<?php

abstract class Provider extends Entity implements IteratorAggregate {
	
	protected static 
		$type,
		$subType,
		$rootType,
		$parentType,
		$providers = array();
	
	final public static function addProviderDir ( $dir, $cache = null ) {
		
		static::checkDirectories($dir, $cache);
		
		foreach ( scandir($dir) as $name )
			if ( file_exists($dir . '/' . $name . '/provider.php') ) {
				
				if ( $cache && !file_exists($cache . '/' . $name) )
					mkdir($cache . '/' . $name, 0777, 1);
				
				self::set($name, $dir . '/' . $name, $cache ? $cache . '/' . $name : null);
				
			}
		
	}
	
	final public static function set ( $name, $dir, $cache = '' ) {
		
		if ( !empty(self::$providers[$name]) )
			throw new Exception(sprintf(
				'Provider "%1$s" already set !',
				$name
			));
		
		static::checkDirectories($dir, $cache);
		
		self::$providers[$name] = array($dir, $cache);
		
	}
	
	final public static function checkDirectories ( $folder, $cache = null ) {
		
		if ( !( $exists = file_exists($folder) ) || !is_dir($folder) )
			throw new Exception(sprintf(
				$exists ? 
					'Directory "%1$s" doest not exists ! It is a file !' :
					'Directory "%1$s" doest not exists !',
				$folder
			));
		
		if ( $cache && ( !( $exists = file_exists($cache) ) || !is_dir($cache) ) )
			throw new Exception(sprintf(
				$exists ? 
					'Directory "%1$s" doest not exists ! It is a file !' :
					'Directory "%1$s" doest not exists !',
				$cache
			));
		
	}
	
	protected static function getInstance ( $name ) {
		
		//~ echo sprintf(
			//~ '%1$s::%2$s(%3$s)' . "\n",
			//~ get_called_class(),
			//~ __METHOD__,
			//~ $name
		//~ );
		
		if ( empty(self::$providers[$name]) )
			throw new Exception(sprintf(
				'Provider "%1$s" not registered !',
				$name
			));
		
		$data = include(self::$providers[$name][0] . '/provider.php');
		
		$data['name'] = $name;
		$class = $data['type'];
		
		return new $class($data);
		
	}
	
	abstract protected function build ();
	
	protected function __construct ( $data, $parent = null ) {
		
		parent::__construct($data, $parent);
		
		$this->load();
		
	}
	
	public function getIterator () {
		
		return $this->__get('Model');
		
	}
	
	protected function load () {
		
		// if not in cache
		if ( !$this->loadFromCache() ) {
			
			// if no model structure found
			$this->loadFromFiles();
			$this->build();
			
			$this->saveToFiles();
			
			// merge data for faster access and cache
			$this->saveToCache();
			
		}
		
		return $this;
		
	}
	
	private function loadFromFiles () {
		
		$loaded = false;
		$name = $this->getName();
		if ( $dir = self::$providers[$name][0] ) {
			
			foreach ( scandir($dir) as $file )
				if ( preg_match('!^([a-zA-Z0-9_]++)\.([a-zA-Z0-9_]++)\.php$!', $file, $m) ) {
					
					$loaded = true;
					$this->data['children'][$m[1]][$m[2]] = include($dir . '/' . $file);
					
				}
			
		}
		
/*#BEGIN debug#*/
		return false;
/*#END debug#*/
		return $loaded;
		
	}
	
	private function saveToFiles ( ) {
		
		$name = $this->getName();
		if ( $dir = self::$providers[$name][0] ) {
			
			$dir .= '/auto';
			if ( !file_exists($dir) )
				mkdir($dir, 0777, 1);
			
			$provider = $this->data;
			unset($provider['children']);
			phpize($provider, $dir . '/provider.php');
			
			foreach ( $this->data['children'] as $type => $instances )
				foreach ( $instances as $k => $instance )
					phpize($instance, sprintf(
						'%1$s/%2$s.%3$s.php',
						$dir,
						$type,
						$k
					));
			
		}
		
		//~ if ( $dir = self::$providers[$name][1] ) {
			
			//~ if ( !file_exists($dir = dirname($this->cachePath) . '/' . $this->getName()) )
				//~ mkdir($dir, 0770, 1);
			
			//~ foreach ( $props as $f )
				//~ phpize($this->$f, $dir . '/' . $f . '.php');
			
		//~ }
		
		return $this;
		
	}
	
	private function loadFromCache ( ) {
		
		if ( $cache = self::$providers[$name = $this->getName()][1] ) {
			
			$cacheFile = sprintf(
				'%1$s/provider.php',
				$cache
			);
			
/*#BEGIN debug#*/
		//~ // clear the cache if it is.
			if ( file_exists($cacheFile) )
				unlink($cacheFile);
			
/*#END debug#*/
			
			$cached = null;
			if ( file_exists($cacheFile) )
				$cached = include($cacheFile);
			
			// restore the cache
			if ( $cached ) {
				
				$this->data = $cached;
				
				$cached = null;
				
				return true;
				
			}
			
		}
		
		return false;
		
	}
	
	private function saveToCache ( ) {
		
		// Cache the merged model data
		if ( $cache = self::$providers[$name = $this->getName()][1] ) {
			
			$cacheFile = sprintf(
				'%1$s/provider.php',
				$cache
			);
			
			phpize($this->data, $cacheFile);
			
		}
		
		return $this;
		
	}
	
}

?>