<?php
/* Copyright (C) 2001      Fabien Seisen        <seisen@linuxfr.org>
 * Copyright (C) 2002-2005 Rodolphe Quiedeville <rodolphe@quiedeville.org>
 * Copyright (C) 2004-2011 Laurent Destailleur  <eldy@users.sourceforge.net>
 * Copyright (C) 2006      Andre Cianfarani     <acianfa@free.fr>
 * Copyright (C) 2005-2009 Regis Houssin        <regis.houssin@capnetworks.com>
 * Copyright (C) 2015      Raphaël Doursenaud   <rdoursenaud@gpcsolutions.fr>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

/**
 *	\file       htdocs/core/db/sqlite.class.php
 *	\brief      Class file to manage Dolibarr database access for a SQLite database
 */

require_once DOL_DOCUMENT_ROOT .'/core/db/DoliDB.class.php';

/**
 *	Class to manage Dolibarr database access for a SQLite database
 */
class DoliDBSqlite3 extends DoliDB
{
    //! Database type
    public $type='sqlite3';
    //! Database label
    const LABEL='Sqlite3';
    //! Version min database
    const VERSIONMIN='3.0.0';
	/** @var SQLite3Result Resultset of last query */
	private $_results;

    const WEEK_MONDAY_FIRST=1;
    const WEEK_YEAR = 2;
    const WEEK_FIRST_WEEKDAY=4;


    /**
	 *	Constructor.
	 *	This create an opened connexion to a database server and eventually to a database
     *
	 *	@param      string	$type		Type of database (mysql, pgsql...)
	 *	@param	    string	$host		Address of database server
	 *	@param	    string	$user		Nom de l'utilisateur autorise
	 *	@param	    string	$pass		Mot de passe
	 *	@param	    string	$name		Nom de la database
	 *	@param	    int		$port		Port of database server
     */
    function __construct($type, $host, $user, $pass, $name='', $port=0)
    {
        global $conf;

        // Note that having "static" property for "$forcecharset" and "$forcecollate" will make error here in strict mode, so they are not static
        if (! empty($conf->db->character_set)) $this->forcecharset=$conf->db->character_set;
        if (! empty($conf->db->dolibarr_main_db_collation)) $this->forcecollate=$conf->db->dolibarr_main_db_collation;

        $this->database_user=$user;
        $this->database_host=$host;
        $this->database_port=$port;

        $this->transaction_opened=0;

        //print "Name DB: $host,$user,$pass,$name<br>";

        /*if (! function_exists("sqlite_query"))
        {
            $this->connected = false;
            $this->ok = false;
            $this->error="Sqlite PHP functions for using Sqlite driver are not available in this version of PHP. Try to use another driver.";
            dol_syslog(get_class($this)."::DoliDBSqlite3 : Sqlite PHP functions for using Sqlite driver are not available in this version of PHP. Try to use another driver.",LOG_ERR);
            return $this->ok;
        }*/

        /*if (! $host)
        {
            $this->connected = false;
            $this->ok = false;
            $this->error=$langs->trans("ErrorWrongHostParameter");
            dol_syslog(get_class($this)."::DoliDBSqlite3 : Erreur Connect, wrong host parameters",LOG_ERR);
            return $this->ok;
        }*/

        // Essai connexion serveur
        // We do not try to connect to database, only to server. Connect to database is done later in constrcutor
        $this->db = $this->connect($host, $user, $pass, $name, $port);

        if ($this->db)
        {
            $this->connected = true;
            $this->ok = true;
            $this->database_selected = true;
            $this->database_name = $name;

            $this->addCustomFunction('IF');
            $this->addCustomFunction('MONTH');
            $this->addCustomFunction('CURTIME');
            $this->addCustomFunction('CURDATE');
            $this->addCustomFunction('WEEK', 1);
            $this->addCustomFunction('WEEK', 2);
            $this->addCustomFunction('WEEKDAY');
            $this->addCustomFunction('date_format');
            //$this->db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        }
        else
        {
            // host, login ou password incorrect
            $this->connected = false;
            $this->ok = false;
            $this->database_selected = false;
            $this->database_name = '';
            //$this->error=sqlite_connect_error();
            dol_syslog(get_class($this)."::DoliDBSqlite3 : Error Connect ".$this->error,LOG_ERR);
        }

        return $this->ok;
    }


    /**
     *  Convert a SQL request in Mysql syntax to native syntax
     *
     *  @param     string	$line   SQL request line to convert
     *  @param     string	$type	Type of SQL order ('ddl' for insert, update, select, delete or 'dml' for create, alter...)
     *  @return    string   		SQL request line converted
     */
    static function convertSQLFromMysql($line,$type='ddl')
    {
        // Removed empty line if this is a comment line for SVN tagging
        if (preg_match('/^--\s\$Id/i',$line)) {
            return '';
        }
        // Return line if this is a comment
        if (preg_match('/^#/i',$line) || preg_match('/^$/i',$line) || preg_match('/^--/i',$line))
        {
            return $line;
        }
        if ($line != "")
        {
            if ($type == 'auto')
            {
              if (preg_match('/ALTER TABLE/i',$line)) $type='dml';
              else if (preg_match('/CREATE TABLE/i',$line)) $type='dml';
              else if (preg_match('/DROP TABLE/i',$line)) $type='dml';
            }

            if ($type == 'dml')
            {
                $line=preg_replace('/\s/',' ',$line);   // Replace tabulation with space

                // we are inside create table statement so lets process datatypes
                if (preg_match('/(ISAM|innodb)/i',$line)) { // end of create table sequence
                    $line=preg_replace('/\)[\s\t]*type[\s\t]*=[\s\t]*(MyISAM|innodb);/i',');',$line);
                    $line=preg_replace('/\)[\s\t]*engine[\s\t]*=[\s\t]*(MyISAM|innodb);/i',');',$line);
                    $line=preg_replace('/,$/','',$line);
                }

                // Process case: "CREATE TABLE llx_mytable(rowid integer NOT NULL AUTO_INCREMENT PRIMARY KEY,code..."
                if (preg_match('/[\s\t\(]*(\w*)[\s\t]+int.*auto_increment/i',$line,$reg)) {
                    $newline=preg_replace('/([\s\t\(]*)([a-zA-Z_0-9]*)[\s\t]+int.*auto_increment[^,]*/i','\\1 \\2 integer PRIMARY KEY AUTOINCREMENT',$line);
                    //$line = "-- ".$line." replaced by --\n".$newline;
                    $line=$newline;
                }

                // tinyint type conversion
                $line=str_replace('tinyint','smallint',$line);

                // nuke unsigned
                $line=preg_replace('/(int\w+|smallint)\s+unsigned/i','\\1',$line);

                // blob -> text
                $line=preg_replace('/\w*blob/i','text',$line);

                // tinytext/mediumtext -> text
                $line=preg_replace('/tinytext/i','text',$line);
                $line=preg_replace('/mediumtext/i','text',$line);

                // change not null datetime field to null valid ones
                // (to support remapping of "zero time" to null
                $line=preg_replace('/datetime not null/i','datetime',$line);
                $line=preg_replace('/datetime/i','timestamp',$line);

