<?php
 /* -------------------------------------------------------------------------+
   | MySQLDriver.php                                                         |
   +-------------------------------------------------------------------------+
   | http://phpfunk.com                                                      |
   | Copyright (c) 2006 Salvador T. Pimienta                                 |
   | All Rights Reserved.                                                    |
   +-------------------------------------------------------------------------+
   | Redistribution and use in source and binary forms, with or without      |
   | modification, are permitted provided that the following conditions      | 
   | are met:                                                                |
   |  * Redistributions of source code must retain the above copyright       |
   | notice, this list of conditions and the following disclaimer.           |
   | * Redistributions in binary form must reproduce the above copyright     |
   | notice, this list of conditions and the following disclaimer in the     |
   | documentation and/or other materials provided with the distribution.    |
   | * Neither the name of the phpfunk.com nor the names of its              |
   | contributors may be used to endorse or promote products derived from    |
   | this software without specific prior written permission.                |
   |                                                                         |
   | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS     |
   | "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT       |
   | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR   |
   | A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT    |
   | OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,   |
   | SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT        |
   | LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,   |
   | DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY   |
   | THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT     |
   | (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE   |
   | OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.    |                               
   +----------------------------------------------------------------------- */
   
/**
 * @package persistance
 */
   
 /**
  * Driver class for mysql database for use with DBWrapper class
  */
class MySQLDriver {
    
    /**#@+
     * @access private
     */
    var $db;
    var $prepared;
    var $useQueryCache;
    var $queryCacheSize;
    /**#@-*/
    
    /**
     * @param bool $useQueryCache if you want to use mysql query cache
     * @param int $queryCacheSize size of query cache to use
     * Need to specify TRUE and non-zero cache size to actually use caching!
     */
    function MySQLDriver($useQueryCache=FALSE, $queryCacheSize=0) {
        $this->db = FALSE;
        $this->prepared = '';
        $this->useQueryCache = $useQueryCache;
        $this->queryCacheSize=$queryCacheSize;
    }
    
    function _enableQueryCache() {
        //do we have query cache?
        
        //set cache size
        return FALSE;
    }
    
    function _disableQueryCache() {
        return FALSE;
    }
    
    /**
     * @return bool TRUE upon successful connection
     * @param string $host
     * @param string $user
     * @param string $password
     * @param string $database
     */
    function connect($host, $user, $password, $database) {
        if( ( $db = mysql_connect( $host, $user, $password ) ) === FALSE ) {
            //failed to connect
            return FALSE;
        }
        if( mysql_select_db( $database, $db ) === FALSE ) {
            //failed to select $database
            return FALSE;
        }
        $this->db =& $db;
        if( $this->useQueryCache) {
            $this->_enableQueryCache();
        }
        return TRUE;
    }
    
    /**
     * @return void
     */
    function disconnect() {
        if( $this->isConnected() ) {
            mysql_close($this->db);
            $this->db = FALSE;
        }
    }
    
    /**
     * @return bool TRUE if connected
     */
    function isConnected() {
        return $this->db !== FALSE;
    }
    
    /**
     * Fetches a row or a single value from database.
     * @return mixed an array or scalar or FALSE on error
     * @param string $sql
     * @param mixed $args array
     */
    function selectOne( $sql, $args='', $FILE='', $LINE='' ) {
        if( $args && !is_array($args) ) {
            $args = array($args);
        }
        if( $args ) {
            $sql = $this->escapeString($sql, $args);
        }
        if( ($res = mysql_query($sql, $this->db)) === FALSE ) {
            //query failed!
            trigger_error(mysql_error() . $FILE . $LINE, E_USER_WARNING);
            return FALSE;
        }
        if( mysql_num_rows($res) == 0 ) {
            return NULL;  // no matches
        }
        $row = mysql_fetch_assoc($res);
        if( sizeof( $row ) > 1 ) {
           return DBWrapper::array_stripslashes($row); # array
        }
        list($value) = array_values($row);
        return DBWrapper::array_stripslashes($value);
    }
    
