<?php
/**
 * 
 * @author  Benjamin Gillissen <hide@address.com>
 * 
 *	**************************************************************

	Copyright (C) 2009  Benjamin Gillissen
	
	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 2
	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 at:
	http://www.gnu.org/copyleft/gpl.html

 *	**************************************************************
 */

class db_accessor {
	
	protected $DBRef;
	
	public function __construct($DBRef){
		$this->DBRef = $DBRef;
	}
	
	private function needrecode(){
		//TODO write db_accessor::needrecode method, need to know how to get charset informations.
		return FALSE;
	}
	
	private function recode($val){
		//TODO write db_accessor::recode method, rebuild from coreV2.
		if ( $this->needrecode() ){ return $val; }
		return $val;
	}
	
	protected function getconf(){
		if ( $conf = configs::get('db', $this->DBRef) ){
			if ( is_array($conf) ){
				return $conf;
			} else {
				return $this->parseDSN($conf);
			}
		}
		return FALSE;
	}
	
	public static function getvendor($DBRef){
		//mysql || oracle || odbc || sqlite || mssql
		$obj = new db_accessor($DBRef);
		$conf = $obj->getconf();
		unset($obj);
		if ( isset($conf['vendor']) ){
			return $conf['vendor'];
		}
		return FALSE;
	}
	
	
	//THX pear project :D
	private function parseDSN($dsn){
		if ( is_array($dsn) ){ return $dsn; }
        $parsed = array(
            'vendor'  => false,
            'dbsyntax' => false,
            'username' => false,
            'password' => false,
            'protocol' => false,
            'hostspec' => false,
            'port'     => false,
            'socket'   => false,
            'database' => false
        );

        // Find phptype and dbsyntax
        if (($pos = strpos($dsn, '://')) !== false) {
            $str = substr($dsn, 0, $pos);
            $dsn = substr($dsn, $pos + 3);
        } else {
            $str = $dsn;
            $dsn = NULL;
        }

        // Get phptype and dbsyntax
        // $str => phptype(dbsyntax)
        if (preg_match('|^(.+?)\((.*?)\)$|', $str, $arr)) {
            $parsed['vendor']  = $arr[1];
            $parsed['dbsyntax'] = (empty($arr[2])) ? $arr[1] : $arr[2];
        } else {
            $parsed['vendor']  = $str;
            $parsed['dbsyntax'] = $str;
        }

        if (empty($dsn)) {
            return $parsed;
        }

        // Get (if found): username and password
        // $dsn => username:hide@address.com+hostspec/database
        if (($at = strrpos($dsn,'@')) !== false) {
            $str = substr($dsn, 0, $at);
            $dsn = substr($dsn, $at + 1);
            if (($pos = strpos($str, ':')) !== false) {
                $parsed['username'] = rawurldecode(substr($str, 0, $pos));
                $parsed['password'] = rawurldecode(substr($str, $pos + 1));
            } else {
                $parsed['username'] = rawurldecode($str);
            }
        }

        // Find protocol and hostspec

        // $dsn => proto(proto_opts)/database
        if (preg_match('|^([^(]+)\((.*?)\)/?(.*?)$|', $dsn, $match)) {
            $proto       = $match[1];
            $proto_opts  = (!empty($match[2])) ? $match[2] : false;
            $dsn         = $match[3];

        // $dsn => protocol+hostspec/database (old format)
        } else {
            if (strpos($dsn, '+') !== false) {
                list($proto, $dsn) = explode('+', $dsn, 2);
            }
            if (strpos($dsn, '/') !== false) {
                list($proto_opts, $dsn) = explode('/', $dsn, 2);
            } else {
                $proto_opts = $dsn;
                $dsn = null;
            }
        }

        // process the different protocol options
        $parsed['protocol'] = (!empty($proto)) ? $proto : 'tcp';
        $proto_opts = rawurldecode($proto_opts);
        if ($parsed['protocol'] == 'tcp') {
            if (strpos($proto_opts, ':') !== false) {
                list($parsed['hostspec'], $parsed['port']) = explode(':', $proto_opts);
            } else {
                $parsed['hostspec'] = $proto_opts;
            }
        } elseif ($parsed['protocol'] == 'unix') {
            $parsed['socket'] = $proto_opts;
        }

        // Get dabase if any
        // $dsn => database
        if (!empty($dsn)) {
            // /database
            if (($pos = strpos($dsn, '?')) === false) {
                $parsed['database'] = $dsn;
            // /database?param1=value1&param2=value2
            } else {
                $parsed['database'] = substr($dsn, 0, $pos);
                $dsn = substr($dsn, $pos + 1);
                if (strpos($dsn, '&') !== false) {
                    $opts = explode('&', $dsn);
                } else { // database?param1=value1
                    $opts = array($dsn);
                }
                foreach ($opts as $opt) {
                    list($key, $value) = explode('=', $opt);
                    if (!isset($parsed[$key])) { // don't allow params overwrite
                        $parsed[$key] = rawurldecode($value);
                    }
                }
            }
        }

        return $parsed;
	}

}