                // double -> numeric
                $line=preg_replace('/^double/i','numeric',$line);
                $line=preg_replace('/(\s*)double/i','\\1numeric',$line);
                // float -> numeric
                $line=preg_replace('/^float/i','numeric',$line);
                $line=preg_replace('/(\s*)float/i','\\1numeric',$line);

                // unique index(field1,field2)
                if (preg_match('/unique index\s*\((\w+\s*,\s*\w+)\)/i',$line))
                {
                    $line=preg_replace('/unique index\s*\((\w+\s*,\s*\w+)\)/i','UNIQUE\(\\1\)',$line);
                }

                // We remove end of requests "AFTER fieldxxx"
                $line=preg_replace('/AFTER [a-z0-9_]+/i','',$line);

                // We remove start of requests "ALTER TABLE tablexxx" if this is a DROP INDEX
                $line=preg_replace('/ALTER TABLE [a-z0-9_]+ DROP INDEX/i','DROP INDEX',$line);

                // Translate order to rename fields
                if (preg_match('/ALTER TABLE ([a-z0-9_]+) CHANGE(?: COLUMN)? ([a-z0-9_]+) ([a-z0-9_]+)(.*)$/i',$line,$reg))
                {
                    $line = "-- ".$line." replaced by --\n";
                    $line.= "ALTER TABLE ".$reg[1]." RENAME COLUMN ".$reg[2]." TO ".$reg[3];
                }

                // Translate order to modify field format
                if (preg_match('/ALTER TABLE ([a-z0-9_]+) MODIFY(?: COLUMN)? ([a-z0-9_]+) (.*)$/i',$line,$reg))
                {
                    $line = "-- ".$line." replaced by --\n";
                    $newreg3=$reg[3];
                    $newreg3=preg_replace('/ DEFAULT NULL/i','',$newreg3);
                    $newreg3=preg_replace('/ NOT NULL/i','',$newreg3);
                    $newreg3=preg_replace('/ NULL/i','',$newreg3);
                    $newreg3=preg_replace('/ DEFAULT 0/i','',$newreg3);
                    $newreg3=preg_replace('/ DEFAULT \'[0-9a-zA-Z_@]*\'/i','',$newreg3);
                    $line.= "ALTER TABLE ".$reg[1]." ALTER COLUMN ".$reg[2]." TYPE ".$newreg3;
                    // TODO Add alter to set default value or null/not null if there is this in $reg[3]
                }

                // alter table add primary key (field1, field2 ...) -> We create a unique index instead as dynamic creation of primary key is not supported
                // ALTER TABLE llx_dolibarr_modules ADD PRIMARY KEY pk_dolibarr_modules (numero, entity);
                if (preg_match('/ALTER\s+TABLE\s*(.*)\s*ADD\s+PRIMARY\s+KEY\s*(.*)\s*\((.*)$/i',$line,$reg))
                {
                    $line = "-- ".$line." replaced by --\n";
                    $line.= "CREATE UNIQUE INDEX ".$reg[2]." ON ".$reg[1]."(".$reg[3];
                }

                // Translate order to drop foreign keys
                // ALTER TABLE llx_dolibarr_modules DROP FOREIGN KEY fk_xxx;
                if (preg_match('/ALTER\s+TABLE\s*(.*)\s*DROP\s+FOREIGN\s+KEY\s*(.*)$/i',$line,$reg))
                {
                    $line = "-- ".$line." replaced by --\n";
                    $line.= "ALTER TABLE ".$reg[1]." DROP CONSTRAINT ".$reg[2];
                }

                // alter table add [unique] [index] (field1, field2 ...)
                // ALTER TABLE llx_accountingaccount ADD INDEX idx_accountingaccount_fk_pcg_version (fk_pcg_version)
                if (preg_match('/ALTER\s+TABLE\s*(.*)\s*ADD\s+(UNIQUE INDEX|INDEX|UNIQUE)\s+(.*)\s*\(([\w,\s]+)\)/i',$line,$reg))
                {
                    $fieldlist=$reg[4];
                    $idxname=$reg[3];
                    $tablename=$reg[1];
                    $line = "-- ".$line." replaced by --\n";
                    $line.= "CREATE ".(preg_match('/UNIQUE/',$reg[2])?'UNIQUE ':'')."INDEX ".$idxname." ON ".$tablename." (".$fieldlist.")";
                }
                if (preg_match('/ALTER\s+TABLE\s*(.*)\s*ADD\s+CONSTRAINT\s+(.*)\s*FOREIGN\s+KEY\s*\(([\w,\s]+)\)\s*REFERENCES\s+(\w+)\s*\(([\w,\s]+)\)/i',$line, $reg)) {
                    // Pour l'instant les contraintes ne sont pas créées
                    dol_syslog(get_class().'::query line emptied');
                    $line = 'SELECT 0;';

                }

                //if (preg_match('/rowid\s+.*\s+PRIMARY\s+KEY,/i', $line)) {
                    //preg_replace('/(rowid\s+.*\s+PRIMARY\s+KEY\s*,)/i', '/* \\1 */', $line);
                //}
            }

            // Delete using criteria on other table must not declare twice the deleted table
            // DELETE FROM tabletodelete USING tabletodelete, othertable -> DELETE FROM tabletodelete USING othertable
            if (preg_match('/DELETE FROM ([a-z_]+) USING ([a-z_]+), ([a-z_]+)/i',$line,$reg))
            {
				if ($reg[1] == $reg[2])	// If same table, we remove second one
                {
                    $line=preg_replace('/DELETE FROM ([a-z_]+) USING ([a-z_]+), ([a-z_]+)/i','DELETE FROM \\1 USING \\3', $line);
                }
            }

            // Remove () in the tables in FROM if one table
            $line=preg_replace('/FROM\s*\((([a-z_]+)\s+as\s+([a-z_]+)\s*)\)/i','FROM \\1',$line);
            //print $line."\n";

            // Remove () in the tables in FROM if two table
            $line=preg_replace('/FROM\s*\(([a-z_]+\s+as\s+[a-z_]+)\s*,\s*([a-z_]+\s+as\s+[a-z_]+\s*)\)/i','FROM \\1, \\2',$line);
            //print $line."\n";

            // Remove () in the tables in FROM if two table
            $line=preg_replace('/FROM\s*\(([a-z_]+\s+as\s+[a-z_]+)\s*,\s*([a-z_]+\s+as\s+[a-z_]+\s*),\s*([a-z_]+\s+as\s+[a-z_]+\s*)\)/i','FROM \\1, \\2, \\3',$line);
            //print $line."\n";

            //print "type=".$type." newline=".$line."<br>\n";
        }

        return $line;
    }

    /**
	 *	Select a database
     *
	 *	@param	    string	$database	Name of database
	 *	@return	    boolean  		    true if OK, false if KO
     */
    function select_db($database)
    {
        dol_syslog(get_class($this)."::select_db database=".$database, LOG_DEBUG);
	    // FIXME: sqlite_select_db() does not exist
        return sqlite_select_db($this->db,$database);
    }


