<?php
// +----------------------------------------------------------------------+
// | PHP versions 4 and 5                                                 |
// +----------------------------------------------------------------------+
// | Copyright (c) 1998-2007 Manuel Lemos, Tomas V.V.Cox,                 |
// | Stig. S. Bakken, Lukas Smith                                         |
// | All rights reserved.                                                 |
// +----------------------------------------------------------------------+
// | MDB2 is a merge of PEAR DB and Metabases that provides a unified DB  |
// | API as well as database abstraction for PHP applications.            |
// | This LICENSE is in the BSD license style.                            |
// |                                                                      |
// | 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 Manuel Lemos, Tomas V.V.Cox, Stig. S. Bakken,    |
// | Lukas Smith nor the names of his 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      |
// | REGENTS 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.                                          |
// +----------------------------------------------------------------------+
// | Author: Lukas Smith <smith@pooteeweet.org>                           |
// +----------------------------------------------------------------------+
//
// $Id: Common.php,v 1.128 2007/11/09 20:54:58 quipo Exp $

require_once 'MDB2/LOB.php';

/**
 * @package  MDB2
 * @category Database
 * @author   Lukas Smith <smith@pooteeweet.org>
 */

/**
 * MDB2_Driver_Common: Base class that is extended by each MDB2 driver
 *
 * To load this module in the MDB2 object:
 * $mdb->loadModule('Datatype');
 *
 * @package MDB2
 * @category Database
 * @author Lukas Smith <smith@pooteeweet.org>
 */
class MDB2_Driver_Datatype_Common extends MDB2_Module_Common
{
    var $valid_default_values = array(
        'text'      => '',
        'boolean'   => true,
        'integer'   => 0,
        'decimal'   => 0.0,
        'float'     => 0.0,
        'timestamp' => '1970-01-01 00:00:00',
        'time'      => '00:00:00',
        'date'      => '1970-01-01',
        'clob'      => '',
        'blob'      => '',
    );

    /**
     * contains all LOB objects created with this MDB2 instance
     * @var array
     * @access protected
     */
    var $lobs = array();

    // }}}
    // {{{ getValidTypes()

    /**
     * Get the list of valid types
     *
     * This function returns an array of valid types as keys with the values
     * being possible default values for all native datatypes and mapped types
     * for custom datatypes.
     *
     * @return mixed array on success, a MDB2 error on failure
     * @access public
     */
    function getValidTypes()
    {
        $types = $this->valid_default_values;
        $db =& $this->getDBInstance();
        if (PEAR::isError($db)) {
            return $db;
        }
        if (!empty($db->options['datatype_map'])) {
            foreach ($db->options['datatype_map'] as $type => $mapped_type) {
                if (array_key_exists($mapped_type, $types)) {
                    $types[$type] = $types[$mapped_type];
                } elseif (!empty($db->options['datatype_map_callback'][$type])) {
                    $parameter = array('type' => $type, 'mapped_type' => $mapped_type);
                    $default =  call_user_func_array($db->options['datatype_map_callback'][$type], array(&$db, __FUNCTION__, $parameter));
                    $types[$type] = $default;
                }
            }
        }
        return $types;
    }

    // }}}
    // {{{ checkResultTypes()

    /**
     * Define the list of types to be associated with the columns of a given
     * result set.
     *
     * This function may be called before invoking fetchRow(), fetchOne()
     * fetchCole() and fetchAll() so that the necessary data type
     * conversions are performed on the data to be retrieved by them. If this
     * function is not called, the type of all result set columns is assumed
     * to be text, thus leading to not perform any conversions.
     *
     * @param array $types array variable that lists the
     *       data types to be expected in the result set columns. If this array
     *       contains less types than the number of columns that are returned
     *       in the result set, the remaining columns are assumed to be of the
     *       type text. Currently, the types clob and blob are not fully
     *       supported.
     * @return mixed MDB2_OK on success, a MDB2 error on failure
     * @access public
     */
    function checkResultTypes($types)
    {
        $types = is_array($types) ? $types : array($types);
        foreach ($types as $key => $type) {
            if (!isset($this->valid_default_values[$type])) {
                $db =& $this->getDBInstance();
                if (PEAR::isError($db)) {
                    return $db;
                }
                if (empty($db->options['datatype_map'][$type])) {
                    return $db->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
                        $type.' for '.$key.' is not a supported column type', __FUNCTION__);
                }
            }
        }
        return $types;
    }

    // }}}
    // {{{ _baseConvertResult()

    /**
     * General type conversion method
     *
     * @param mixed   $value reference to a value to be converted
     * @param string  $type  specifies which type to convert to
     * @param boolean $rtrim [optional] when TRUE [default], apply rtrim() to text
     * @return object an MDB2 error on failure
     * @access protected
     */
    function _baseConvertResult($value, $type, $rtrim = true)
    {
        switch ($type) {
        case 'text':
            if ($rtrim) {
                $value = rtrim($value);
            }
            return $value;
        case 'integer':
            return intval($value);
        case 'boolean':
            return !empty($value);
        case 'decimal':
            return $value;
        case 'float':
            return doubleval($value);
        case 'date':
            return $value;
        case 'time':
            return $value;
        case 'timestamp':
            return $value;
        case 'clob':
        case 'blob':
            $this->lobs[] = array(
                'buffer' => null,
                'position' => 0,
                'lob_index' => null,
                'endOfLOB' => false,
                'resource' => $value,
                'value' => null,
                'loaded' => false,
            );
            end($this->lobs);
            $lob_index = key($this->lobs);
            $this->lobs[$lob_index]['lob_index'] = $lob_index;
            return fopen('MDB2LOB://'.$lob_index.'@'.$this->db_index, 'r+');
        }

