<?php

namespace Rhymix\Framework;

/**
 * The language class.
 */
class Lang
{
	/**
	 * Instances are stored here.
	 */
	protected static $_instances = array();
	
	/**
	 * Configuration.
	 */
	protected $_language;
	protected $_loaded_directories = array();
	protected $_loaded_plugins = array();
	protected $_search_priority = array();
	
	/**
	 * This method returns the cached instance of a language.
	 * 
	 * @param string $language
	 * @return object
	 */
	public static function getInstance($language)
	{
		if ($language === 'jp')
		{
			$language = 'ja';
		}
		if (!isset(self::$_instances[$language]))
		{
			self::$_instances[$language] = new self($language);
		}
		return self::$_instances[$language];
	}
	
	/**
	 * The constructor should not be called from outside.
	 * 
	 * @param string $language
	 */
	protected function __construct($language)
	{
		$this->_language = preg_replace('/[^a-z0-9_-]/i', '', $language);
		$this->_loaded_plugins['_custom_'] = new \stdClass();
	}
	
	/**
	 * Load translations from a plugin (module, addon).
	 * 
	 * @param string $name
	 * @return bool
	 */
	public function loadPlugin($name)
	{
		if (isset($this->_loaded_plugins[$name]))
		{
			return true;
		}
		
		if ($name === 'common')
		{
			$this->loadDirectory(RX_BASEDIR . 'common/lang', 'common');
		}
		elseif (file_exists(RX_BASEDIR . "plugins/$name/lang"))
		{
			$this->loadDirectory(RX_BASEDIR . "plugins/$name/lang", $name);
		}
		elseif (file_exists(RX_BASEDIR . "modules/$name/lang"))
		{
			$this->loadDirectory(RX_BASEDIR . "modules/$name/lang", $name);
		}
		elseif (file_exists(RX_BASEDIR . "addons/$name/lang"))
		{
			$this->loadDirectory(RX_BASEDIR . "addons/$name/lang", $name);
		}
	}
	
	/**
	 * Load translations from a directory.
	 * 
	 * @param string $dir
	 * @return bool
	 */
	public function loadDirectory($dir, $plugin_name = null)
	{
		// Do not load the same directory twice.
		$dir = rtrim($dir, '/');
		$plugin_name = $plugin_name ?: $dir;
		if (isset($this->_loaded_directories[$dir]) || isset($this->_loaded_plugins[$plugin_name]))
		{
			return true;
		}
		
		// Look for language files.
		if (file_exists($dir . '/' . $this->_language . '.php'))
		{
			$filename = $dir . '/' . $this->_language . '.php';
		}
		elseif (file_exists($dir . '/' . ($this->_language === 'ja' ? 'jp' : $this->_language) . '.lang.php'))
		{
			$filename = $dir . '/' . ($this->_language === 'ja' ? 'jp' : $this->_language) . '.lang.php';
		}
		elseif (($hyphen = strpos($this->_language, '-')) !== false)
		{
			if (file_exists($dir . '/' . substr($this->_language, 0, $hyphen) . '.php'))
			{
				$filename = $dir . '/' . substr($this->_language, 0, $hyphen) . '.php';
			}
			elseif (file_exists($dir . '/' . substr($this->_language, 0, $hyphen) . '.lang.php'))
			{
				$filename = $dir . '/' . substr($this->_language, 0, $hyphen) . '.lang.php';
			}
		}
		elseif (file_exists("$dir/lang.xml"))
		{
			$filename = self::compileXMLtoPHP("$dir/lang.xml", $this->_language === 'ja' ? 'jp' : $this->_language);
		}
		
		// Load the language file.
		if ($filename)
		{
			$lang = new \stdClass;
			include $filename;
			$this->_loaded_directories[$dir] = true;
			$this->_loaded_plugins[$plugin_name] = $lang;
			array_unshift($this->_search_priority, $plugin_name);
			return true;
		}
		else
		{
			$this->_loaded_directories[$dir] = true;
			$this->_loaded_plugins[$plugin_name] = new \stdClass;
			return false;
		}
	}
	
	/**
	 * Convert a directory of old language files to the RhymiX format.
	 * 
	 * @param string $dir
	 * @param array $xml_langs When converting XML to PHP, only convert these languages. (Optional)
	 * @return void
	 */
	public static function convertDirectory($dir, $xml_langs = array())
	{
		if (file_exists("$dir/lang.xml"))
		{
			$langs = count($xml_langs) ? $xml_langs : array_keys(self::getSupportedList());
			foreach ($langs as $lang)
			{
				self::compileXMLtoPHP("$dir/lang.xml", $lang === 'ja' ? 'jp' : $lang, "$dir/$lang.php");
			}
		}
		else
		{
			$files = glob($dir . '/*.lang.php');
			foreach ($files as $filename)
			{
				$new_filename = preg_replace('/\.lang\.php$/', '.php', str_replace('jp.lang', 'ja.lang', $filename));
				\FileHandler::rename($filename, $new_filename);
			}
		}
	}
	
