<?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;
	}
}

?>