    /**
     * @return mixed array of rows or NULL if no matches or FALSE on error
     * @param string $sql
     * @param mixed $args array of values
     */
    function selectRows( $sql, $args='', $FILE='', $LINE='') {
        if( $args ) {
            if( !is_array($args)){
                $args = array($args);
            }
        }
        if( is_array($args) ) {
            $sql = $this->escapeString( $sql, $args );
        }
        if( ($res = mysql_query($sql, $this->db)) === FALSE ) {
            trigger_error(mysql_error() . $FILE . $LINE, E_USER_WARNING);
            return FALSE;
        }
        if( mysql_num_rows($res) == 0 ) {
            return NULL;
        }
        $data = array();
        while( $row = mysql_fetch_assoc($res)) {
            $data[] = $row;
        }
        mysql_free_result($res);
        return $data;
    }
    
    function selectColumn($sql, $args='', $FILE='', $LINE='') {
        if( $args ) {
            if( !is_array($args)){
                $args = array($args);
            }
        }
        if( is_array($args) ) {
            $sql = $this->escapeString( $sql, $args );
        }
        
        if( ($res = mysql_query($sql, $this->db)) === FALSE ) {
            trigger_error(mysql_error() . $FILE . $LINE, E_USER_WARNING);
            return FALSE;
        }
        if( mysql_num_rows($res) == 0 ){
            return null;
        }
        $rows = array();
        while( $row = mysql_fetch_row($res) ) {
            $rows[] = $row[0];
        }
        return $rows;
    }
    
    /**
     * Perform an sql query (non-select)
     * @return mixed number of rows affected or FALSE on error
     * @param string $sql
     * @param mixed $args single value or ordered array
     */
    function execute( $sql, $args='', $FILE='', $LINE='' ) {
        if( $args && !is_array($args) ) {
            $args = array($args);
        }
        if( $args ) {
            $sql = $this->escapeString( $sql, $args );
        }
        if( mysql_query($sql, $this->db) === FALSE ) {
            trigger_error(mysql_error() . " on $FILE at $LINE", E_USER_WARNING);
            return FALSE;
        }
        return mysql_affected_rows($this->db);
    }
    
    /**
     * Prepare a statement for execution w/ executeStatement()
     */
    function prepare($sql) {
        $this->prepared = $sql;
    }
    
    /**
     * Execute a prepared statement.
     * @param mixed $args scalar or ordered array
     * @return int num rows affected or FALSE on error
     */
    function executePrepared($args) {
        if( !$this->prepared ) {
            trigger_error( "Cannot execute because I don't have a prepared statement" );
            return FALSE;
        }
        if( !is_array($args) ) {
            $args = array($args);
        }
        return $this->execute($this->prepared, $args);
    }
    
    /**
     * @return mixed string message of last error of FALSE if no error
     */
    function lastError() {
        if( $this->isConnected()) {
            return mysql_error($this->db);
        }
        return FALSE; //no error
    }
    
    function lastInsertID() {
        return mysql_insert_id( $this->db);
    }
    
    /**
     * @return int num rows affected by last query
     */
    function affectedRows() {
        if( $this->isConnected()) {
            return mysql_affected_rows($this->db);
        }
        return 0;
    }
    
    /** 
     * @access private
     * @return string mysql real escaped string, also add 's around values
     * @todo BAD '?' is a valid SQL string used in searches!  Solution is
     * to make that part of query be one of the $args
     */
    function escapeString( $sql, $args ) {
        if(!is_array($args)) $args = array($args);
        $sqlArr = explode( '?', $sql, sizeof($args) );
        if( sizeof($sqlArr) != sizeof($args)) {
            trigger_error( "mismatch error: $sql {$args[0]}", E_USER_WARNING );
            return FALSE;
        }
        ksort($args);
        $sqlArr = explode( '?', $sql );
        for( $i=0; $i<sizeof($args); $i++ ) {
            $sqlArr[$i] .= "'".mysql_real_escape_string($args[$i])."'";
        }
        return implode( '', $sqlArr );
    }
    
    function startTransaction() {
        return mysql_query('START TRANSACTION');
    }
    
    function commit() {
        return mysql_query('COMMIT');
    }
    
    function rollback() {
        return mysql_query('ROLLBACK');
    }
    
    function escape($arg) {
        return mysql_real_escape_string($arg, $this->db);
    }
}

?>