	/**
	 * Compile XE-compatible XML lang files into PHP.
	 * 
	 * @param string $filename
	 * @param string $language
	 * @return string|false
	 */
	public static function compileXMLtoPHP($filename, $language, $output_filename = null)
	{
		// Check if the cache file already exists.
		if ($output_filename === null)
		{
			$output_filename = RX_BASEDIR . 'files/cache/lang/' . md5($filename) . '.' . $language . '.php';
			if (file_exists($output_filename) && filemtime($output_filename) > filemtime($filename))
			{
				return $output_filename;
			}
		}
		
		// Load the XML lang file.
		$xml = @simplexml_load_file($filename);
		if ($xml === false)
		{
			\FileHandler::writeFile($output_filename, '');
			return false;
		}
		
		// Convert XML to a PHP array.
		$lang = array();
		foreach ($xml->item as $item)
		{
			$name = strval($item['name']);
			if (count($item->item))
			{
				$lang[$name] = array();
				foreach ($item->item as $subitem)
				{
					$subname = strval($subitem['name']);
					foreach ($subitem->value as $value)
					{
						$attribs = $value->attributes('xml', true);
						if (strval($attribs['lang']) === $language)
						{
							$lang[$name][$subname] = strval($value);
							break;
						}
					}
				}
			}
			else
			{
				foreach ($item->value as $value)
				{
					$attribs = $value->attributes('xml', true);
					if (strval($attribs['lang']) === $language)
					{
						$lang[$name] = strval($value);
						break;
					}
				}
			}
		}
		unset($xml);
		
		// Save the array as a cache file.
		$buff = "<?php\n";
		foreach ($lang as $key => $value)
		{
			if (is_array($value))
			{
				foreach ($value as $subkey => $subvalue)
				{
					$buff .= '$lang->' . $key . "['" . $subkey . "']" . ' = ' . var_export($subvalue, true) . ";\n";
				}
			}
			else
			{
				$buff .= '$lang->' . $key . ' = ' . var_export($value, true) . ";\n";
			}
		}
		\FileHandler::writeFile($output_filename, $buff);
		return $output_filename;
	}
	
	/**
	 * Get the list of supported languages.
	 * 
	 * @return array
	 */
	public static function getSupportedList()
	{
		return (include RX_BASEDIR . 'common/defaults/lang.php');
	}
	
	/**
	 * Generic getter.
	 * 
	 * @param string $key
	 * @return string
	 */
	public function get($key)
	{
		$args = func_get_args();
		array_shift($args);
		return $this->__call($key, $args);
	}
	
	/**
	 * Magic method for translations without arguments.
	 * 
	 * @param string $key
	 * @return string
	 */
	public function __get($key)
	{
		// Separate the plugin name from the key.
		if (($keys = explode('.', $key, 2)) && count($keys) === 2)
		{
			list($plugin_name, $key) = $keys;
			if (!isset($this->_loaded_plugins[$plugin_name]))
			{
				$this->loadPlugin($plugin_name);
			}
			if (isset($this->_loaded_plugins[$plugin_name]->{$key}))
			{
				return $this->_loaded_plugins[$plugin_name]->{$key};
			}
			else
			{
				return $key;
			}
		}
		
		// Search custom translations first.
		if (isset($this->_loaded_plugins['_custom_']->{$key}))
		{
			return $this->_loaded_plugins['_custom_']->{$key};
		}
		
		// Search other plugins.
		foreach ($this->_search_priority as $plugin_name)
		{
			if (isset($this->_loaded_plugins[$plugin_name]->{$key}))
			{
				return $this->_loaded_plugins[$plugin_name]->{$key};
			}
		}
		
		// If no translation is found, return the key.
		return $key;
	}
	
	/**
	 * Magic method for setting a new custom translation.
	 * 
	 * @param string $key
	 * @param string $value
	 * @return void
	 */
	public function __set($key, $value)
	{
		$this->_loaded_plugins['_custom_']->{$key} = $value;
	}
	
	/**
	 * Magic method for checking whether a translation exists.
	 * 
	 * @param string $key
	 * @return bool
	 */
	public function __isset($key)
	{
		foreach ($this->_loaded_plugins as $plugin_name => $translations)
		{
			if (isset($translations->{$key}))
			{
				return true;
			}
		}
		return false;
	}
	
	/**
	 * Magic method for unsetting a translation.
	 * 
	 * @param string $key
	 * @return void
	 */
	public function __unset($key)
	{
		foreach ($this->_loaded_plugins as $plugin_name => $translations)
		{
			if (isset($translations->{$key}))
			{
				unset($translations->{$key});
			}
		}
	}
	
	/**
	 * Magic method for translations with arguments.
	 * 
	 * @param string $key
	 * @param mixed $args
	 * @return string|null
	 */
	public function __call($key, $args = array())
	{
		// Remove a colon from the beginning of the string.
		if ($key !== '' && $key[0] === ':') $key = substr($key, 1);
		
		// Find the translation.
		$translation = $this->__get($key);
		
		// If there are no arguments, return the translation.
		if (!count($args)) return $translation;
		
		// If there are arguments, interpolate them into the translation and return the result.
		return vsprintf($translation, $args);
	}
}