<?php

/**

 * Query parser. Processes queries for SQL access.

 *

 * @package Recipe 1.2

 * @author Sebastian Noll

 * @copyright Copyright (c) 2009, Sebastian Noll

 * @license Proprietary

 * @version $Id: QueryParser.php 46 2011-07-30 14:38:11Z secretchampion $

 */



class Recipe_QueryParser

{

	/**

	 * Last SQL query.

	 *

	 * @var string

	 */

	protected $sql = "";



	/**

	 * Disables auto-sending of a query.

	 *

	 * @var boolean

	 */

	protected $send = true;



	/**

	 * @ignore

	 */

	public function __construct() {}



	/**

	 * Generates an insert sql query.

	 *

	 * @param string $table

	 * @param array $spec

	 * @return \Recipe_Database_Statement_Abstract

	 */

	public function insert($table, array $spec)

	{

		$attributes = array_keys($spec);

		$attributes = $this->setBackQuotes($attributes);

		$values = array_fill(0, count($spec), "?");

		$sql = "INSERT INTO `".PREFIX.$table."` (".implode(",", $attributes).") VALUES (".implode(",", $values).")";

		return $this->send($sql, $spec);

	}



	/**

	 * Generates an insert sql query.

	 *

	 * @param string $table

	 * @param array $spec

	 * @param string $where

	 * @param array $bind

	 * @return Recipe_Database_Statement_Abstract

	 */

	public function update($table, array $spec, $where = null, array $bind = null)

	{

		if($bind !== null)

		{

			$bind = $spec + $bind;

		}

		else

		{

			$bind = $spec;

		}

		foreach($spec as $attribute => &$value)

		{

			if(!($value instanceof Recipe_Database_Expr))

			{

				$value = "?";

			}

			else

			{

				unset($bind[$attribute]);

			}

			$value = "`".$attribute."` = ".$value;

		}

		$sql = "UPDATE `".PREFIX.$table."` SET ".implode(",", $spec);



		if($where !== null)

		{

			$sql .= " WHERE ".$where;

		}



		return $this->send($sql, $bind);

	}



	/**

	 * Sends an SQL query.

	 *

	 * @param string $sql

	 * @param array $bind

	 * @return Recipe_Database_Statement_Abstract

	 */

	protected function send($sql, array $bind = null)

	{

		$statement = null;

		$this->sql = $sql;

		if($this->send)

		{

			try {

				$statement = Core::getDatabase()->query($this->sql, $bind);

			} catch(Recipe_Exception_Sql $e) {

				$e->printError();

			}

		}

		$this->send = true;

		return $statement;

	}



	/**

	 * Generates a select query.

	 *

	 * @param string $table

	 * @param string|array $select

	 * @param string $join

	 * @param string $where

	 * @param string $order

	 * @param string $limit

	 * @param string $groupby

	 * @param string $other

	 * @param array $bind

	 *

	 * @return Recipe_Database_Statement_Abstract

	 */

	public function select($table, $select, $join = "", $where = "", $order = "", $limit = "", $groupby = "", $other = "", array $bind = null)

	{

		if(!is_array($select))

		{

			$select = Arr::trim(explode(",", $select));

		}



		if(!empty($join)) { $join = " ".$join; }

		if(!empty($where)) { $where = " WHERE ".$where; }

		if(!empty($groupby)) { $groupby = " GROUP BY ".$groupby; }

		if(!empty($order)) { $order = " ORDER BY ".$order; }

		if(!empty($limit)) { $limit = " LIMIT ".$limit; }

		$other = (!empty($other)) ? " ".$other : "";

		$select = implode(", ", $select);

		$sql = "SELECT ".$select." FROM ".PREFIX.$table.$join.$where.$groupby.$order.$limit.$other;

		return $this->send($sql, $bind);

	}



	/**

	 * Generates a delete query.

	 *

	 * @param string $table

	 * @param string $where

	 * @param string $order

	 * @param string $limit

	 * @param array $bind

	 * @return Recipe_Database_Statement_Abstract

	 */

	public function delete($table, $where = null, $order = null, $limit = null, array $bind = null)

	{

		$whereclause = "";

		$orderclause = "";

		$limitclause = "";

		if(!is_null($where) && Str::length($where) > 0)

		{

			$whereclause = " WHERE ".$where;

		}

		if(!is_null($order) && Str::length($order) > 0)

		{

			$orderclause = " ORDER BY ".$order;

		}

		if(!is_null($limit) && !empty($limit))

		{

			$limitclause = " LIMIT ".$limit;

		}



		$sql = "DELETE FROM ".PREFIX.$table.$whereclause.$orderclause.$limitclause;



		return $this->send($sql, $bind);

	}



	/**

	 * Empties a table completely.

