<?php
/*
*	Project: Nebula Templating Engine
*	By: Mansoor Sayed
*
*
*/
if (!defined('NEBULA_DIR'))
	define('NEBULA_DIR', dirname(__FILE__) . DIRECTORY_SEPARATOR);
if(!defined('PHP'))
	define('PHP', ".php");

class Nebula
{
	var $LEFT_DELIMITER = '{-';		//Opening delimiter
	var $RIGHT_DELIMITER = '-}';	//Opening delimiter
	var $ERROR_REPORT = true;
	var $CACHE = true;  //enable/disable caching
	var $CACHE_DIR = 'Nebula_cache/';// relitive to the php file calling this class's location
	var $PLUGIN_DIR = 'Nebula_plugin/';
	var $TEMPLATE_DIR = 'template/';
	var $PLUGIN_SYNTX = 'plugin.';//Nebula_plugin_name()
	var $PLUGIN_FUNC_STNX = 'Nebula_plugin_'; //sintax for the main function of the plugin
	var $CACHE_FILE_SNTX = 'Nebula_cache.';//Nebula_cache_pagename()

	/*  END OF CONFIG */

	var $CONTLIST = array();
	var $PLUGINS = array();
	var $CONTROLS = array();
	var $CURRPAGE = ''; // for the use of any plugin
	protected static $erroflag = false;
	protected static $pagerro = array();
	var $CACHEINCLUDE = array();