    /**
	 *	Connexion to server
     *
	 *	@param	    string	$host		database server host
	 *	@param	    string	$login		login
	 *	@param	    string	$passwd		password
	 *	@param		string	$name		name of database (not used for mysql, used for pgsql)
	 *	@param		integer	$port		Port of database server
	 *	@return		SQLite3				Database access handler
	 *	@see		close
     */
    function connect($host, $login, $passwd, $name, $port=0)
    {
        global $main_data_dir;

        dol_syslog(get_class($this)."::connect name=".$name,LOG_DEBUG);

        $dir=$main_data_dir;
        if (empty($dir)) $dir=DOL_DATA_ROOT;
        // With sqlite, port must be in connect parameters
        //if (! $newport) $newport=3306;
        $database_name = $dir.'/database_'.$name.'.sdb';
        try {
            /*** connect to SQLite database ***/
            //$this->db = new PDO("sqlite:".$dir.'/database_'.$name.'.sdb');
			$this->db = new SQLite3($database_name);
            //$this->db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        }
        catch(Exception $e)
        {
            $this->error=  self::LABEL.' '.$e->getMessage().' current dir='.$database_name;
            return '';
        }

        //print "Resultat fonction connect: ".$this->db;
        return $this->db;
    }


    /**
	 *	Return version of database server
     *
	 *	@return	        string      Version string
     */
    function getVersion()
    {
    	$tmp=$this->db->version();
        return $tmp['versionString'];
    }

    /**
     *	Return version of database client driver
     *
     *	@return	        string      Version string
     */
    function getDriverInfo()
    {
        return 'sqlite3 php driver';
    }


    /**
     *  Close database connexion
     *
     *  @return     bool     True if disconnect successfull, false otherwise
     *  @see        connect
     */
    function close()
    {
        if ($this->db)
        {
            if ($this->transaction_opened > 0) dol_syslog(get_class($this)."::close Closing a connection with an opened transaction depth=".$this->transaction_opened,LOG_ERR);
            $this->connected=false;
            $this->db->close();
            unset($this->db);    // Clean this->db
            return true;
        }
        return false;
    }

    /**
     *  Execute a SQL request and return the resultset
     *
     * 	@param	string	$query			SQL query string
     * 	@param	int		$usesavepoint	0=Default mode, 1=Run a savepoint before and a rollbock to savepoint if error (this allow to have some request with errors inside global transactions).
     * 									Note that with Mysql, this parameter is not used as Myssql can already commit a transaction even if one request is in error, without using savepoints.
     *  @param  string	$type           Type of SQL order ('ddl' for insert, update, select, delete or 'dml' for create, alter...)
     *	@return	SQLite3Result			Resultset of answer
     */
    function query($query,$usesavepoint=0,$type='auto')
    {
        $ret=null;
        $query = trim($query);
        $this->error = 0;

        // Convert MySQL syntax to SQLite syntax
        if (preg_match('/ALTER\s+TABLE\s*(.*)\s*ADD\s+CONSTRAINT\s+(.*)\s*FOREIGN\s+KEY\s*\(([\w,\s]+)\)\s*REFERENCES\s+(\w+)\s*\(([\w,\s]+)\)/i',$query, $reg)) {
            // Ajout d'une clef étrangère à la table
            // procédure de remplacement de la table pour ajouter la contrainte
            // Exemple : ALTER TABLE llx_adherent ADD CONSTRAINT adherent_fk_soc FOREIGN KEY (fk_soc) REFERENCES llx_societe (rowid)
            // -> CREATE TABLE ( ... ,CONSTRAINT adherent_fk_soc FOREIGN KEY (fk_soc) REFERENCES llx_societe (rowid))
            $foreignFields = $reg[5];
            $foreignTable = $reg[4];
            $localfields = $reg[3];
            $constraintname=trim($reg[2]);
            $tablename=trim($reg[1]);

            $descTable = $this->db->querySingle("SELECT sql FROM sqlite_master WHERE name='" . $tablename . "'");

            // 1- Renommer la table avec un nom temporaire
            $this->query('ALTER TABLE ' . $tablename . ' RENAME TO tmp_' . $tablename);

            // 2- Recréer la table avec la contrainte ajoutée

            // on bricole la requete pour ajouter la contrainte
            $descTable = substr($descTable, 0, strlen($descTable) - 1);
            $descTable .= ", CONSTRAINT " . $constraintname . " FOREIGN KEY (" . $localfields . ") REFERENCES " .$foreignTable . "(" . $foreignFields . ")";

            // fermeture de l'instruction
            $descTable .= ')';

            // Création proprement dite de la table
            $this->query($descTable);

            // 3- Transférer les données
            $this->query('INSERT INTO ' . $tablename . ' SELECT * FROM tmp_' . $tablename);

            // 4- Supprimer la table temporaire
            $this->query('DROP TABLE tmp_' . $tablename);

            // dummy statement
            $query="SELECT 0";

        } else {
            $query=$this->convertSQLFromMysql($query,$type);
        }
        //print "After convertSQLFromMysql:\n".$query."<br>\n";

        dol_syslog('sql='.$query, LOG_DEBUG);

        // Ordre SQL ne necessitant pas de connexion a une base (exemple: CREATE DATABASE)
        try {
            //$ret = $this->db->exec($query);
            $ret = $this->db->query($query);        // $ret is a Sqlite3Result
            if ($ret) {
                $ret->queryString = $query;
            }
        }
        catch(Exception $e)
        {
            $this->error=$this->db->lastErrorMsg();
        }

        if (! preg_match("/^COMMIT/i",$query) && ! preg_match("/^ROLLBACK/i",$query))
        {
            // Si requete utilisateur, on la sauvegarde ainsi que son resultset
            if (! is_object($ret) || $this->error)
            {
                $this->lastqueryerror = $query;
                $this->lasterror = $this->error();
                $this->lasterrno = $this->errno();

                dol_syslog(get_class($this)."::query SQL Error query: ".$query, LOG_ERR);

                $errormsg = get_class($this)."::query SQL Error message: ".$this->lasterror;

                if (preg_match('/[0-9]/',$this->lasterrno)) {
                    $errormsg .= ' ('.$this->lasterrno.')';
                }

                dol_syslog($errormsg, LOG_ERR);
            }
            $this->lastquery=$query;
            $this->_results = $ret;
        }

        return $ret;
    }

    /**
     *	Renvoie la ligne courante (comme un objet) pour le curseur resultset
     *
     *	@param	SQLite3Result	$resultset  Curseur de la requete voulue
     *	@return	false|object				Object result line or false if KO or end of cursor
     */
    function fetch_object($resultset)
    {
        // Si le resultset n'est pas fourni, on prend le dernier utilise sur cette connexion
        if (! is_object($resultset)) { $resultset=$this->_results; }
        //return $resultset->fetch(PDO::FETCH_OBJ);
        $ret = $resultset->fetchArray(SQLITE3_ASSOC);
        if ($ret) {
            return (object) $ret;
        }
		return false;
    }


