<?php
// Copyleft (C) 2004-20 BohwaZ, licence LGPL.

// mySQL DB Class
// v0.7.0 -- PDO wrapper

class DB_Exception extends Exception { }

class DB
{
    const FETCH_ASSOC = PDO::FETCH_ASSOC;
    const FETCH_NUM = PDO::FETCH_NUM;
    const FETCH_BOTH = PDO::FETCH_BOTH;

    protected static $connections = array();
    protected static $default_connection = false;

    public static function enableDebug()
    {
    }

    public static function disableDebug()
    {
    }

    public static function getDebugLog()
    {
    }

    public static function addConnection($id, $host, $user, $password, $database)
    {
        self::$connections[$id] = array(
            'host'  =>  $host,
            'user'  =>  $user,
            'password' => $password,
            'database' => $database,
            'link'  => false,
            'multiple' => 0,
            'encoding' => 'UTF8',
        );
        return true;
    }

    public static function setDefaultConnection($id)
    {
        self::$default_connection = $id;
    }

    public static function setEncoding($id, $encoding)
    {
        if (!isset(self::$connections[$id]))
            return false;

        self::$connections[$id]['encoding'] = $encoding;
    }

    public static function startMultipleQueries($connection=false)
    {
        $connection = self::getConnectionId($connection);

        self::$connections[$connection]['multiple'] += 1;
    }

    public static function endMultipleQueries($connection=false)
    {
        $connection = self::getConnectionId($connection);

        self::$connections[$connection]['multiple'] -= 1;

        if (empty(self::$connections[$connection]['multiple']))
            self::Close($connection);
    }

    public static function isMultiple($connection=false)
    {
        $connection = self::getConnectionId($connection);

        $is_multiple = (self::$connections[$connection]['multiple'] > 0) ? true : false;
        return $is_multiple;
    }

    public static function Connect($connection=false)
    {
        $connection = self::getConnectionId($connection);

        $config =& self::$connections[$connection];
        if (empty($config['host']) || empty($config['user']) || !isset($config['password']))
        {
            throw new DB_Exception("Invalid connection parameters for connection ".$connection.".");
        }

        $config['link'] = new PDO(sprintf('mysql:host=%s;dbname=%s;charset=%s', $config['host'], $config['database'], $config['encoding']), $config['user'], $config['password']);

        return true;
    }

    private static function getConnectionId($connection = false)
    {
        if (empty($connection))
        {
            if (!self::$default_connection)
                throw new DB_Exception("No connection selected and no default connection set.");

            $connection = self::$default_connection;
        }

        return $connection;
    }

    private static function &getLink($connection = false)
    {
        $connection = self::getConnectionId($connection);

        if (empty(self::$connections[$connection]['link']))
            self::Connect($connection);

        return self::$connections[$connection]['link'];
    }

    public static function query($query, $connection=false)
    {
        $connection = self::getConnectionId($connection);

        $pdo = self::getLink($connection);
        $result = $pdo->query($query);

        return $result;
    }

    public static function fetchRow($result, $fetch_mode=false)
    {
        if (!$fetch_mode)
            $fetch_mode = DB::FETCH_BOTH;

        return $result->fetch($fetch_mode);
    }

    public static function arrayQuery($query, $connection=false, $fetch_mode=false)
    {
        if (!$fetch_mode)
            $fetch_mode = DB::FETCH_BOTH;

        return self::query($query, $connection)->fetchAll($fetch_mode);
    }

    public static function unbufferedQuery($query, $connection=false)
    {
        return self::query($query, $connection);
    }

    public static function execQuery($query, $connection=false)
    {
        $connection = self::getConnectionId($connection);

        $lines = explode(';', $query);
        foreach ($lines as $line)
        {
            $line = trim($line);
            if (empty($line))
                continue;

            self::query($query, $connection);
        }

        return true;
    }

    public static function Close($connection=false)
    {
    }

    public static function q($query, $connection=false)
    {
        return self::query($query, $connection);
    }

    public static function aQuery($query, $connection=false, $fetch_mode=false)
    {
        return self::arrayQuery($query, $connection, $fetch_mode);
    }

    public static function uQuery($query, $connection=false)
    {
        return self::unbufferedQuery($query, $connection);
    }

    public static function eQuery($query)
    {
        return self::execQuery($query);
    }

    public static function getInsertId($connection=false)
    {
        return self::getLink($connection)->lastInsertId();
    }

    public static function escape($str, $connection=false)
    {
        if (is_array($str) || is_object($str))
            throw new DB_Exception("Trying to escape non-string variable of type ".gettype($str).": ".print_r($str, true));

        return substr(self::getLink($connection)->quote($str), 1, -1);
    }

    public static function e($str, $connection=false)
    {
        return self::escape($str, $connection);
    }

    public static function esc($str, $connection=false)
    {
        return self::escape($str, $connection);
    }
}