        $db =& $this->getDBInstance();
        if (PEAR::isError($db)) {
            return $db;
        }

        return $db->raiseError(MDB2_ERROR_INVALID, null, null,
            'attempt to convert result value to an unknown type :' . $type, __FUNCTION__);
    }

    // }}}
    // {{{ convertResult()

    /**
     * Convert a value to a RDBMS indipendent MDB2 type
     *
     * @param mixed   $value value to be converted
     * @param string  $type  specifies which type to convert to
     * @param boolean $rtrim [optional] when TRUE [default], apply rtrim() to text
     * @return mixed converted value
     * @access public
     */
    function convertResult($value, $type, $rtrim = true)
    {
        if (is_null($value)) {
            return null;
        }
        $db =& $this->getDBInstance();
        if (PEAR::isError($db)) {
            return $db;
        }
        if (!empty($db->options['datatype_map'][$type])) {
            $type = $db->options['datatype_map'][$type];
            if (!empty($db->options['datatype_map_callback'][$type])) {
                $parameter = array('type' => $type, 'value' => $value, 'rtrim' => $rtrim);
                return call_user_func_array($db->options['datatype_map_callback'][$type], array(&$db, __FUNCTION__, $parameter));
            }
        }
        return $this->_baseConvertResult($value, $type, $rtrim);
    }

    // }}}
    // {{{ convertResultRow()

    /**
     * Convert a result row
     *
     * @param array   $types
     * @param array   $row   specifies the types to convert to
     * @param boolean $rtrim [optional] when TRUE [default], apply rtrim() to text
     * @return mixed MDB2_OK on success, an MDB2 error on failure
     * @access public
     */
    function convertResultRow($types, $row, $rtrim = true)
    {
        $types = $this->_sortResultFieldTypes(array_keys($row), $types);
        foreach ($row as $key => $value) {
            if (empty($types[$key])) {
                continue;
            }
            $value = $this->convertResult($row[$key], $types[$key], $rtrim);
            if (PEAR::isError($value)) {
                return $value;
            }
            $row[$key] = $value;
        }
        return $row;
    }

    // }}}
    // {{{ _sortResultFieldTypes()

    /**
     * convert a result row
     *
     * @param array $types
     * @param array $row specifies the types to convert to
     * @param bool   $rtrim   if to rtrim text values or not
     * @return mixed MDB2_OK on success,  a MDB2 error on failure
     * @access public
     */
    function _sortResultFieldTypes($columns, $types)
    {
        $n_cols = count($columns);
        $n_types = count($types);
        if ($n_cols > $n_types) {
            for ($i= $n_cols - $n_types; $i >= 0; $i--) {
                $types[] = null;
            }
        }
        $sorted_types = array();
        foreach ($columns as $col) {
            $sorted_types[$col] = null;
        }
        foreach ($types as $name => $type) {
            if (array_key_exists($name, $sorted_types)) {
                $sorted_types[$name] = $type;
                unset($types[$name]);
            }
        }
        // if there are left types in the array, fill the null values of the
        // sorted array with them, in order.
        if (count($types)) {
            reset($types);
            foreach (array_keys($sorted_types) as $k) {
                if (is_null($sorted_types[$k])) {
                    $sorted_types[$k] = current($types);
                    next($types);
                }
            }
        }
        return $sorted_types;
    }

    // }}}
    // {{{ getDeclaration()

    /**
     * Obtain DBMS specific SQL code portion needed to declare
     * of the given type
     *
     * @param string $type type to which the value should be converted to
     * @param string  $name   name the field to be declared.
     * @param string  $field  definition of the field
     * @return string  DBMS specific SQL code portion that should be used to
     *                 declare the specified field.
     * @access public
     */
    function getDeclaration($type, $name, $field)
    {
        $db =& $this->getDBInstance();
        if (PEAR::isError($db)) {
            return $db;
        }

        if (!empty($db->options['datatype_map'][$type])) {
            $type = $db->options['datatype_map'][$type];
            if (!empty($db->options['datatype_map_callback'][$type])) {
                $parameter = array('type' => $type, 'name' => $name, 'field' => $field);
                return call_user_func_array($db->options['datatype_map_callback'][$type], array(&$db, __FUNCTION__, $parameter));
            }
            $field['type'] = $type;
        }

        if (!method_exists($this, "_get{$type}Declaration")) {
            return $db->raiseError(MDB2_ERROR_NOT_FOUND, null, null,
                'type not defined: '.$type, __FUNCTION__);
        }
        return $this->{"_get{$type}Declaration"}($name, $field);
    }

    // }}}
    // {{{ getTypeDeclaration()

    /**
     * Obtain DBMS specific SQL code portion needed to declare an text type