    /**
     *	Return datas as an array
     *
     *	@param	SQLite3Result	$resultset  Resultset of request
     *	@return	false|array					Array or false if KO or end of cursor
     */
    function fetch_array($resultset)
    {
        // If resultset not provided, we take the last used by connexion
        if (! is_object($resultset)) { $resultset=$this->_results; }
        //return $resultset->fetch(PDO::FETCH_ASSOC);
        $ret = $resultset->fetchArray(SQLITE3_ASSOC);
	    return $ret;
    }

    /**
     *	Return datas as an array
     *
     *	@param	SQLite3Result	$resultset  Resultset of request
     *	@return	false|array					Array or false if KO or end of cursor
     */
    function fetch_row($resultset)
    {
        // If resultset not provided, we take the last used by connexion
        if (! is_bool($resultset))
        {
            if (! is_object($resultset)) { $resultset=$this->_results; }
            return $resultset->fetchArray(SQLITE3_NUM);
        }
        else
        {
            // si le curseur est un booleen on retourne la valeur 0
            return false;
        }
    }

    /**
     *	Return number of lines for result of a SELECT
     *
     *	@param	SQLite3Result	$resultset  Resulset of requests
     *	@return int		    			Nb of lines
     *	@see    affected_rows
     */
    function num_rows($resultset)
    {
	    // FIXME: SQLite3Result does not have a queryString member

        // If resultset not provided, we take the last used by connexion
        if (! is_object($resultset)) { $resultset=$this->_results; }
        if (preg_match("/^SELECT/i", $resultset->queryString)) {
            return $this->db->querySingle("SELECT count(*) FROM (" . $resultset->queryString . ") q");
        }
        return 0;
    }

    /**
     *	Return number of lines for result of a SELECT
     *
     *	@param	SQLite3Result	$resultset  Resulset of requests
     *	@return int		    			Nb of lines
     *	@see    affected_rows
     */
    function affected_rows($resultset)
    {
	    // FIXME: SQLite3Result does not have a queryString member

        // If resultset not provided, we take the last used by connexion
        if (! is_object($resultset)) { $resultset=$this->_results; }
        if (preg_match("/^SELECT/i", $resultset->queryString)) {
            return $this->num_rows($resultset);
        }
        // mysql necessite un link de base pour cette fonction contrairement
        // a pqsql qui prend un resultset
        return $this->db->changes();
    }


    /**
	 *	Free last resultset used.
     *
	 *	@param  SQLite3Result	$resultset   Curseur de la requete voulue
	 *	@return	void
     */
    function free($resultset=null)
    {
        // If resultset not provided, we take the last used by connexion
        if (! is_object($resultset)) { $resultset=$this->_results; }
        // Si resultset en est un, on libere la memoire
        if ($resultset && is_object($resultset)) $resultset->finalize();
    }

    /**
	 *	Escape a string to insert data
     *
	 *  @param	string	$stringtoencode		String to escape
	 *  @return	string						String escaped
     */
    function escape($stringtoencode)
    {
        return Sqlite3::escapeString($stringtoencode);
    }

    /**
     *	Renvoie le code erreur generique de l'operation precedente.
     *
     *	@return	string		Error code (Exemples: DB_ERROR_TABLE_ALREADY_EXISTS, DB_ERROR_RECORD_ALREADY_EXISTS...)
     */
    function errno()
    {
        if (! $this->connected) {
            // Si il y a eu echec de connexion, $this->db n'est pas valide.
            return 'DB_ERROR_FAILED_TO_CONNECT';
        }
        else {
            // Constants to convert error code to a generic Dolibarr error code
            /*$errorcode_map = array(
            1004 => 'DB_ERROR_CANNOT_CREATE',
            1005 => 'DB_ERROR_CANNOT_CREATE',
            1006 => 'DB_ERROR_CANNOT_CREATE',
            1007 => 'DB_ERROR_ALREADY_EXISTS',
            1008 => 'DB_ERROR_CANNOT_DROP',
            1025 => 'DB_ERROR_NO_FOREIGN_KEY_TO_DROP',
            1044 => 'DB_ERROR_ACCESSDENIED',
            1046 => 'DB_ERROR_NODBSELECTED',
            1048 => 'DB_ERROR_CONSTRAINT',
            'HY000' => 'DB_ERROR_TABLE_ALREADY_EXISTS',
            1051 => 'DB_ERROR_NOSUCHTABLE',
            1054 => 'DB_ERROR_NOSUCHFIELD',
            1060 => 'DB_ERROR_COLUMN_ALREADY_EXISTS',
            1061 => 'DB_ERROR_KEY_NAME_ALREADY_EXISTS',
            1062 => 'DB_ERROR_RECORD_ALREADY_EXISTS',
            1064 => 'DB_ERROR_SYNTAX',
            1068 => 'DB_ERROR_PRIMARY_KEY_ALREADY_EXISTS',
            1075 => 'DB_ERROR_CANT_DROP_PRIMARY_KEY',
            1091 => 'DB_ERROR_NOSUCHFIELD',
            1100 => 'DB_ERROR_NOT_LOCKED',
            1136 => 'DB_ERROR_VALUE_COUNT_ON_ROW',
            1146 => 'DB_ERROR_NOSUCHTABLE',
            1216 => 'DB_ERROR_NO_PARENT',
            1217 => 'DB_ERROR_CHILD_EXISTS',
            1451 => 'DB_ERROR_CHILD_EXISTS'
            );

            if (isset($errorcode_map[$this->db->errorCode()]))
            {
                return $errorcode_map[$this->db->errorCode()];
            }*/
            $errno=$this->db->lastErrorCode();
			if ($errno=='HY000' || $errno == 0)
            {
                if (preg_match('/table.*already exists/i',$this->error))     return 'DB_ERROR_TABLE_ALREADY_EXISTS';
                elseif (preg_match('/index.*already exists/i',$this->error)) return 'DB_ERROR_KEY_NAME_ALREADY_EXISTS';
                elseif (preg_match('/syntax error/i',$this->error))          return 'DB_ERROR_SYNTAX';
            }
            if ($errno=='23000')
            {
                if (preg_match('/column.* not unique/i',$this->error))       return 'DB_ERROR_RECORD_ALREADY_EXISTS';
                elseif (preg_match('/PRIMARY KEY must be unique/i',$this->error)) return 'DB_ERROR_RECORD_ALREADY_EXISTS';
            }
            if ($errno > 1) {
                // TODO Voir la liste des messages d'erreur
            }

            return ($errno?'DB_ERROR_'.$errno:'0');
        }
    }

    /**
     *	Renvoie le texte de l'erreur mysql de l'operation precedente.
     *
     *	@return	string	Error text
     */
    function error()
    {
        if (! $this->connected) {
            // Si il y a eu echec de connexion, $this->db n'est pas valide pour sqlite_error.
            return 'Not connected. Check setup parameters in conf/conf.php file and your sqlite version';
        }
        else {
            return $this->error;
        }
    }

