<?php
/**
 * ownCloud - bookmarks plugin
 *
 * @author Arthur Schiwon
 * @copyright 2011 Arthur Schiwon blizzz@arthur-schiwon.de
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU AFFERO GENERAL PUBLIC LICENSE for more details.
 *
 * You should have received a copy of the GNU Affero General Public
 * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

/**
 * This class manages bookmarks
 */
class OC_Bookmarks_Bookmarks{


	/**
	* @brief Find People with whome we shared bookmarks and how much
	*/
	public static function findSharing($offset = 0, $limit = 10){
		$query = OCP\DB::prepare('SELECT \'@public\' as name, count(*) as nbr from  *PREFIX*bookmarks where public=1 group by public LIMIT '.$offset.',  '.$limit);
		$tags = $query->execute()->fetchAll();
		return $tags;
	}
	/**
	* @brief Finds all tags for bookmarks
	*/
	public static function findTags($filterTags = array(), $offset = 0, $limit = 10){
		//$query = OCP\DB::prepare('SELECT tag, count(*) as nbr from  *PREFIX*bookmarks_tags group by tag LIMIT '.$offset.',  '.$limit);

		$params = array_merge($filterTags,$filterTags);
		$not_in = '';

		if(!empty($filterTags) ) {
			$not_in = ' where tag not in ('. implode(',',array_fill(0, count($filterTags) ,'?') ) .')'.
			str_repeat(" AND	exists (select 1 from  *PREFIX*bookmarks_tags t2 where t2.bookmark_id = t.bookmark_id and tag = ?) ", count($filterTags));
		}
		$sql = 'SELECT tag, count(*) as nbr from *PREFIX*bookmarks_tags t '.$not_in.
			'group by tag Order by nbr DESC LIMIT '.$offset.',  '.$limit;
		$query = OCP\DB::prepare($sql);
		$tags = $query->execute($params)->fetchAll();
		return $tags;
	}
	/**
	 * @brief Finds all bookmarks, matching the filter
	 * @param offset result offset
	 * @param sqlSortColumn sort result with this column
	 * @param filter can be: empty -> no filter, a string -> filter this, a string array -> filter for all strings
	 * @param filterTagOnly if true, filter affects only tags, else filter affects url, title and tags
	 * @return void
	 */
	public static function findBookmarks($offset, $sqlSortColumn, $filter, $filterTagOnly){
		//$CONFIG_DBTYPE = OCP\Config::getSystemValue( 'dbtype', 'sqlite' );
		$limit = 10;
		$params=array(OCP\USER::getUser());
		//@TODO replace GROUP_CONCAT for postgresql
		$sql = "SELECT *, (select GROUP_CONCAT(tag) from *PREFIX*bookmarks_tags where bookmark_id = b.id) as tags
				FROM *PREFIX*bookmarks b
				WHERE user_id = ? ";

		if($filterTagOnly) {
			if(is_string($filter)) $filter = array($filter);

			$sql .= str_repeat(" AND	exists (select id from  *PREFIX*bookmarks_tags t2 where t2.bookmark_id = b.id and tag = ?) ", count($filter));
			$params = array_merge($params, $filter);
		}
		$sql .= " ORDER BY ".$sqlSortColumn." DESC
				LIMIT $limit
				OFFSET  $offset";

		$query = OCP\DB::prepare($sql);
		$results = $query->execute($params)->fetchAll();
		$bookmarks = array();
		foreach($results as $result){
			$result['tags'] = explode(',', $result['tags']);
			$bookmarks[] = $result;
		}
		return $bookmarks;
	}

	public static function deleteUrl($id)
	{
		$user = OCP\USER::getUser();

		$query = OCP\DB::prepare("
				SELECT `id` FROM `*PREFIX*bookmarks`
				WHERE `id` = ?
				AND `user_id` = ?
				");

		$result = $query->execute(array($id, $user));
		$id = $result->fetchOne();
		if ($id === false) {
			return false;
		}

		$query = OCP\DB::prepare("
			DELETE FROM `*PREFIX*bookmarks`
			WHERE `id` = $id
			");

		$result = $query->execute();

		$query = OCP\DB::prepare("
			DELETE FROM `*PREFIX*bookmarks_tags`
			WHERE `bookmark_id` = $id
			");

		$result = $query->execute();
		return true;
	}

	public static function renameTag($old, $new)
	{
		$user_id = OCP\USER::getUser();

		// Update the record
		$query = OCP\DB::prepare("
		UPDATE *PREFIX*bookmarks_tags SET
			tag = ?
		WHERE tag = ?
		AND exists( select id from *PREFIX*bookmarks where user_id = ? and bookmark_id = id)
		");

