<?php

/*

 * Enano - an open-source CMS capable of wiki functions, Drupal-like sidebar blocks, and everything in between

 * Copyright (C) 2006-2009 Dan Fuhry

 * Installation package

 * sql_parse.php - SQL query splitter and templater

 *

 * This program is Free Software; you can redistribute 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.

 *

 * This program 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 details.

 */

/**

 * Parses a full file of SQL into individual queries. Also includes substitution (template) functions.

 * @package Enano

 * @subpackage Installer

 * @author Dan Fuhry

 */

class SQL_Parser

{

	/**

 	* The SQL to be parsed.

 	* @var string

 	* @access private

 	*/

	private $sql_string;

	/**

 	* Parsed SQL array

 	* @var array

 	* @access private

 	*/

	private $sql_array;

	/**

 	* Template variables.

 	* @var array

 	* @access private

 	*/

	private $tpl_strings;

	/**

 	* Constructor.

 	* @param string If this contains newlines, it will be treated as the target SQL. If not, will be treated as a filename.

 	* @param string If true, force as raw SQL, i.e. don't treat as a filename no matter what

 	*/

	public function __construct($sql, $force_file = false)

	{

		if ( strpos($sql, "\n") || $force_file )

		{

			$this->sql_string = $sql;

		}

		else

		{

			if ( file_exists($sql) )

			{

				$this->sql_string = @file_get_contents($sql);

				if ( empty($this->sql_string) )

				{

					throw new Exception('SQL file is blank or permissions are bad');

				}

			}

			else

			{

				throw new Exception('SQL file doesn\'t exist');

			}

		}

		$this->sql_array = false;

		$this->tpl_strings = array();

		// convert \r\n in the schema to \n, in case some FTP client or zip utility ran unix2dos for us

		// thanks to InvisGhost for reporting this error

		$this->sql_string = str_replace("\r\n", "\n", $this->sql_string);

	}

	/**

 	* Sets template variables.

 	* @param array Associative array of template variables to assign

 	*/

	public function assign_vars($vars)

	{

		if ( !is_array($vars) )

			return false;

		$this->tpl_strings = array_merge($this->tpl_strings, $vars);

	}

	/**

 	* Internal function to parse the SQL.

 	* @access private

 	*/

	private function parse_sql()

	{

		$this->sql_array = $this->sql_string;

		foreach ( $this->tpl_strings as $key => $value )

		{

			$this->sql_array = str_replace("{{{$key}}}", $value, $this->sql_array);

		}

		// Strip out comments

		$this->sql_array = explode("\n", $this->sql_array);

		foreach ( $this->sql_array as $i => $sql )

		{

			$query =& $this->sql_array[$i];

			$t = trim($query);

			if ( preg_match('/^(\#|--)/i', $t) )

			{

				unset($this->sql_array[$i]);

				unset($query);

			}

		}

		unset($query);

		$this->sql_array = array_values($this->sql_array);

		$this->sql_array = implode("\n", $this->sql_array);

		$this->sql_array = explode(";\n", trim($this->sql_array));

		foreach ( $this->sql_array as $i => $sql )

		{

			$query =& $this->sql_array[$i];

			$query = trim($query);

			if ( substr($query, ( strlen($query) - 1 ), 1 ) != ';' )

			{

				$query .= ';';

			}

		}

		unset($query);

	}

	/**

 	* Returns the parsed array of SQL queries.

 	* @param bool Optional. Defaults to false. If true, a parse is performed even if it already happened.

 	* @return array

 	*/

	public function parse($force_reparse = false)

	{

		if ( !$this->sql_array || $force_reparse )

			$this->parse_sql();

		return $this->sql_array;

	}

}

?>