<?php
/**
 * Logging.
 *
 * Log messages to text files.
 *
 * PHP 5
 *
 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
 * Copyright 2005-2010, Cake Software Foundation, Inc. (http://cakefoundation.org)
 *
 * Licensed under The MIT License
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright 2005-2010, Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link          http://cakephp.org CakePHP(tm) Project
 * @package       cake
 * @subpackage    cake.cake.libs
 * @since         CakePHP(tm) v 0.2.9
 * @license       MIT License (http://www.opensource.org/licenses/mit-license.php)
 */
/**
 * Set up error level constants to be used within the framework if they are not defined within the
 * system.
 *
 */
	if (!defined('LOG_WARNING')) {
		define('LOG_WARNING', 3);
	}
	if (!defined('LOG_NOTICE')) {
		define('LOG_NOTICE', 4);
	}
	if (!defined('LOG_DEBUG')) {
		define('LOG_DEBUG', 5);
	}
	if (!defined('LOG_INFO')) {
		define('LOG_INFO', 6);
	}

/**
 * CakeLogStreamInterface is the interface that should be implemented
 * by all classes that are going to be used as Log streams.
 *
 * @package cake.libs
 */
interface CakeLogInterface {
/**
 * Write method to handle writes being made to the Logger
 *
 * @param string $type 
 * @param string $message 
 * @return void
 * @author Mark Story
 */
	public function write($type, $message);
}

/**
 * Logs messages to configured Log adapters.  One or more adapters can be configured
 * using CakeLogs's methods.  If you don't configure any adapters, and write to the logs
 * a default FileLog will be autoconfigured for you.
 *
 * @package       cake
 * @subpackage    cake.cake.libs
 */
class CakeLog {

/**
 * An array of connected streams.
 * Each stream represents a callable that will be called when write() is called.
 *
 * @var array
 */
	protected static $_streams = array();

/**
 * Configure and add a new logging stream to CakeLog
 * You can use add loggers from app/libs use app.loggername, or any plugin/libs using plugin.loggername.
 *
 * ### Usage:
 *
 * {{{
 * CakeLog::config('second_file', array(
 * 		'engine' => 'FileLog',
 * 		'path' => '/var/logs/my_app/'
 * ));
 * }}}
 *
 * Will configure a FileLog instance to use the specified path.  All options that are not `engine`
 * are passed onto the logging adapter, and handled there.  Any class can be configured as a logging
 * adapter as long as it implements a `write` method with the following signature.
 *
 * `write($type, $message)`
 *
 * For an explaination of these parameters, see CakeLog::write()
 *
 * @param string $key The keyname for this logger, used to remove the logger later.
 * @param array $config Array of configuration information for the logger
 * @return boolean success of configuration.
 * @throws Exception
 */
	public static function config($key, $config) {
		if (empty($config['engine'])) {
			throw new Exception(__('Missing logger classname'));
		}
		$loggerName = $config['engine'];
		unset($config['engine']);
		$className = self::_getLogger($loggerName);
		$logger = new $className($config);
		if (!$logger instanceof CakeLogInterface) {
			throw new Exception(sprintf(
				__('logger class %s does not implement a write method.'), $loggerName
			));
		}
		self::$_streams[$key] = $logger;
		return true;
	}

/**
 * Attempts to import a logger class from the various paths it could be on.
 * Checks that the logger class implements a write method as well.
 *
 * @param string $loggerName the plugin.className of the logger class you want to build.
 * @return mixed boolean false on any failures, string of classname to use if search was successful.
 */
	protected static function _getLogger($loggerName) {
		list($plugin, $loggerName) = pluginSplit($loggerName);

		if ($plugin) {
			App::import('Lib', $plugin . '.log/' . $loggerName);
		} else {
			if (!App::import('Lib', 'log/' . $loggerName)) {
				App::import('Core', 'log/' . $loggerName);
			}
		}
		if (!class_exists($loggerName)) {
			throw new Exception(sprintf(__('Could not load class %s'), $loggerName));
		}
		return $loggerName;
	}

/**
 * Returns the keynames of the currently active streams
 *
 * @return array Array of configured log streams.
 */
	public static function configured() {
		return array_keys(self::$_streams);
	}

/**
 * Removes a stream from the active streams.  Once a stream has been removed
 * it will no longer have messages sent to it.
 *
 * @param string $keyname Key name of a configured stream to remove.
 * @return void
 */
	public static function drop($streamName) {
		unset(self::$_streams[$streamName]);
	}

/**
 * Configures the automatic/default stream a FileLog.
 *
 * @return void
 */
	protected static function _autoConfig() {
		if (!class_exists('FileLog')) {
			App::import('Core', 'log/FileLog');
		}
		self::$_streams['default'] = new FileLog(array('path' => LOGS));
	}

/**
 * Writes the given message and type to all of the configured log adapters.
 * Configured adapters are passed both the $type and $message variables. $type
 * is one of the following strings/values.
 *
 * ### Types:
 *
 * - `LOG_WARNING` => 'warning',
 * - `LOG_NOTICE` => 'notice',
 * - `LOG_INFO` => 'info',
 * - `LOG_DEBUG` => 'debug',
 * - `LOG_ERR` => 'error',
 * - `LOG_ERROR` => 'error'
 *
 * ### Usage:
 *
 * Write a message to the 'warning' log:
 * 
 * `CakeLog::write('warning', 'Stuff is broken here');`
 *
 * @param string $type Type of message being written
 * @param string $message Message content to log
 * @return boolean Success
 */
	public static function write($type, $message) {
		if (!defined('LOG_ERROR')) {
			define('LOG_ERROR', 2);
		}
		if (!defined('LOG_ERR')) {
			define('LOG_ERR', LOG_ERROR);
		}
		$levels = array(
			LOG_WARNING => 'warning',
			LOG_NOTICE => 'notice',
			LOG_INFO => 'info',
			LOG_DEBUG => 'debug',
			LOG_ERR => 'error',
			LOG_ERROR => 'error'
		);

		if (is_int($type) && isset($levels[$type])) {
			$type = $levels[$type];
		}
		if (empty(self::$_streams)) {
			self::_autoConfig();
		}
		foreach (self::$_streams as $key => $logger) {
			$logger->write($type, $message);
		}
		return true;
	}
}