<?php
/////////////////////////////////////////////////////////////////
/// getID3() by James Heinrich <info@getid3.org>               //
//  available at https://github.com/JamesHeinrich/getID3       //
//            or https://www.getid3.org                        //
//            or http://getid3.sourceforge.net                 //
//                                                             //
// extension.cache.mysqli.php - part of getID3()               //
// Please see readme.txt for more information                  //
//                                                             //
/////////////////////////////////////////////////////////////////
//                                                             //
// extension.cache.sqlite3.php - part of getID3()              //
// Please see readme.txt for more information                  //
//                                                             //
/////////////////////////////////////////////////////////////////
///                                                            //
// MySQL extension written by Allan Hansen <ahØartemis*dk>     //
// Table name mod by Carlo Capocasa <calroØcarlocapocasa*com>  //
// MySQL extension was reworked for SQLite3 by                 //
//   Karl G. Holz <newaeonØmac*com>                            //
//                                                            ///
/////////////////////////////////////////////////////////////////

/**
* This is a caching extension for getID3(). It works the exact same
* way as the getID3 class, but return cached information much faster
*
*    Normal getID3 usage (example):
*
*       require_once 'getid3/getid3.php';
*       $getID3 = new getID3;
*       $getID3->encoding = 'UTF-8';
*       $info1 = $getID3->analyze('file1.flac');
*       $info2 = $getID3->analyze('file2.wv');
*
*    getID3_cached usage:
*
*       require_once 'getid3/getid3.php';
*       require_once 'getid3/extension.cache.sqlite3.php';
*       // all parameters are optional, defaults are:
*       $getID3 = new getID3_cached_sqlite3($table='getid3_cache', $hide=FALSE);
*       $getID3->encoding = 'UTF-8';
*       $info1 = $getID3->analyze('file1.flac');
*       $info2 = $getID3->analyze('file2.wv');
*
*
* Supported Cache Types    (this extension)
*
*   SQL Databases:
*
*   cache_type          cache_options
*   -------------------------------------------------------------------
*   mysql               host, database, username, password
*
*   sqlite3             table='getid3_cache', hide=false        (PHP5)
*
*
* ***  database file will be stored in the same directory as this script,
* ***  webserver must have write access to that directory!
* ***  set $hide to TRUE to prefix db file with .ht to pervent access from web client
* ***  this is a default setting in the Apache configuration:
*
* The following lines prevent .htaccess and .htpasswd files from being viewed by Web clients.
*
* <Files ~ "^\.ht">
*     Order allow,deny
*     Deny from all
*     Satisfy all
* </Files>
*
********************************************************************************
*
*   -------------------------------------------------------------------
*   DBM-Style Databases:    (use extension.cache.dbm)
*
*   cache_type          cache_options
*   -------------------------------------------------------------------
*   gdbm                dbm_filename, lock_filename
*   ndbm                dbm_filename, lock_filename
*   db2                 dbm_filename, lock_filename
*   db3                 dbm_filename, lock_filename
*   db4                 dbm_filename, lock_filename  (PHP5 required)
*
*   PHP must have write access to both dbm_filename and lock_filename.
*
* Recommended Cache Types
*
*   Infrequent updates, many reads      any DBM
*   Frequent updates                    mysql
********************************************************************************
*
* IMHO this is still a bit slow, I'm using this with MP4/MOV/ M4v files
* there is a plan to add directory scanning and analyzing to make things work much faster
*
*
*/
class getID3_cached_sqlite3 extends getID3
{
	/**
	 * hold the sqlite db
	 *
	 * @var SQLite3 Resource
	 */
	private $db;

	/**
	 * table to use for caching
	 *
	 * @var string $table
	 */
	private $table;

	/**
	 * @param string  $table holds name of sqlite table
	 * @param boolean $hide
	 *
	 * @throws getid3_exception
	 * @throws Exception
	 */
	public function __construct($table='getid3_cache', $hide=false) {
		// Check for SQLite3 support
		if (!function_exists('sqlite_open')) {
			throw new Exception('PHP not compiled with SQLite3 support.');
		}

		$this->table = $table; // Set table
		$file = dirname(__FILE__).'/'.basename(__FILE__, 'php').'sqlite';
		if ($hide) {
			$file = dirname(__FILE__).'/.ht.'.basename(__FILE__, 'php').'sqlite';
		}
		$this->db = new SQLite3($file);
		$db = $this->db;
		$this->create_table();   // Create cache table if not exists
		$version = '';
		$sql = $this->getQuery('version_check');
		$stmt = $db->prepare($sql);
		$stmt->bindValue(':filename', getID3::VERSION, SQLITE3_TEXT);
		$result = $stmt->execute();
		list($version) = $result->fetchArray();
		if ($version != getID3::VERSION) { // Check version number and clear cache if changed
			$this->clear_cache();
		}
		parent::__construct();
	}

	/**
	 * close the database connection
	 */
	public function __destruct() {
		$db=$this->db;
		$db->close();
	}

