<?php 

/**
 * Unit testing helpers
 */
class Kohana_Unittest_Helpers {
	/**
	 * Static variable used to work out whether we have an internet 
	 * connection 
	 * @see has_internet
	 * @var boolean
	 */
	static protected $_has_internet = NULL;

	/**
	 * Check for internet connectivity
	 *
	 * @return boolean Whether an internet connection is available
	 */
	public static function has_internet()
	{
		if ( ! isset(self::$_has_internet))
		{
			// The @ operator is used here to avoid DNS errors when there is no connection.
			$sock = @fsockopen("www.google.com", 80, $errno, $errstr, 1);

			self::$_has_internet = (bool) $sock ? TRUE : FALSE;
		}

		return self::$_has_internet;
	}

	/**
	 * Helper function which replaces the "/" to OS-specific delimiter
	 * 
	 * @param string $path
	 * @return string
	 */
	static public function dir_separator($path)
	{
		return str_replace('/', DIRECTORY_SEPARATOR, $path);
	}

	/**
	 * Removes all cache files from the kohana cache dir 
	 *
	 * @return void
	 */
	static public function clean_cache_dir()
	{
		$cache_dir = opendir(Kohana::$cache_dir);

		while ($dir = readdir($cache_dir))
		{
			// Cache files are split into directories based on first two characters of hash
			if ($dir[0] !== '.' AND strlen($dir) === 2)
			{
				$dir = self::dir_separator(Kohana::$cache_dir.'/'.$dir.'/');
	
				$cache = opendir($dir);

				while ($file = readdir($cache))
				{
					if ($file[0] !== '.')
					{
						unlink($dir.$file);
					}
				}

				closedir($cache);

				rmdir($dir);
			}
		}

		closedir($cache_dir);
	}

	/**
	 * Backup of the environment variables
	 * @see set_environment
	 * @var array
	 */
	protected $_environment_backup = array();

	/**
	 * Allows easy setting & backing up of enviroment config
	 *
	 * Option types are checked in the following order:
	 *
	 * * Server Var
	 * * Static Variable
	 * * Config option
	 *
	 * @param array $environment List of environment to set
	 */
	public function set_environment(array $environment)
	{
		if ( ! count($environment))
			return FALSE;

		foreach ($environment as $option => $value)
		{
			$backup_needed = ! array_key_exists($option, $this->_environment_backup);

			// Handle changing superglobals
			if (in_array($option, array('_GET', '_POST', '_SERVER', '_FILES')))
			{
				// For some reason we need to do this in order to change the superglobals
				global $$option;

				if ($backup_needed)
				{
					$this->_environment_backup[$option] = $$option;
				}

				// PHPUnit makes a backup of superglobals automatically
				$$option = $value;
			}
			// If this is a static property i.e. Html::$windowed_urls
			elseif (strpos($option, '::$') !== FALSE)
			{
				list($class, $var) = explode('::$', $option, 2);

				$class = new ReflectionClass($class);

				if ($backup_needed)
				{
					$this->_environment_backup[$option] = $class->getStaticPropertyValue($var);
				}

				$class->setStaticPropertyValue($var, $value);
			}
			// If this is an environment variable
			elseif (preg_match('/^[A-Z_-]+$/D', $option) OR isset($_SERVER[$option]))
			{
				if ($backup_needed)
				{
					$this->_environment_backup[$option] = isset($_SERVER[$option]) ? $_SERVER[$option] : '';
				}
				
				$_SERVER[$option] = $value;
			}
			// Else we assume this is a config option
			else
			{
				if ($backup_needed)
				{
					$this->_environment_backup[$option] = Kohana::config($option);
				}

				list($group, $var) = explode('.', $option, 2);

				Kohana::config($group)->set($var, $value);
			}
		}
	}

	/**
	 * Restores the environment to the original state
	 *
	 * @chainable
	 * @return Kohana_Unittest_Helpers $this 
	 */
	public function restore_environment()
	{
		$this->set_environment($this->_environment_backup);	
	}
}