	function start(){
		if(count($this->CONTLIST) == 0) //Checking to see if there is any content.
			$this->_reperro("Error! There is no content to display!");
		$curr_file = $this->CACHE_DIR .$this->CACHE_FILE_SNTX .$this->CURRPAGE .PHP;
		if($this->CACHE === true && file_exists($curr_file) == true)
			include_once($curr_file);
		else{
			$this->_load_plugins();
			$content = $this->_replace($this->_merge(array_reverse($this->CONTLIST)));
			if ($this->ERROR_REPORT == true)
				foreach(Nebula::$pagerro as $erro)
					$content = $erro . $content;
			$fh = fopen($curr_file, 'w');
			fwrite($fh, $content);
			fclose($fh);
			include_once($curr_file);
			if($this->CACHE === false)
				unlink($curr_file);
		}
	}
	function display($content){
	// will not import a file!!
		$this->CONTLIST[] = $content;
	}
	function display_file($file){// import a file as page content
		if (file_exists($file))
		{
			$this->CONTLIST[] = file_get_contents($file);
		}
		else
			$this->_reperro("Error! The file '" .$file ."' was not found!");
	}
	function _merge($parts){
		$content = '';
		foreach ($parts as $peep)
			$content .= $peep;
		return $content;
	}
	function _load_plugins(){// also, as of now, prepares the variable array list
		if ($handle = opendir($this->PLUGIN_DIR)){
			while (false !== ($file = readdir($handle))){
				if(false !== strstr($file, $this->PLUGIN_SYNTX)){
					$prt = explode('.', $file);
					$this->PLUGINS[$prt[1]] = $file;
				}
			}
			closedir($handle);
		}
	}
	function set_controls($controls){
		$this->CONTROLS[] = $controls;
	}
	function cache($pram = true){
		$this->CACHE = $pram;
	}
	function set_currpage($iden){
		$this->CURRPAGE = $iden;
	}
	function clearCache(){
		if ($handle = opendir($this->CACHE_DIR)){
			while (false !== ($file = readdir($handle))){
				if(false !== strstr($file, $this->CACHE_FILE_SNTX)){
					if(!unlink($this->CACHE_DIR .$file))
						$this->_reperro("Error! Cannot delete cache files \"" .$this->CACHE_DIR .$file ."\"<br/>");
				}
			}
			closedir($handle);
			}
		else
			$this->_reperro("Error! Can't open Plugin directory! \"" .$this->CACHE_DIR ."\" Do you have permission? Does it exist?");
	}
	function clearPageCache($page){
		unlink($this->CACHE_DIR .$this->CACHE_FILE_SNTX .$page .PHP);
	}
	function _reperro($erro){
		Nebula::$erroflag = true;
		Nebula::$pagerro[] = $erro . "<br/>";
	}
	function _replace($content)	{// this will take an array of "list" of conditions (boolean) to be tested in the template
		$controls = array();
		$results = array();
		$subpat = "\s*IF\s*([A-Za-z0-9_]+)\s*(\>|\<|\=)\s*(\d|'true'|'false'|[A-Za-z0-9_]+)\s*DO\s*'(.*?)'\s*ELSE\s*'(.*?)'\s*";
		$pattern = '`' .$this->LEFT_DELIMITER ."\s*" .$subpat ."\s*" .$this->RIGHT_DELIMITER .'`i';
		$count = preg_match_all($pattern, $content, $results);
		foreach ($this->PLUGINS as $iden => $fileName){
			$pattern2 = '`' .$this->LEFT_DELIMITER .'\s*' .$iden .'\s*' .$this->RIGHT_DELIMITER .'`i';
			$replace2 = "' . " .$this->PLUGIN_SYNTX .$iden ."() . '";
			for ($i = 0; $i < $count; $i++){
				$results[4][$i] = preg_replace($pattern2, $replace2, $results[4][$i]);
				$results[5][$i] = preg_replace($pattern2, $replace2, $results[5][$i]);
			}
		}
		for ($i = 0; $i<$count; $i++){ // Making sure that there are no php syntax errors at runtime
			switch ($results[2][$i])
			{
			case '<':
				$op = '<';
				break;
			case '>':
				$op = '>';
				break;
			case '=':
				$op = '==';
				break;
				default:$op = '==';// for idk erro avoidence
				$this->_reperro("Invalid Operator!");
				break;
			}
			if (!isset($this->CONTROLS[0][$results[1][$i]]))
				continue;
			$content = str_replace($results[0][$i], '<?php
									if($' .$results[1][$i] .$op .$results[3][$i] .')
									{
									echo \'' .$results[4][$i] .'\';' .'}
									else
									{
									echo \'' .$results[5][$i] .'\';'.'
									}?>', $content);	// Creating the test statement for compiling
		}
		$fakeray = array();
		$fakecounter = 0;
		$ifUsedCount = 0;
		$jumble = $this->LEFT_DELIMITER .'Place_Holder.' .rand() .$this->RIGHT_DELIMITER;
		$pattarn = '`' .$this->LEFT_DELIMITER ."\s*([A-Za-z0-9_]+)\s*" .$this->RIGHT_DELIMITER .'`i';
		$fake_pat = '`' .$this->LEFT_DELIMITER ."(.*)'(.*?)\{-\s*([A-Za-z0-9_]+)\s*-\}(.*?)'(.*)" .$this->RIGHT_DELIMITER .'`i';
		// For returning statements inside the two delimeters that do not make sense without changing it
		preg_match_all($fake_pat, $content, $fakeray);
		$content = preg_replace($fake_pat, $jumble, $content, -1, $fakecounter);
		$includeprt = '<?php ';
		foreach ($this->PLUGINS as $iden => $arrayVar){
			$bob = explode('.', $arrayVar);
			$pattern = '`' .$this->LEFT_DELIMITER .$bob[1] .$this->RIGHT_DELIMITER .'`i';
			$replace = '<?php echo ' .$this->PLUGIN_FUNC_STNX .$iden .'(); ?>';
			$content = preg_replace($pattern, $replace, $content,-1,$ifUsedCount);
			if($ifUsedCount !=0) //this is used to include only the plugins that are used. for optomization...
				$includeprt .= 'include_once(\'' .$this->PLUGIN_DIR .$arrayVar .'\'); ';
		}
		$includeprt .= ' ?>';
		for ($i = 0; $i < $fakecounter; $i++)
			$content = preg_replace('`' .$jumble .'`', $fakeray[0][$i], $content);
		return $includeprt .$content;
	}
}

?>