<?php

/*

 * Copyright 2010-2013 by MODX, LLC.

 *

 * This file is part of xPDO.

 *

 * xPDO 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.

 *

 * xPDO 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

 * xPDO; if not, write to the Free Software Foundation, Inc., 59 Temple Place,

 * Suite 330, Boston, MA 02111-1307 USA

 */



/**

 * The MySQL implementation of xPDOQuery.

 *

 * @package xpdo

 * @subpackage om.mysql

 */



/** Include the base {@see xPDOQuery} class */

include_once (dirname(dirname(__FILE__)) . '/xpdoquery.class.php');



/**

 * An implementation of xPDOQuery for the MySQL database engine.

 *

 * @package xpdo

 * @subpackage om.mysql

 */

class xPDOQuery_mysql extends xPDOQuery {

    public function __construct(& $xpdo, $class, $criteria= null) {

        parent :: __construct($xpdo, $class, $criteria);

        $this->query['priority']= '';

    }



    public function construct() {

        $constructed= false;

        $this->bindings= array ();

        $command= strtoupper($this->query['command']);

        $sql= $this->query['command'] . ' ';

        if ($command == 'SELECT') $sql.= $this->query['distinct'] ? $this->query['distinct'] . ' ' : '';

        if ($command == 'SELECT') $sql.= $this->query['priority'] ? $this->query['priority'] . ' ' : '';

        if ($command == 'SELECT') {

            $columns= array ();

            if (empty ($this->query['columns'])) {

                $this->select('*');

            }

            foreach ($this->query['columns'] as $alias => $column) {

                $ignorealias = is_int($alias);

                $escape = !preg_match('/\bAS\b/i', $column) && !preg_match('/\./', $column) && !preg_match('/\(/', $column);

                if ($escape) {

                    $column= $this->xpdo->escape(trim($column));

                } else {

                    $column= trim($column);

                }

                if (!$ignorealias) {

                    $alias = $escape ? $this->xpdo->escape($alias) : $alias;

                    $columns[]= "{$column} AS {$alias}";

                } else {

                    $columns[]= "{$column}";

                }

            }

            $sql.= implode(', ', $columns);

            $sql.= ' ';

        }

        if ($command != 'UPDATE') {

            $sql.= 'FROM ';

        }

        $tables= array ();

        foreach ($this->query['from']['tables'] as $table) {

            if ($command != 'SELECT') {

                $tables[]= $table['table'];

            } else {

                $tables[]= $table['table'] . ' AS ' . $this->xpdo->escape($table['alias']);

            }

        }

        $sql.= $this->query['from']['tables'] ? implode(', ', $tables) . ' ' : '';

        if (!empty ($this->query['from']['joins'])) {

            foreach ($this->query['from']['joins'] as $join) {

                $sql.= $join['type'] . ' ' . $join['table'] . ' ' . $this->xpdo->escape($join['alias']) . ' ';

                if (!empty ($join['conditions'])) {

                    $sql.= 'ON ';

                    $sql.= $this->buildConditionalClause($join['conditions']);

                    $sql.= ' ';

                }

            }

        }

        if ($command == 'UPDATE') {

            if (!empty($this->query['set'])) {

                reset($this->query['set']);

                $clauses = array();

                while (list($setKey, $setVal) = each($this->query['set'])) {

                    $value = $setVal['value'];

                    $type = $setVal['type'];

                    if ($value !== null && in_array($type, array(PDO::PARAM_INT, PDO::PARAM_STR))) {

                        $value = $this->xpdo->quote($value, $type);

                    } elseif ($value === null) {

                        $value = 'NULL';

                    }

                    $clauses[] = $this->xpdo->escape($setKey) . ' = ' . $value;

                }

                if (!empty($clauses)) {

                    $sql.= 'SET ' . implode(', ', $clauses) . ' ';

                }

                unset($clauses);

            }

        }

        if (!empty ($this->query['where'])) {

            if ($where= $this->buildConditionalClause($this->query['where'])) {

                $sql.= 'WHERE ' . $where . ' ';

            }

        }

        if ($command == 'SELECT' && !empty ($this->query['groupby'])) {

            $groupby= reset($this->query['groupby']);

            $sql.= 'GROUP BY ';

            $sql.= $groupby['column'];

            if ($groupby['direction']) $sql.= ' ' . $groupby['direction'];

            while ($groupby= next($this->query['groupby'])) {

                $sql.= ', ';

                $sql.= $groupby['column'];

                if ($groupby['direction']) $sql.= ' ' . $groupby['direction'];

            }

            $sql.= ' ';

        }

        if (!empty ($this->query['having'])) {

            $sql.= 'HAVING ';

            $sql.= $this->buildConditionalClause($this->query['having']);

            $sql.= ' ';

        }

        if ($command == 'SELECT' && !empty ($this->query['sortby'])) {

            $sortby= reset($this->query['sortby']);

            $sql.= 'ORDER BY ';

            $sql.= $sortby['column'];

            if ($sortby['direction']) $sql.= ' ' . $sortby['direction'];

            while ($sortby= next($this->query['sortby'])) {

                $sql.= ', ';

                $sql.= $sortby['column'];

                if ($sortby['direction']) $sql.= ' ' . $sortby['direction'];

            }

            $sql.= ' ';

        }

        if ($limit= intval($this->query['limit'])) {

            $sql.= 'LIMIT ';

            if ($offset= intval($this->query['offset'])) $sql.= $offset . ', ';

            $sql.= $limit . ' ';

        }

        $this->sql= $sql;

        return (!empty ($this->sql));

    }

}