	/**
	 * clear the cache
	 *
	 * @return SQLite3Result
	 */
	private function clear_cache() {
		$db = $this->db;
		$sql = $this->getQuery('delete_cache');
		$db->exec($sql);
		$sql = $this->getQuery('set_version');
		$stmt = $db->prepare($sql);
		$stmt->bindValue(':filename', getID3::VERSION, SQLITE3_TEXT);
		$stmt->bindValue(':dirname', getID3::VERSION, SQLITE3_TEXT);
		$stmt->bindValue(':val', getID3::VERSION, SQLITE3_TEXT);
		return $stmt->execute();
	}

	/**
	 * analyze file and cache them, if cached pull from the db
	 *
	 * @param string  $filename
	 * @param integer $filesize
	 * @param string  $original_filename
	 *
	 * @return mixed|false
	 */
	public function analyze($filename, $filesize=null, $original_filename='') {
		if (!file_exists($filename)) {
			return false;
		}
		// items to track for caching
		$filetime = filemtime($filename);
		$filesize_real = filesize($filename);
		// this will be saved for a quick directory lookup of analized files
		// ... why do 50 seperate sql quries when you can do 1 for the same result
		$dirname  = dirname($filename);
		// Lookup file
		$db = $this->db;
		$sql = $this->getQuery('get_id3_data');
		$stmt = $db->prepare($sql);
		$stmt->bindValue(':filename', $filename,      SQLITE3_TEXT);
		$stmt->bindValue(':filesize', $filesize_real, SQLITE3_INTEGER);
		$stmt->bindValue(':filetime', $filetime,      SQLITE3_INTEGER);
		$res = $stmt->execute();
		list($result) = $res->fetchArray();
		if (count($result) > 0 ) {
			return unserialize(base64_decode($result));
		}
		// if it hasn't been analyzed before, then do it now
		$analysis = parent::analyze($filename, $filesize, $original_filename);
		// Save result
		$sql = $this->getQuery('cache_file');
		$stmt = $db->prepare($sql);
		$stmt->bindValue(':filename', $filename,                           SQLITE3_TEXT);
		$stmt->bindValue(':dirname',  $dirname,                            SQLITE3_TEXT);
		$stmt->bindValue(':filesize', $filesize_real,                      SQLITE3_INTEGER);
		$stmt->bindValue(':filetime', $filetime,                           SQLITE3_INTEGER);
		$stmt->bindValue(':atime',    time(),                              SQLITE3_INTEGER);
		$stmt->bindValue(':val',      base64_encode(serialize($analysis)), SQLITE3_TEXT);
		$res = $stmt->execute();
		return $analysis;
	}

	/**
	 * create data base table
	 * this is almost the same as MySQL, with the exception of the dirname being added
	 *
	 * @return bool
	 */
	private function create_table() {
		$db = $this->db;
		$sql = $this->getQuery('make_table');
		return $db->exec($sql);
	}

	/**
	 * get cached directory
	 *
	 * This function is not in the MySQL extention, it's ment to speed up requesting multiple files
	 * which is ideal for podcasting, playlists, etc.
	 *
	 * @param string $dir directory to search the cache database for
	 *
	 * @return array return an array of matching id3 data
	 */
	public function get_cached_dir($dir) {
		$db = $this->db;
		$rows = array();
		$sql = $this->getQuery('get_cached_dir');
		$stmt = $db->prepare($sql);
		$stmt->bindValue(':dirname', $dir, SQLITE3_TEXT);
		$res = $stmt->execute();
		while ($row=$res->fetchArray()) {
			$rows[] = unserialize(base64_decode($row));
		}
		return $rows;
	}

	/**
	 * returns NULL if query is not found
	 *
	 * @param string $name
	 *
	 * @return null|string
	 */
	public function getQuery($name)
	{
		switch ($name) {
			case 'version_check':
				return "SELECT val FROM $this->table WHERE filename = :filename AND filesize = '-1' AND filetime = '-1' AND analyzetime = '-1'";
				break;
			case 'delete_cache':
				return "DELETE FROM $this->table";
				break;
			case 'set_version':
				return "INSERT INTO $this->table (filename, dirname, filesize, filetime, analyzetime, val) VALUES (:filename, :dirname, -1, -1, -1, :val)";
				break;
			case 'get_id3_data':
				return "SELECT val FROM $this->table WHERE filename = :filename AND filesize = :filesize AND filetime = :filetime";
				break;
			case 'cache_file':
				return "INSERT INTO $this->table (filename, dirname, filesize, filetime, analyzetime, val) VALUES (:filename, :dirname, :filesize, :filetime, :atime, :val)";
				break;
			case 'make_table':
				return "CREATE TABLE IF NOT EXISTS $this->table (filename VARCHAR(255) DEFAULT '', dirname VARCHAR(255) DEFAULT '', filesize INT(11) DEFAULT '0', filetime INT(11) DEFAULT '0', analyzetime INT(11) DEFAULT '0', val text, PRIMARY KEY (filename, filesize, filetime))";
				break;
			case 'get_cached_dir':
				return "SELECT val FROM $this->table WHERE dirname = :dirname";
				break;
			default:
				return null;
		}
	}

	/**
	* use the magical __get() for sql queries
	*
	* access as easy as $this->{case name}, returns NULL if query is not found
	*
	* @param string $name
	*
	* @return string
	* @deprecated use getQuery() instead
	*/
	public function __get($name) {
		return $this->getQuery($name);
	}

}