		$params=array(
			$new,
			$old,
			$user_id,
		);

		$result = $query->execute($params);
		return true;
	}

	public static function deleteTag($old)
	{
		$user_id = OCP\USER::getUser();

		// Update the record
		$query = OCP\DB::prepare("
		DELETE FROM *PREFIX*bookmarks_tags
		WHERE tag = ?
		AND exists( select id from *PREFIX*bookmarks where user_id = ? and bookmark_id = id)
		");

		$params=array(
			$old,
			$user_id,
		);

		$result = $query->execute($params);
		return true;
	}

	/**
	* get a string corresponding to the current time depending
	* of the OC database system
	* @return string
	*/
	protected static function getNowValue() {
		$CONFIG_DBTYPE = OCP\Config::getSystemValue( "dbtype", "sqlite" );
		if( $CONFIG_DBTYPE == 'sqlite' or $CONFIG_DBTYPE == 'sqlite3' ){
			$_ut = "strftime('%s','now')";
		} elseif($CONFIG_DBTYPE == 'pgsql') {
			$_ut = 'date_part(\'epoch\',now())::integer';
		} else {
			$_ut = "UNIX_TIMESTAMP()";
		}
		return $_ut;
	}

	/**
	 * Edit a bookmark
	 * @param int $id The id of the bookmark to edit
	 * @param string $url
	 * @param string $title Name of the bookmark
	 * @param array $tags Simple array of tags to qualify the bookmark (different tags are taken from values)
	 * @param string $description A longer description about the bookmark
	 * @param boolean $is_public True if the bookmark is publishable to not registered users
	 * @return null
	 */
	public static function editBookmark($id, $url, $title, $tags = array(), $description='', $is_public=false) {

		$is_public = $is_public ? 1 : 0;
		$user_id = OCP\USER::getUser();

		// Update the record
		$query = OCP\DB::prepare("
		UPDATE *PREFIX*bookmarks SET
			url = ?, title = ?, public = ?, description = ?,
			lastmodified = ".self::getNowValue() ."
		WHERE id = ?
		AND user_id = ?
		");

		$params=array(
			htmlspecialchars_decode($url),
			htmlspecialchars_decode($title),
			$is_public,
			htmlspecialchars_decode($description),
			$id,
			$user_id,
		);

		$result = $query->execute($params);

		// Abort the operation if bookmark couldn't be set
		// (probably because the user is not allowed to edit this bookmark)
		if ($result->numRows() == 0) exit();


		// Remove old tags
		$sql = "DELETE from *PREFIX*bookmarks_tags  WHERE bookmark_id = ?";
		$query = OCP\DB::prepare($sql);
		$query->execute(array($id));

		// Add New Tags
		self::addTags($id, $tags);
	}

	/**
 * Add a bookmark
	 * @param string $url
	 * @param string $title Name of the bookmark
	 * @param array $tags Simple array of tags to qualify the bookmark (different tags are taken from values)
	 * @param string $description A longer description about the bookmark
	 * @param boolean $is_public True if the bookmark is publishable to not registered users
	 * @return int The id of the bookmark created
	 */
	public static function addBookmark($url, $title, $tags=array(), $description='', $is_public=false) {

		$is_public = $is_public ? 1 : 0;
		//FIXME: Detect and do smth when user adds a known URL
		$_ut = self::getNowValue();

		$query = OCP\DB::prepare("
			INSERT INTO *PREFIX*bookmarks
			(url, title, user_id, public, added, lastmodified, description)
			VALUES (?, ?, ?, ?, $_ut, $_ut, ?)
			");

		$params=array(
			htmlspecialchars_decode($url),
			htmlspecialchars_decode($title),
			OCP\USER::getUser(),
			$is_public,
			$description,
		);
		$query->execute($params);

		$b_id = OCP\DB::insertid('*PREFIX*bookmarks');

		if($b_id !== false) {
			self::addTags($b_id, $tags);
			return $b_id;
		}
	}

	/**
	 * Add a set of tags for a bookmark
	 * @param int $bookmark_id The bookmark reference
	 * @param array $tags Set of tags to add to the bookmark
	 * @return null
	 **/
	private static function addTags($bookmark_id, $tags) {
		$query = OCP\DB::prepare("
			INSERT INTO *PREFIX*bookmarks_tags
			(bookmark_id, tag)
			VALUES (?, ?)");

		foreach ($tags as $tag) {
			if(empty($tag)) {
				//avoid saving blankspaces
				continue;
			}
			$params = array($bookmark_id, trim($tag));
			$query->execute($params);
		}
	}
}