	 *

	 * @param string $table

	 *

	 * @return Recipe_Database_Statement_Abstract

	 */

	public function truncate($table)

	{

		$table = $this->setBackQuotes(PREFIX.$table);

		return $this->send("TRUNCATE TABLE ".$table);

	}



	/**

	 * Reclaims the unused space of a database file.

	 *

	 * @param mixed $tables

	 *

	 * @return Recipe_Database_Statement_Abstract

	 */

	public function optimize($tables)

	{

		if(is_array($tables))

		{

			$tables = $this->setPrefix($tables);

			$tables = $this->setBackQuotes($tables);

			$table = implode(", ", $tables);

		}

		else

		{

			$table = $this->setBackQuotes(PREFIX.$tables);

		}



		return $this->send("OPTIMIZE TABLE ".$table);

	}



	/**

	 * Removes one or more tables.

	 *

	 * @param mixed $tables

	 *

	 * @return Recipe_Database_Statement_Abstract

	 */

	public function drop($tables)

	{

		if(is_array($tables))

		{

			$tables = $this->setPrefix($tables);

			$tables = $this->setBackQuotes($tables);

			$table = implode(", ", $tables);

		}

		else

		{

			$table = $this->setBackQuotes(PREFIX.$tables);

		}

		return $this->send("DROP TABLE IF EXISTS ".$table);

	}



	/**

	 * Renames a table.

	 *

	 * @param string $table

	 * @param string $newname

	 *

	 * @return Recipe_Database_Statement_Abstract

	 */

	public function rename($table, $newname)

	{

		$table = $this->setBackQuotes(PREFIX.$table);

		$newname = $this->setBackQuotes(PREFIX.$newname);

		return $this->send("RENAME TABLE ".$table." TO ".$newname);

	}



	/**

	 * Returns information about the columns in the given table.

	 *

	 * @param string $table

	 *

	 * @return Recipe_Database_Statement_Abstract

	 */

	public function showFields($table)

	{

		$table = $this->setBackQuotes(PREFIX.$table);

		return $this->send("SHOW COLUMNS FROM ".$table);

	}



	/**

	 * Surrounds an array with simple quotes.

	 *

	 * @param array $data

	 *

	 * @return array

	 */

	protected function setSimpleQuotes($data)

	{

		if(is_array($data))

		{

			foreach($data as &$value)

			{

				if(!($value instanceof Recipe_Database_Expr))

				{

					$value = (is_null($value)) ? "NULL" : "'".$value."'";

				}

			}

			return $data;

		}

		return (is_null($data)) ? "NULL" : "'".$data."'";

	}



	/**

	 * Surrounds an array with back quotes.

	 *

	 * @param array

	 *

	 * @return array

	 */

	protected function setBackQuotes($data)

	{

		if(is_array($data))

		{

			foreach($data as &$value)

			{

				if(Str::substring($value, 0, 1) != "`")

				{

					$value = "`".$value."`";

				}

			}

			return $data;

		}

		if(Str::substring($data, 0, 1) == "`")

		{

			return $data;

		}

		return "`".$data."`";

	}



	/**

	 * Returns the last generated SQL query.

	 *

	 * @return string	Last SQL query

	 */

	public function getLastQuery()

	{

		return $this->sql;

	}



	/**

	 * Sets the prefix to an array of table names.

	 *

	 * @param array

	 *

	 * @return array

	 */

	protected function setPrefix($tables)

	{

		$size = count($tables);

		for($i = 0; $i < $size; $i++)

		{

			$tables[$i] = PREFIX.$tables[$i];

		}

		return $tables;

	}



	/**

	 * Sets whether the next generated query should be executed.

	 *

	 * @param boolean

	 *

	 * @return Recipe_QueryParser

	 */

	public function sendNextQuery($send)

	{

		$this->send = $send;

		return $this;

	}

}

?>