    /**
     * Get last ID after an insert INSERT
     *
	 * @param   string	$tab    	Table name concerned by insert. Ne sert pas sous MySql mais requis pour compatibilite avec Postgresql
	 * @param	string	$fieldid	Field name
	 * @return  int     			Id of row
     */
    function last_insert_id($tab,$fieldid='rowid')
    {
        return $this->db->lastInsertRowId();
    }

    /**
     *  Encrypt sensitive data in database
     *  Warning: This function includes the escape, so it must use direct value
     *
     *  @param  string  $fieldorvalue   Field name or value to encrypt
     *  @param	int		$withQuotes     Return string with quotes
     *  @return string          		XXX(field) or XXX('value') or field or 'value'
     */
    function encrypt($fieldorvalue, $withQuotes=0)
    {
        global $conf;

        // Type of encryption (2: AES (recommended), 1: DES , 0: no encryption)
        $cryptType = ($conf->db->dolibarr_main_db_encryption?$conf->db->dolibarr_main_db_encryption:0);

        //Encryption key
        $cryptKey = (!empty($conf->db->dolibarr_main_db_cryptkey)?$conf->db->dolibarr_main_db_cryptkey:'');

        $return = ($withQuotes?"'":"").$this->escape($fieldorvalue).($withQuotes?"'":"");

        if ($cryptType && !empty($cryptKey))
        {
            if ($cryptType == 2)
            {
                $return = 'AES_ENCRYPT('.$return.',\''.$cryptKey.'\')';
            }
            else if ($cryptType == 1)
            {
                $return = 'DES_ENCRYPT('.$return.',\''.$cryptKey.'\')';
            }
        }

        return $return;
    }

    /**
     *	Decrypt sensitive data in database
     *
     *	@param	string	$value			Value to decrypt
     * 	@return	string					Decrypted value if used
     */
    function decrypt($value)
    {
        global $conf;

        // Type of encryption (2: AES (recommended), 1: DES , 0: no encryption)
        $cryptType = ($conf->db->dolibarr_main_db_encryption?$conf->db->dolibarr_main_db_encryption:0);

        //Encryption key
        $cryptKey = (!empty($conf->db->dolibarr_main_db_cryptkey)?$conf->db->dolibarr_main_db_cryptkey:'');

        $return = $value;

        if ($cryptType && !empty($cryptKey))
        {
            if ($cryptType == 2)
            {
                $return = 'AES_DECRYPT('.$value.',\''.$cryptKey.'\')';
            }
            else if ($cryptType == 1)
            {
                $return = 'DES_DECRYPT('.$value.',\''.$cryptKey.'\')';
            }
        }

        return $return;
    }


    /**
     * Return connexion ID
     *
	 * @return	        string      Id connexion
     */
    function DDLGetConnectId()
    {
        return '?';
    }


    /**
	 *	Create a new database
	 *	Do not use function xxx_create_db (xxx=mysql, ...) as they are deprecated
	 *	We force to create database with charset this->forcecharset and collate this->forcecollate
     *
	 *	@param	string	$database		Database name to create
	 * 	@param	string	$charset		Charset used to store data
	 * 	@param	string	$collation		Charset used to sort data
	 * 	@param	string	$owner			Username of database owner
	 * 	@return	SQLite3Result   		resource defined if OK, null if KO
     */
    function DDLCreateDb($database,$charset='',$collation='',$owner='')
    {
        if (empty($charset))   $charset=$this->forcecharset;
        if (empty($collation)) $collation=$this->forcecollate;

        // ALTER DATABASE dolibarr_db DEFAULT CHARACTER SET latin DEFAULT COLLATE latin1_swedish_ci
        $sql = 'CREATE DATABASE '.$database;
        $sql.= ' DEFAULT CHARACTER SET '.$charset.' DEFAULT COLLATE '.$collation;

        dol_syslog($sql,LOG_DEBUG);
        $ret=$this->query($sql);
        if (! $ret)
        {
            // We try again for compatibility with Mysql < 4.1.1
            $sql = 'CREATE DATABASE '.$database;
            $ret=$this->query($sql);
            dol_syslog($sql,LOG_DEBUG);
        }
        return $ret;
    }

    /**
     *  List tables into a database
     *
	 *  @param	string		$database	Name of database
	 *  @param	string		$table		Name of table filter ('xxx%')
	 *  @return	array					List of tables in an array
     */
    function DDLListTables($database, $table='')
    {
        $listtables=array();

        $like = '';
        if ($table) $like = "LIKE '".$table."'";
        $sql="SHOW TABLES FROM ".$database." ".$like.";";
        //print $sql;
        $result = $this->query($sql);
        while($row = $this->fetch_row($result))
        {
            $listtables[] = $row[0];
        }
        return $listtables;
    }

    /**
	 *	List information of columns into a table.
     *
	 *	@param	string	$table		Name of table
	 *	@return	array				Tableau des informations des champs de la table
	 *	TODO modify for sqlite
     */
    function DDLInfoTable($table)
    {
        $infotables=array();

        $sql="SHOW FULL COLUMNS FROM ".$table.";";

        dol_syslog($sql,LOG_DEBUG);
        $result = $this->query($sql);
        while($row = $this->fetch_row($result))
        {
            $infotables[] = $row;
        }
        return $infotables;
    }

    /**
	 *	Create a table into database
     *
	 *	@param	    string	$table 			Nom de la table
	 *	@param	    array	$fields 		Tableau associatif [nom champ][tableau des descriptions]
	 *	@param	    string	$primary_key 	Nom du champ qui sera la clef primaire
	 *	@param	    string	$type 			Type de la table
	 *	@param	    array	$unique_keys 	Tableau associatifs Nom de champs qui seront clef unique => valeur
	 *	@param	    array	$fulltext_keys	Tableau des Nom de champs qui seront indexes en fulltext
	 *	@param	    array	$keys 			Tableau des champs cles noms => valeur
	 *	@return	    int						<0 if KO, >=0 if OK
     */
    function DDLCreateTable($table,$fields,$primary_key,$type,$unique_keys=null,$fulltext_keys=null,$keys=null)
    {
	    // FIXME: $fulltext_keys parameter is unused

        // cles recherchees dans le tableau des descriptions (fields) : type,value,attribute,null,default,extra
        // ex. : $fields['rowid'] = array('type'=>'int','value'=>'11','null'=>'not null','extra'=> 'auto_increment');
        $sql = "create table ".$table."(";
        $i=0;
        foreach($fields as $field_name => $field_desc)
        {
            $sqlfields[$i] = $field_name." ";
            $sqlfields[$i]  .= $field_desc['type'];
            if( preg_match("/^[^\s]/i",$field_desc['value']))
            $sqlfields[$i]  .= "(".$field_desc['value'].")";
            else if( preg_match("/^[^\s]/i",$field_desc['attribute']))
            $sqlfields[$i]  .= " ".$field_desc['attribute'];
            else if( preg_match("/^[^\s]/i",$field_desc['default']))
            {
                if(preg_match("/null/i",$field_desc['default']))
                $sqlfields[$i]  .= " default ".$field_desc['default'];
                else
                $sqlfields[$i]  .= " default '".$field_desc['default']."'";
            }
            else if( preg_match("/^[^\s]/i",$field_desc['null']))
            $sqlfields[$i]  .= " ".$field_desc['null'];

