->authorise($authorise, null, true))
			{
				$list [$id] = self::$_instances [$id];
			}
		}

		return $list;
	}

	/**
	 * @param   mixed  $topic
	 * @param   int    $start
	 * @param   int    $limit
	 * @param   string $ordering
	 * @param   int    $hold
	 * @param   bool   $orderbyid
	 *
	 * @return KunenaForumMessage[]
	 */
	static public function getMessagesByTopic($topic, $start=0, $limit=0, $ordering='ASC', $hold=0, $orderbyid = false)
	{
		$topic = KunenaForumTopicHelper::get($topic);
		if (!$topic->exists())
		{
			return array();
		}

		$total = $topic->getTotal();

		if ($start < 0)
		{
			$start = 0;
		}

		if ($limit < 1)
		{
			$limit = KunenaFactory::getConfig()->messages_per_page;
		}

		// If out of range, use last page
		if ($total < $start)
		{
			$start = intval($total / $limit) * $limit;
		}

		$ordering = strtoupper($ordering);

		if ($ordering != 'DESC')
		{
			$ordering = 'ASC';
		}

		return self::loadMessagesByTopic($topic->id, $start, $limit, $ordering, $hold, $orderbyid);
	}

	/**
	 * @param   bool|array|int  $categories
	 * @param   int   $limitstart
	 * @param   int   $limit
	 * @param   array $params
	 *
	 * @return array
	 */
	static public function getLatestMessages($categories = false, $limitstart = 0, $limit = 0, $params = array())
	{
		$reverse = isset($params['reverse']) ? (int) $params['reverse'] : 0;
		$orderby = isset($params['orderby']) ? (string) $params['orderby'] : 'm.time DESC';
		$starttime = isset($params['starttime']) ? (int) $params['starttime'] : 0;
		$mode = isset($params['mode']) ? $params['mode'] : 'recent';
		$user = isset($params['user']) ? $params['user'] : false;
		$where = isset($params['where']) ? (string) $params['where'] : '';
		$childforums = isset($params['childforums']) ? (bool) $params['childforums'] : false;

		$db = JFactory::getDBO();

		// FIXME: use right config setting
		if ($limit < 1 && empty($params['nolimit']))
		{
			$limit = KunenaFactory::getConfig()->threads_per_page;
		}

		$query = $db->getQuery(true);
		$query->select('m.*, t.message')
			->from('#__kunena_messages AS m')
			->innerJoin('#__kunena_messages_text AS t ON m.id = t.mesid')
			->where('m.moved=0') // TODO: remove column
			->order($orderby);

		$authorise = 'read';
		$hold = 'm.hold=0';
		$userfield = 'm.userid';

		switch ($mode)
		{
			case 'unapproved':
				$authorise = 'approve';
				$hold = "m.hold=1";
				break;
			case 'deleted':
				$authorise = 'undelete';
				$hold = "m.hold>=2";
				break;
			case 'mythanks':
				$userfield = 'th.userid';
				$query->innerJoin('#__kunena_thankyou AS th ON m.id = th.postid');
				break;
			case 'thankyou':
				$userfield = 'th.targetuserid';
				$query->innerJoin('#__kunena_thankyou AS th ON m.id = th.postid');
				break;
			case 'recent':
			default:
		}

		if (is_array($categories) && in_array(0, $categories))
		{
			$categories = false;
		}

		$categories = KunenaForumCategoryHelper::getCategories($categories, $reverse, 'topic.' . $authorise);

		if ($childforums)
		{
			$categories += KunenaForumCategoryHelper::getChildren($categories, -1, array('action' => 'topic.' . $authorise));
		}

		$catlist = array();

		foreach ($categories as $category)
		{
			$catlist += $category->getChannels();
		}

		if (empty($catlist))
		{
			return array(0, array());
		}

		$allowed = implode(',', array_keys($catlist));
		$query->where("m.catid IN ({$allowed})");

