<?php
/**
 * Copyright 2007 Maintainable Software, LLC
 * Copyright 2006-2008 The Horde Project (http://www.horde.org/)
 *
 * @author     Mike Naberezny <hide@address.com>
 * @author     Derek DeVries <hide@address.com>
 * @author     Chuck Hagenbuch <hide@address.com>
 * @license    http://opensource.org/licenses/bsd-license.php
 * @category   Horde
 * @package    Horde_Db
 * @subpackage Adapter
 */

/**
 * @author     Mike Naberezny <hide@address.com>
 * @author     Derek DeVries <hide@address.com>
 * @author     Chuck Hagenbuch <hide@address.com>
 * @license    http://opensource.org/licenses/bsd-license.php
 * @category   Horde
 * @package    Horde_Db
 * @subpackage Adapter
 */
class Horde_Db_Adapter_Mssql_Schema extends Horde_Db_Adapter_Abstract_Schema
{
    /*##########################################################################
    # Quoting
    ##########################################################################*/

    /**
     * @return  string
     */
    public function quoteColumnName($name)
    {
        return '[' . str_replace(']', ']]', $name) . ']';
    }


    /**
     */
    public function getTables()
    {
        return 'SELECT name FROM sysobjects WHERE type = \'U\' ORDER BY name';
    }

    /**
     */
    protected function _limit($query, &$sql, &$bindParams)
    {
        if ($query->limit) {
            $orderby = stristr($sql, 'ORDER BY');
            if ($orderby !== false) {
                $sort = (stripos($orderby, 'DESC') !== false) ? 'DESC' : 'ASC';
                $order = str_ireplace('ORDER BY', '', $orderby);
                $order = trim(preg_replace('/ASC|DESC/i', '', $order));
            }

            $sql = preg_replace('/^SELECT /i', 'SELECT TOP ' . ($query->limit + $query->limitOffset) . ' ', $sql);

            $sql = 'SELECT * FROM (SELECT TOP ' . $query->limit . ' * FROM (' . $sql . ') AS inner_tbl';
            if ($orderby !== false) {
                $sql .= ' ORDER BY ' . $order . ' ';
                $sql .= (stripos($sort, 'ASC') !== false) ? 'DESC' : 'ASC';
            }
            $sql .= ') AS outer_tbl';
            if ($orderby !== false) {
                $sql .= ' ORDER BY ' . $order . ' ' . $sort;
            }
        }
    }

    /**
     * Get a description of the database table that $model is going to
     * reflect.
     */
    public function loadModel($model)
    {
        $tblinfo = $this->select('EXEC sp_columns @table_name = ' . $this->dml->quoteColumnName($model->table));
        while ($col = $tblinfo->fetch()) {
            if (strpos($col['type_name'], ' ') !== false) {
                list($type, $identity) = explode(' ', $col['type_name']);
            } else {
                $type = $col['type_name'];
                $identity = '';
            }

            $model->addField($col['column_name'], array('type' => $type,
                                                        'null' => !(bool)$col['is_nullable'] == 'NO',
                                                        'default' => $col['column_def']));
            if (strtolower($identity) == 'identity') {
                $model->key = $col['column_name'];
            }
        }
    }

    /**
     */
    protected function _lastInsertId($sequence)
    {
        return $this->selectOne('SELECT @@IDENTITY');
    }

}