            else if( preg_match("/^[^\s]/i",$field_desc['extra']))
            $sqlfields[$i]  .= " ".$field_desc['extra'];
            $i++;
        }
        if($primary_key != "")
        $pk = "primary key(".$primary_key.")";

        if(is_array($unique_keys))
        {
            $i = 0;
            foreach($unique_keys as $key => $value)
            {
                $sqluq[$i] = "UNIQUE KEY '".$key."' ('".$value."')";
                $i++;
            }
        }
        if(is_array($keys))
        {
            $i = 0;
            foreach($keys as $key => $value)
            {
                $sqlk[$i] = "KEY ".$key." (".$value.")";
                $i++;
            }
        }
        $sql .= implode(',',$sqlfields);
        if($primary_key != "")
        $sql .= ",".$pk;
        if(is_array($unique_keys))
        $sql .= ",".implode(',',$sqluq);
        if(is_array($keys))
        $sql .= ",".implode(',',$sqlk);
        $sql .=") type=".$type;

        dol_syslog($sql,LOG_DEBUG);
        if(! $this -> query($sql))
            return -1;
        return 1;
    }

    /**
	 *	Return a pointer of line with description of a table or field
     *
	 *	@param	string		$table	Name of table
	 *	@param	string		$field	Optionnel : Name of field if we want description of field
	 *	@return	SQLite3Result		Resource
     */
    function DDLDescTable($table,$field="")
    {
        $sql="DESC ".$table." ".$field;

        dol_syslog(get_class($this)."::DDLDescTable ".$sql,LOG_DEBUG);
        $this->_results = $this->query($sql);
        return $this->_results;
    }

    /**
	 *	Create a new field into table
     *
	 *	@param	string	$table 				Name of table
	 *	@param	string	$field_name 		Name of field to add
	 *	@param	string	$field_desc 		Tableau associatif de description du champ a inserer[nom du parametre][valeur du parametre]
	 *	@param	string	$field_position 	Optionnel ex.: "after champtruc"
	 *	@return	int							<0 if KO, >0 if OK
     */
    function DDLAddField($table,$field_name,$field_desc,$field_position="")
    {
        // cles recherchees dans le tableau des descriptions (field_desc) : type,value,attribute,null,default,extra
        // ex. : $field_desc = array('type'=>'int','value'=>'11','null'=>'not null','extra'=> 'auto_increment');
        $sql= "ALTER TABLE ".$table." ADD ".$field_name." ";
        $sql.= $field_desc['type'];
        if(preg_match("/^[^\s]/i",$field_desc['value']))
        if (! in_array($field_desc['type'],array('date','datetime')))
        {
            $sql.= "(".$field_desc['value'].")";
        }
        if(preg_match("/^[^\s]/i",$field_desc['attribute']))
        $sql.= " ".$field_desc['attribute'];
        if(preg_match("/^[^\s]/i",$field_desc['null']))
        $sql.= " ".$field_desc['null'];
        if(preg_match("/^[^\s]/i",$field_desc['default']))
        {
            if(preg_match("/null/i",$field_desc['default']))
            $sql.= " default ".$field_desc['default'];
            else
            $sql.= " default '".$field_desc['default']."'";
        }
        if(preg_match("/^[^\s]/i",$field_desc['extra']))
        $sql.= " ".$field_desc['extra'];
        $sql.= " ".$field_position;

        dol_syslog(get_class($this)."::DDLAddField ".$sql,LOG_DEBUG);
        if(! $this->query($sql))
        {
            return -1;
        }
        return 1;
    }

    /**
	 *	Update format of a field into a table
     *
	 *	@param	string	$table 				Name of table
	 *	@param	string	$field_name 		Name of field to modify
	 *	@param	string	$field_desc 		Array with description of field format
	 *	@return	int							<0 if KO, >0 if OK
     */
    function DDLUpdateField($table,$field_name,$field_desc)
    {
        $sql = "ALTER TABLE ".$table;
        $sql .= " MODIFY COLUMN ".$field_name." ".$field_desc['type'];
        if ($field_desc['type'] == 'tinyint' || $field_desc['type'] == 'int' || $field_desc['type'] == 'varchar') {
            $sql.="(".$field_desc['value'].")";
        }

        dol_syslog(get_class($this)."::DDLUpdateField ".$sql,LOG_DEBUG);
        if (! $this->query($sql))
            return -1;
        return 1;
    }

    /**
	 *	Drop a field from table
     *
	 *	@param	string	$table 			Name of table
	 *	@param	string	$field_name 	Name of field to drop
	 *	@return	int						<0 if KO, >0 if OK
     */
    function DDLDropField($table,$field_name)
    {
        $sql= "ALTER TABLE ".$table." DROP COLUMN `".$field_name."`";
        dol_syslog(get_class($this)."::DDLDropField ".$sql,LOG_DEBUG);
        if (! $this->query($sql))
        {
            $this->error=$this->lasterror();
            return -1;
        }
        return 1;
    }


    /**
	 * 	Create a user and privileges to connect to database (even if database does not exists yet)
     *
	 *	@param	string	$dolibarr_main_db_host 		Ip serveur
	 *	@param	string	$dolibarr_main_db_user 		Nom user a creer
	 *	@param	string	$dolibarr_main_db_pass 		Mot de passe user a creer
	 *	@param	string	$dolibarr_main_db_name		Database name where user must be granted
	 *	@return	int									<0 if KO, >=0 if OK
     */
    function DDLCreateUser($dolibarr_main_db_host,$dolibarr_main_db_user,$dolibarr_main_db_pass,$dolibarr_main_db_name)
    {
        $sql = "INSERT INTO user ";
        $sql.= "(Host,User,password,Select_priv,Insert_priv,Update_priv,Delete_priv,Create_priv,Drop_priv,Index_Priv,Alter_priv,Lock_tables_priv)";
        $sql.= " VALUES ('".$this->escape($dolibarr_main_db_host)."','".$this->escape($dolibarr_main_db_user)."',password('".addslashes($dolibarr_main_db_pass)."')";
        $sql.= ",'Y','Y','Y','Y','Y','Y','Y','Y','Y')";

        dol_syslog(get_class($this)."::DDLCreateUser", LOG_DEBUG);	// No sql to avoid password in log
        $resql=$this->query($sql);
        if (! $resql)
        {
            return -1;
        }

        $sql = "INSERT INTO db ";
        $sql.= "(Host,Db,User,Select_priv,Insert_priv,Update_priv,Delete_priv,Create_priv,Drop_priv,Index_Priv,Alter_priv,Lock_tables_priv)";
        $sql.= " VALUES ('".$this->escape($dolibarr_main_db_host)."','".$this->escape($dolibarr_main_db_name)."','".addslashes($dolibarr_main_db_user)."'";
        $sql.= ",'Y','Y','Y','Y','Y','Y','Y','Y','Y')";

        dol_syslog(get_class($this)."::DDLCreateUser", LOG_DEBUG);
        $resql=$this->query($sql);
        if (! $resql)
        {
            return -1;
        }