		$query->where($hold);

		if ($user)
		{
			$query->where("{$userfield}={$db->Quote($user)}");
		}

		// Negative time means no time
		if ($starttime == 0)
		{
			$starttime = KunenaFactory::getSession()->lasttime;
		}
		elseif ($starttime > 0)
		{
			$starttime = JFactory::getDate()->toUnix() - ($starttime * 3600);
		}

		if ($starttime > 0)
		{
			$query->where("m.time>{$db->Quote($starttime)}");
		}

		if ($where)
		{
			$query->where($where);
		}

		$cquery = clone $query;
		$cquery->clear('select')->clear('order')->select('COUNT(*)');
		$db->setQuery($cquery);

		try
		{
			$total = (int) $db->loadResult();
		}
		catch (JDatabaseExceptionExecuting $e)
		{
			KunenaError::displayDatabaseError($e);

			return array(0, array());
		}

		if (!$total)
		{
			return array(0, array());
		}

		// If out of range, use last page
		if ($limit && $total < $limitstart)
		{
			$limitstart = intval($total / $limit) * $limit;
		}

		$db->setQuery($query, $limitstart, $limit);

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

			return array(0, array());
		}

		$messages = array();
		foreach ($results as $result)
		{
			$instance = new KunenaForumMessage($result);
			$instance->exists(true);
			self::$_instances [$instance->id] = $instance;
			$messages[$instance->id] = $instance;
		}

		unset($results);

		return array($total, $messages);
	}

	/**
	 * @param   int $mesid
	 * @param   null|string $direction
	 * @param   null|array $hold
	 *
	 * @return integer
	 */
	public static function getLocation($mesid, $direction = null, $hold = null)
	{
		if (is_null($direction))
		{
			$direction = KunenaUserHelper::getMyself()->getMessageOrdering();
		}

		if (!$hold)
		{
			$me = KunenaUserHelper::getMyself();
			$mes_instance = self::get($mesid);
			$hold = KunenaAccess::getInstance()->getAllowedHold($me->userid, $mes_instance->catid, false);
		}

		if (!isset(self::$_location [$mesid]))
		{
			self::loadLocation(array($mesid));
		}

		$location = self::$_location [$mesid];
		$count = 0;

		foreach ($location->hold as $meshold => $values)
		{
			if (isset($hold[$meshold]))
			{
				$count += $values[$direction == 'asc' ? 'before' : 'after'];

				if ($direction == 'both')
				{
					$count += $values['before'];
				}
			}
		}

		return $count;
	}

	/**
	 * @param   array|string $mesids
	 */
	public static function loadLocation($mesids)
	{
		// NOTE: if you already know the location using this code just takes resources
		if (!is_array($mesids))
		{
			$mesids = explode(',', $mesids);
		}

		$ids = array();

		foreach ($mesids as $id)
		{
			if ($id instanceof KunenaForumMessage)
			{
				$id = $id->id;
			}
			else
			{
				$id = (int) $id;
			}

			if (!isset(self::$_location [$id])) {
				$ids[$id] = $id;
				self::$_location [$id] = new stdClass();
				self::$_location [$id]->hold = array('before' => 0, 'after' => 0);
			}
		}

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

		$idlist = implode(',', $ids);
		$db = JFactory::getDBO();
		$db->setQuery(
   "SELECT m.id, mm.hold, m.catid AS category_id, m.thread AS topic_id,
				SUM(mm.time<m.time) AS before_count,
				SUM(mm.time>m.time) AS after_count
			FROM #__kunena_messages AS m
			INNER JOIN #__kunena_messages AS mm ON m.thread=mm.thread
			WHERE m.id IN ({$idlist})
			GROUP BY m.id, mm.hold" );

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

		foreach ($results as $result)
		{
			$instance = self::$_location [$result->id];

			if (!isset($instance->id))
			{
				$instance->id = $result->id;
				$instance->category_id = $result->category_id;
				$instance->topic_id = $result->topic_id;
				self::$_location [$instance->id] = $instance;
			}

