<?php
/* -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
# ***** BEGIN LICENSE BLOCK *****
# This file is part of Plume Framework, a simple PHP Application Framework.
# Copyright (C) 2001-2007 Loic d'Anterroches and contributors.
#
# Plume Framework 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.
#
# Plume Framework 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 Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
#
# ***** END LICENSE BLOCK ***** */

/**
 * Database class.
 *
 * Depending of the parameters, the database object will connect to a MySQL
 * or SQLite database.
 */
class Pluf_DB
{

    /**
     * Get a database connection.
     */
    static function get($engine, $server, $database, $login, $password, 
                        $prefix, $debug=false, $version='')
    {
        $engine = 'Pluf_DB_'.$engine;
        $con = new $engine($login, $password, $server, $database,
                           $prefix, $debug, $version);
        return $con;
    }
}

/**
 * Get the default DB connection.
 *
 * The default database connection is defined in the configuration file
 * through the following configuration variables:
 * - db_login : Login to connect to the database
 * - db_password : Password to the database
 * - db_server : Name of the server
 * - db_database : Name of the database
 * - db_table_prefix : Prefix for the table names
 * - db_version : Version of the database engine
 * - db_engine : Engine for exampe 'MySQL', 'SQLite'
 *
 * Once the first connection is created the following calls to Pluf::db()
 * are getting the same connection.
 *
 */
function Pluf_DB_getConnection($extra=null)
{
    if (isset($GLOBALS['_PX_db']) && 
        (is_resource($GLOBALS['_PX_db']->con_id) or is_object($GLOBALS['_PX_db']->con_id))) {
        return $GLOBALS['_PX_db'];
    }
    $GLOBALS['_PX_db'] = Pluf_DB::get(Pluf::f('db_engine'), 
                                      Pluf::f('db_server'),    
                                      Pluf::f('db_database'),
                                      Pluf::f('db_login'), 
                                      Pluf::f('db_password'),
                                      Pluf::f('db_table_prefix'), 
                                      Pluf::f('debug'),
                                      Pluf::f('db_version'));
    return $GLOBALS['_PX_db'];
}

/**
 * Returns an array of default typecast and quoting for the database ORM.
 *
 * Foreach field type you need to provide an array with 2 functions,
 * the from_db, the to_db.
 *
 * $value = from_db($value);
 * $escaped_value = to_db($value, $dbobject); 
 *
 * $escaped_value is ready to be put in the SQL, that is if this is a
 * string, the value is quoted and escaped for example with SQLite:
 * 'my string'' is escaped' or with MySQL 'my string\' is escaped' the
 * starting ' and ending ' are included!
 *
 * @return array Default typecast.
 */
function Pluf_DB_defaultTypecast()
{
    return array(
                 'Pluf_DB_Field_Boolean' => 
                     array('Pluf_DB_BooleanFromDb', 'Pluf_DB_BooleanToDb'),
                 'Pluf_DB_Field_Date' => 
                     array('Pluf_DB_IdentityFromDb', 'Pluf_DB_IdentityToDb'),
                 'Pluf_DB_Field_Datetime' => 
                     array('Pluf_DB_IdentityFromDb', 'Pluf_DB_IdentityToDb'),
                 'Pluf_DB_Field_Email' => 
                     array('Pluf_DB_IdentityFromDb', 'Pluf_DB_IdentityToDb'),
                 'Pluf_DB_Field_File' => 
                     array('Pluf_DB_IdentityFromDb', 'Pluf_DB_IdentityToDb'),
                 'Pluf_DB_Field_Float' => 
                     array('Pluf_DB_IdentityFromDb', 'Pluf_DB_IdentityToDb'),
                 'Pluf_DB_Field_Foreignkey' => 
                     array('Pluf_DB_IntegerFromDb', 'Pluf_DB_IntegerToDb'),
                 'Pluf_DB_Field_Integer' => 
                     array('Pluf_DB_IntegerFromDb', 'Pluf_DB_IntegerToDb'),
                 'Pluf_DB_Field_Password' => 
                     array('Pluf_DB_IdentityFromDb', 'Pluf_DB_PasswordToDb'),
                 'Pluf_DB_Field_Sequence' => 
                     array('Pluf_DB_IntegerFromDb', 'Pluf_DB_IntegerToDb'),
                 'Pluf_DB_Field_Text' => 
                     array('Pluf_DB_IdentityFromDb', 'Pluf_DB_IdentityToDb'),
                 'Pluf_DB_Field_Varchar' => 
                     array('Pluf_DB_IdentityFromDb', 'Pluf_DB_IdentityToDb'),
                 'Pluf_DB_Field_Serialized' => 
                     array('Pluf_DB_SerializedFromDb', 'Pluf_DB_SerializedToDb'),
                 'Pluf_DB_Field_Compressed' => 
                     array('Pluf_DB_CompressedFromDb', 'Pluf_DB_CompressedToDb'),
                 );
}

/**
 * Identity function.
 *
 * @param mixed Value
 * @return mixed Value
 */
function Pluf_DB_IdentityFromDb($val)
{
    return $val;
}

/**
 * Identity function.
 *
 * @param mixed Value.
 * @param object Database handler.
 * @return string Ready to use for SQL.
 */
function Pluf_DB_IdentityToDb($val, $db)
{
    if (is_null($val)) {
        return 'NULL';
    }
    return $db->esc($val);
}

function Pluf_DB_SerializedFromDb($val)
{
    if ($val) {
        return unserialize($val);
    }
    return $val;
}

function Pluf_DB_SerializedToDb($val, $db)
{
    if (is_null($val)) {
        return 'NULL';
    }
    return $db->esc(serialize($val));
}

function Pluf_DB_CompressedFromDb($val)
{
    return ($val) ? gzinflate($val) : $val;
}

function Pluf_DB_CompressedToDb($val, $db)
{
    return (is_null($val)) ? 'NULL' : $db->esc(gzdeflate($val, 9));
}

function Pluf_DB_BooleanFromDb($val) {
    if ($val) {
        return true;
    }
    return false;
}

function Pluf_DB_BooleanToDb($val, $db) {
    if (is_null($val)) {
        return 'NULL';
    }
    if ($val) {
        return $db->esc('1');
    }
    return $db->esc('0');
}

function Pluf_DB_IntegerFromDb($val) {
    if (is_null($val)) return null;
    return (int) $val;
}

function Pluf_DB_IntegerToDb($val, $db) {
    if (is_null($val)) {
        return 'NULL';
    }
    return (string)(int)$val;
}

function Pluf_DB_PasswordToDb($val, $db) {
    $exp = explode(':', $val);
    if (in_array($exp[0], array('sha1', 'md5', 'crc32'))) {
        return $db->esc($val);
    }
    // We need to hash the value.
    $salt = Pluf_Utils::getRandomString(5);
    return $db->esc('sha1:'.$salt.':'.sha1($salt.$val));
}