        $sql="FLUSH Privileges";

        dol_syslog(get_class($this)."::DDLCreateUser", LOG_DEBUG);
        $resql=$this->query($sql);
        if (! $resql)
        {
            return -1;
        }
        return 1;
    }

    /**
	 *	Return charset used to store data in database
     *
	 *	@return		string		Charset
     */
    function getDefaultCharacterSetDatabase()
    {
        return 'UTF-8';
    }

    /**
	 *	Return list of available charset that can be used to store data in database
     *
	 *	@return		array		List of Charset
     */
    function getListOfCharacterSet()
    {
        $liste = array();
        $i=0;
        $liste[$i]['charset'] = 'UTF-8';
        $liste[$i]['description'] = 'UTF-8';
        return $liste;
    }

    /**
	 *	Return collation used in database
     *
	 *	@return		string		Collation value
     */
    function getDefaultCollationDatabase()
    {
        return 'UTF-8';
    }

    /**
	 *	Return list of available collation that can be used for database
     *
	 *	@return		array		List of Collation
     */
    function getListOfCollation()
    {
        $liste = array();
        $i=0;
        $liste[$i]['charset'] = 'UTF-8';
        $liste[$i]['description'] = 'UTF-8';
        return $liste;
    }

    /**
	 *	Return full path of dump program
     *
	 *	@return		string		Full path of dump program
     */
    function getPathOfDump()
    {
	    // FIXME: not for SQLite
        $fullpathofdump='/pathtomysqldump/mysqldump';

        $resql=$this->query('SHOW VARIABLES LIKE \'basedir\'');
        if ($resql)
        {
            $liste=$this->fetch_array($resql);
            $basedir=$liste['Value'];
            $fullpathofdump=$basedir.(preg_match('/\/$/',$basedir)?'':'/').'bin/mysqldump';
        }
        return $fullpathofdump;
    }

    /**
	 *	Return full path of restore program
     *
	 *	@return		string		Full path of restore program
     */
    function getPathOfRestore()
    {
	    // FIXME: not for SQLite
        $fullpathofimport='/pathtomysql/mysql';

        $resql=$this->query('SHOW VARIABLES LIKE \'basedir\'');
        if ($resql)
        {
            $liste=$this->fetch_array($resql);
            $basedir=$liste['Value'];
            $fullpathofimport=$basedir.(preg_match('/\/$/',$basedir)?'':'/').'bin/mysql';
        }
        return $fullpathofimport;
    }

    /**
     * Return value of server parameters
     *
	 * @param	string	$filter		Filter list on a particular value
	 * @return	array				Array of key-values (key=>value)
     */
    function getServerParametersValues($filter='')
    {
        $result=array();
        static $pragmas;
        if (! isset($pragmas)) {
            // Définition de la liste des pragmas utilisés qui ne retournent qu'une seule valeur
            // indépendante de la base de données.
            // cf. http://www.sqlite.org/pragma.html
            $pragmas = array(
                'application_id', 'auto_vacuum', 'automatic_index', 'busy_timeout', 'cache_size',
                'cache_spill', 'case_sensitive_like', 'checkpoint_fullsync', 'collation_list',
				'compile_options', 'data_version',	/*'database_list',*/
                'defer_foreign_keys', 'encoding', 'foreign_key_check', 'freelist_count',
                'full_column_names', 'fullsync', 'ingore_check_constraints', 'integrity_check',
                'journal_mode', 'journal_size_limit', 'legacy_file_format', 'locking_mode',
                'max_page_count', 'page_count', 'page_size', 'parser_trace',
                'query_only', 'quick_check', 'read_uncommitted', 'recursive_triggers',
                'reverse_unordered_selects', 'schema_version', 'user_version',
                'secure_delete', 'short_column_names', 'shrink_memory', 'soft_heap_limit',
                'synchronous', 'temp_store', /*'temp_store_directory',*/ 'threads',
                'vdbe_addoptrace', 'vdbe_debug', 'vdbe_listing', 'vdbe_trace',
                'wal_autocheckpoint',
            );
        }

        // TODO prendre en compte le filtre
        foreach($pragmas as $var) {
            $sql = "PRAGMA $var";
            $resql=$this->query($sql);
            if ($resql)
            {
                $obj = $this->fetch_row($resql);
                //dol_syslog(get_class($this)."::select_db getServerParametersValues $var=". print_r($obj, true), LOG_DEBUG);
                $result[$var] = $obj[0];
            }
            else {
                // TODO Récupérer le message
                $result[$var] = 'FAIL';
            }
        }
        return $result;
    }

    /**
     * Return value of server status
     *
	 * @param	string	$filter		Filter list on a particular value
	 * @return  array				Array of key-values (key=>value)
     */
    function getServerStatusValues($filter='')
    {
        $result=array();
        /*
        $sql='SHOW STATUS';
        if ($filter) $sql.=" LIKE '".$this->escape($filter)."'";
        $resql=$this->query($sql);
        if ($resql)
        {
            while ($obj=$this->fetch_object($resql)) $result[$obj->Variable_name]=$obj->Value;
        }
         */

        return $result;
    }

    /**
     * Permet le chargement d'une fonction personnalisee dans le moteur de base de donnees.
     * Note: le nom de la fonction personnalisee est prefixee par 'db'. La fonction doit être
     * statique et publique. Le nombre de parametres est determine automatiquement.
     *
     * @param 	string 	$name 			Le nom de la fonction a definir dans Sqlite
     * @param	int		$arg_count		Arg count
     * @return	void
     */
    private function addCustomFunction($name, $arg_count = -1)
    {
        if ($this->db)
        {
        	$newname=preg_replace('/_/','',$name);
            $localname = __CLASS__ . '::' . 'db' . $newname;
            $reflectClass = new ReflectionClass(__CLASS__);
            $reflectFunction = $reflectClass->getMethod('db' . $newname);
            if ($arg_count < 0) {
                $arg_count = $reflectFunction->getNumberOfParameters();
            }
            if (!$this->db->createFunction($name, $localname, $arg_count))
            {
                $this->error = "unable to create custom function '$name'";
            }
        }
    }

    /**
     * Cette fonction est l'equivalent de la fonction MONTH de MySql.
     *
     * @param 	string 		$date		Date
     * @return 	string
     */
    public static function dbMONTH($date)
    {
        return date('n', strtotime($date));
    }

    /**
     *  calcule du numéro de semaine
     *
     *  @param 	string	 	$date		Date
     *  @param 	int 		$mode		Mode
     *  @return	string
     */
    public static function dbWEEK($date, $mode = 0)
    {
        $arr = date_parse($date);
        $calc_year = 0;
        return self::calc_week($arr['year'], $arr['month'], $arr['day'], self::week_mode($mode), $calc_year);
    }

    /**
     *  db_CURDATE
     *
     *  @return	string
     */
    public static function dbCURDATE() {
        return date('Y-m-d');
    }

    /**
     *  db_CURTIME
     *
     *  @return	string
     */
    public static function dbCURTIME() {
        return date('H:i:s');
    }