			$instance->hold[$result->hold] = array('before' => $result->before_count, 'after' => $result->after_count);
		}
	}

	/**
	 * Free up memory by cleaning up all cached items.
	 */
	public static function cleanup()
	{
		self::$_instances = array();
		self::$_location = array();
	}

	/**
	 * @param   bool|array|int $topicids
	 *
	 * @return boolean|integer
	 */
	public static function recount($topicids = false)
	{
		$db = JFactory::getDBO();

		if (is_array($topicids))
		{
			$where = 'WHERE m.thread IN (' . implode(',', $topicids) . ')';
		}
		elseif ((int) $topicids)
		{
			$where = 'WHERE m.thread=' . (int) $topicids;
		}
		else
		{
			$where = '';
		}

		// Update catid in all messages
		$query = "UPDATE #__kunena_messages AS m
			INNER JOIN #__kunena_topics AS tt ON tt.id=m.thread
			SET m.catid=tt.category_id {$where}";
		$db->setQuery($query);

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

			return false;
		}

		return $db->getAffectedRows();
	}

	// Internal functions

	/**
	 * @param   array $ids
	 *
	 * @return bool
	 */
	static protected function loadMessages(array $ids)
	{
		foreach ($ids as $i => $id)
		{
			$id = intval($id);

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

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

		$idlist = implode(',', $ids);
		$db = JFactory::getDBO();
		$query = "SELECT m.*, t.message FROM #__kunena_messages AS m INNER JOIN #__kunena_messages_text AS t ON m.id=t.mesid WHERE m.id IN ({$idlist})";
		$db->setQuery($query);

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

			return false;
		}

		foreach ($ids as $id)
		{
			if (isset($results[$id]))
			{
				$instance = new KunenaForumMessage($results[$id]);
				$instance->exists(true);
				self::$_instances [$id] = $instance;
			}
			else
			{
				self::$_instances [$id] = null;
			}
		}

		unset($results);
	}

	static public function getMessagesByTopics(array $ids)
	{
		if (empty($ids))
		{
			return;
		}

		$db = JFactory::getDBO();

		$idlist = implode(',', $ids);
		$query = "SELECT m.*, t.message
		FROM #__kunena_messages AS m
		INNER JOIN #__kunena_messages_text AS t ON m.id=t.mesid
		WHERE m.thread IN ({$idlist}) AND m.hold=0";
		$db->setQuery($query);

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

		return $results;
	}

	/**
	 * @param   int    $topic_id
	 * @param   int    $start
	 * @param   int    $limit
	 * @param   string $ordering
	 * @param   int    $hold
	 * @param   bool   $orderbyid
	 *
	 * @return array
	 */
	static protected function loadMessagesByTopic($topic_id, $start = 0, $limit = 0, $ordering = 'ASC', $hold=0, $orderbyid = false)
	{
		$db = JFactory::getDBO();
		$query = "SELECT m.*, t.message
			FROM #__kunena_messages AS m
			INNER JOIN #__kunena_messages_text AS t ON m.id=t.mesid
			WHERE m.thread={$db->quote($topic_id)} AND m.hold IN ({$hold}) ORDER BY m.time {$ordering}";
		$db->setQuery($query, $start, $limit);

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

		$location = ($orderbyid || $ordering == 'ASC') ? $start : KunenaForumTopicHelper::get($topic_id)->getTotal($hold) - $start - 1;
		$order = ($ordering == 'ASC') ? 1 : -1;
		$list = array();

		foreach ($results as $id => $result)
		{
			$instance = new KunenaForumMessage($result);
			$instance->exists(true);
			self::$_instances [$id] = $instance;
			$list[$orderbyid ? $id : $location] = $instance;
			$location += $order;
		}

		unset($results);

		return $list;
	}
}