<?php
/**
 * DbSimple_Mysql: MySQL database.
 * (C) Dk Lab, http://en.dklab.ru
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * See http://www.gnu.org/copyleft/lesser.html
 *
 * Placeholders end blobs are emulated.
 *
 * @author Dmitry Koterov, http://forum.dklab.ru/users/DmitryKoterov/
 * @author Konstantin Zhinko, http://forum.dklab.ru/users/KonstantinGinkoTit/
 *
 * @version 2.x $Id: Mysql.php 247 2008-08-18 21:17:08Z dk $
 */
//require_once __DIR__.'/Database.php';


/**
 * Database class for MySQL.
 */
class DbSimple_Mysql extends DbSimple_Database
{
	var $link;

	/**
	 * constructor(string $dsn)
	 * Connect to MySQL.
	 */
	function DbSimple_Mysql($dsn)
	{
		$this->dsn=$dsn;
		$this->_connect($dsn);
	}

	protected function _connect($dsn) {
		$connect = 'mysql_'.((isset($dsn['persist']) && $dsn['persist'])?'p':'').'connect';
		if (!is_callable($connect))
			return $this->_setLastError("-1", "MySQL extension is not loaded", $connect);

		//$mysql = mysql_connect(':/cloudsql/' . DB_HOST, DB_USER, DB_PASS);

		if ( !empty($dsn['socket']) && empty($dsn['host']) ) {
			// Socket connection
			$dsn['host'] = ':' . $dsn['socket'];
			unset($dsn['port']);
		}

		$ok = $this->link = @call_user_func($connect,
											$str = $dsn['host'] . (empty($dsn['port'])? "" : ":".$dsn['port']),
											$dsn['user'] = empty($dsn['user'])?'':$dsn['user'],
											$dsn['pass'] = empty($dsn['pass'])?'':$dsn['pass'],
											true
		);
		$this->_resetLastError();
		if (!$ok)
			if (!$ok) return $this->_setDbError('mysql_connect("' . $str . '", "' . $dsn['user'] . '")');
		$ok = @mysql_select_db(preg_replace('{^/}s', '', $dsn['path']), $this->link);
		if (!$ok)
			return $this->_setDbError('mysql_select_db()');
		mysql_query('SET NAMES '.(isset($dsn['enc'])?$dsn['enc']:'UTF8'));
	}

	protected function _performEscape($s, $isIdent=false)
	{
		// fix float type
		if (is_float($s)) {
			$s=str_replace(',', '.',$s);
		}
		if (!$isIdent)
			return "'" . mysql_real_escape_string($s, $this->link) . "'";
		else
			return "`" . str_replace('`', '``', $s) . "`";
	}


	protected function _performNewBlob($blobid=null)
	{
		return new DbSimple_Mysql_Blob($this, $blobid);
	}


	protected function _performGetBlobFieldNames($result)
	{
		$blobFields = array();
		for ($i=mysql_num_fields($result)-1; $i>=0; $i--)
		{
			$type = mysql_field_type($result, $i);
			if (stripos($type, "BLOB") !== false)
				$blobFields[] = mysql_field_name($result, $i);
		}
		return $blobFields;
	}


	protected function _performGetPlaceholderIgnoreRe()
	{
		return '
			"   (?> [^"\\\\]+|\\\\"|\\\\)*	"   |
			\'  (?> [^\'\\\\]+|\\\\\'|\\\\)* \'   |
			`   (?> [^`]+ | ``)*			  `   |   # backticks
			/\* .*?						  \*/	  # comments
		';
	}


	protected function _performTransaction($parameters=null)
	{
		return $this->query('BEGIN');
	}


	protected function _performCommit()
	{
		return $this->query('COMMIT');
	}


	protected function _performRollback()
	{
		return $this->query('ROLLBACK');
	}


	protected function _performTransformQuery(&$queryMain, $how)
	{
		// If we also need to calculate total number of found rows...
		switch ($how)
		{
			// Prepare total calculation (if possible)
			case 'CALC_TOTAL':
				$m = null;
				if (preg_match('/^(\s* SELECT)(.*)/six', $queryMain[0], $m))
					$queryMain[0] = $m[1] . ' SQL_CALC_FOUND_ROWS' . $m[2];
				return true;

			// Perform total calculation.
			case 'GET_TOTAL':
				// Built-in calculation available?
				$queryMain = array('SELECT FOUND_ROWS()');
				return true;
		}

		return false;
	}


	protected function _performQuery($queryMain)
	{
		$this->_lastQuery = $queryMain;
		$this->_expandPlaceholders($queryMain, false);
		$result = mysql_query($queryMain[0], $this->link);
		if ($result === false)
			return $this->_setDbError($queryMain[0]);
		if (!is_resource($result)) {
			if (preg_match('/^\s* INSERT \s+/six', $queryMain[0]))
			{
				if (!preg_match('/ON\s+DUPLICATE\s+KEY\s+UPDATE/six', $queryMain[0]))
				{
					$id=@mysql_insert_id($this->link);
					//if no autoincrement field
					if (!$id) return @mysql_affected_rows($this->link);
					else return @mysql_insert_id($this->link);
				}
				// INSERT queries return generated ID.
				return mysql_insert_id($this->link);
			}
			// Non-SELECT queries return number of affected rows, SELECT - resource.
			return mysql_affected_rows($this->link);
		}
		return $result;
	}


	protected function _performFetch($result)
	{
		$row = mysql_fetch_assoc($result);
		if (mysql_error()) return $this->_setDbError($this->_lastQuery);
		if ($row === false) return null;
		return $row;
	}


	protected function _setDbError($query)
	{
		if ($this->link) {
			return $this->_setLastError(mysql_errno($this->link), mysql_error($this->link), $query);
		} else {
			return $this->_setLastError(mysql_errno(), mysql_error(), $query);
		}
	}
}


class DbSimple_Mysql_Blob implements DbSimple_Blob
{
	// MySQL does not support separate BLOB fetching.
	private $blobdata = null;
	private $curSeek = 0;

	public function __construct(&$database, $blobdata=null)
	{
		$this->blobdata = $blobdata;
		$this->curSeek = 0;
	}

	public function read($len)
	{
		$p = $this->curSeek;
		$this->curSeek = min($this->curSeek + $len, strlen($this->blobdata));
		return substr($this->blobdata, $p, $len);
	}

	public function write($data)
	{
		$this->blobdata .= $data;
	}

	public function close()
	{
		return $this->blobdata;
	}

	public function length()
	{
		return strlen($this->blobdata);
	}
}
?>