    /**
     *  dbWEEKDAY
     *
     *  @param	int		$date			Date
     *  @return	double
     */
    public static function dbWEEKDAY($date) {
        $arr = date_parse($date);
        return self::calc_weekday(self::calc_daynr($arr['year'], $arr['month'], $arr['day']), 0);

    }

    /**
     * Cette fonction est l'equivelent de la fonction date_format de MySQL.
	 * @staticvar string $mysql_replacement	Les symboles formatage a remplacer
	 *
     * @param 	string $date 	la date dans un format ISO
     * @param 	string $format 	la chaine de formatage
     * @return 	string 			La date formatee.
     */
    public static function dbdateformat($date, $format)
    {
        static $mysql_replacement;
        if (! isset($mysql_replacement)) {
            $mysql_replacement = array(
                '%' => '%',
                'a' => 'D',
                'b' => 'M',
                'c' => 'n',
                'D' => 'jS',
                'd' => 'd',
                'e' => 'j',
                'f' => 'u',
                'H' => 'H',
                'h' => 'h',
                'I' => 'h',
                'i' => 'i',
                'k' => 'H',
                'l' => 'g',
                'M' => 'F',
                'm' => 'm',
                'p' => 'A',
                'r' => 'h:i:s A',
                'S' => 's',
                's' => 's',
                'T' => 'H:i:s',
                'W' => 'l',
                'w' => 'w',
                'Y' => 'Y',
                'y' => 'y',
            );
        }

        $fmt = '';
        $lg = strlen($format);
        $state = 0;
        $timestamp = strtotime($date);
        $yday = date('z', $timestamp);
        $month = (integer) date("n", $timestamp);
        $year = (integer) date("Y", $timestamp);
        $day = (integer) date("d", $timestamp);
        for($idx = 0; $idx < $lg; ++$idx) {
            $char = $format[$idx];
            if ($state == 0) {
                if ($char == '%') {
                    $state = 1;
                } else {
                    $fmt .= $char;
                }
            }
            elseif ($state == 1) {
                if (array_key_exists($char, $mysql_replacement)) {
                    $fmt .= $mysql_replacement[$char];
                } else {
                    $calc_year = 0;
                    switch ($char) {
						case 'j':	// day of the year 001
                            $char = sprintf("%03d", $yday+1);
                            break;
                        case 'U': // mode 0: semaine 0 = premiere semaine complète qui commence un dimanche
                            $char = sprintf("%02d", self::calc_week($year, $month, $day, 4, $calc_year));
                            break;
                        case 'u': // mode 1: semaine 0 = première semaine de 4 jours. Début le dimanche
                            $char = sprintf("%02d", self::calc_week($year, $month, $day, 1, $calc_year));
                            break;
                        case 'V': // mode 2: semaine 1 = premiere semaine complète qui commence un dimanche
                            $char = sprintf("%02d", self::calc_week($year, $month, $day, 6, $calc_year));
                            break;
                        case 'v':  // mode 3: semaine 1 = premiere semaine de 4 jours. Début le lundi
                            $char = sprintf("%02d", self::calc_week($year, $month, $day, 3, $calc_year));
                            break;
                        case 'X':
                            self::calc_week($year, $month, $day, 6, $calc_year);
                            $char = sprintf("%04d", $calc_year);
                            break;
                        case 'x':
                            self::calc_week($year, $month, $day, 3, $calc_year);
                            $char = sprintf("%04d", $calc_year);
                            break;
                    }
                    $fmt .= $char;
                }
                $state = 0;
            }
        }
        return date($fmt, strtotime($date));
    }


    /**
     * calc_daynr
     *
     * @param 	int 	$year		Year
     * @param 	int 	$month		Month
     * @param	int     $day 		Day
     * @return int Formatted date
     */
    private static function calc_daynr($year, $month, $day) {
        $y = $year;
        if ($y == 0 && $month == 0) return 0;
        $num = (365* $y + 31 * ($month - 1) + $day);
        if ($month <= 2) {
            $y--; }
        else {
            $num -= floor(($month * 4 + 23) / 10);
        }
        $temp = floor(($y / 100 + 1) * 3 / 4);
        return $num + floor($y / 4) - $temp;
    }

    /**
     * calc_weekday
     *
     * @param int	$daynr							???
     * @param bool	$sunday_first_day_of_week		???
     * @return int
     */
    private static function calc_weekday($daynr, $sunday_first_day_of_week) {
      $ret = floor(($daynr + 5 + ($sunday_first_day_of_week ? 1 : 0)) % 7);
      return $ret;
    }

    /**
     * calc_days_in_year
     *
     * @param 	string	$year		Year
     * @return	int					Nb of days in year
     */
    private static function calc_days_in_year($year)
    {
      return (($year & 3) == 0 && ($year%100 || ($year%400 == 0 && $year)) ? 366 : 365);
    }

    /**
     * week_mode
     *
     * @param 	string	$mode		Mode
     * @return	integer				Week format
     */
    private static function week_mode($mode) {
        $week_format= ($mode & 7);
        if (!($week_format & self::WEEK_MONDAY_FIRST)) {
            $week_format^= self::WEEK_FIRST_WEEKDAY;
        }
        return $week_format;
    }

	/**
	 * calc_week
	 *
	 * @param 	string	$year				Year
	 * @param 	string	$month				Month
	 * @param 	string	$day				Day
	 * @param 	string	$week_behaviour		Week behaviour
	 * @param 	string	$calc_year			???
	 * @return	string						???
	 */
    private static function calc_week($year, $month, $day, $week_behaviour, &$calc_year) {
        $daynr=self::calc_daynr($year,$month,$day);
        $first_daynr=self::calc_daynr($year,1,1);
        $monday_first= ($week_behaviour & self::WEEK_MONDAY_FIRST) ? 1 : 0;
        $week_year= ($week_behaviour & self::WEEK_YEAR) ? 1 : 0;
        $first_weekday= ($week_behaviour & self::WEEK_FIRST_WEEKDAY) ? 1 : 0;

        $weekday=self::calc_weekday($first_daynr, !$monday_first);
        $calc_year=$year;

        if ($month == 1 && $day <= 7-$weekday)
        {
            if (!$week_year && (($first_weekday && $weekday != 0) || (!$first_weekday && $weekday >= 4)))
                return 0;
            $week_year= 1;
            $calc_year--;
            $first_daynr-= ($days=self::calc_days_in_year($calc_year));
            $weekday= ($weekday + 53*7- $days) % 7;
      }

      if (($first_weekday && $weekday != 0) || (!$first_weekday && $weekday >= 4)) {
        $days= $daynr - ($first_daynr+ (7-$weekday));
      }
      else {
        $days= $daynr - ($first_daynr - $weekday);
      }

      if ($week_year && $days >= 52*7)
      {
        $weekday= ($weekday + self::calc_days_in_year($calc_year)) % 7;
        if ((!$first_weekday && $weekday < 4) || ($first_weekday && $weekday == 0))
        {
          $calc_year++;
          return 1;
        }
      }
      return floor($days/7+1);
    }

}

