/* console.js is part of Aloha Editor project http://aloha-editor.org
 *
 * Aloha Editor is a WYSIWYG HTML5 inline editing library and editor. 
 * Copyright (c) 2010-2012 Gentics Software GmbH, Vienna, Austria.
 * Contributors http://aloha-editor.org/contribution.php 
 * 
 * Aloha Editor is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or any later version.
 *
 * Aloha Editor is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * 
 * As an additional permission to the GNU GPL version 2, you may distribute
 * non-source (e.g., minimized or compacted) forms of the Aloha-Editor
 * source code without the copy of the GNU GPL normally required,
 * provided you include this license notice and a URL through which
 * recipients can access the Corresponding Source.
 */
define([
	'aloha/core',
	'util/class',
	'jquery'
], function (
	Aloha,
	Class,
	jQuery
) {
	"use strict";

	/**
	 * This is the aloha Log
	 * @namespace Aloha
	 * @class Log
	 * @singleton
	 */
	var AlohaConsole = Class.extend({
		/**
		 * Initialize the logging
		 * @hide
		 */
		init: function () {

			// initialize the logging settings (if not present)
			if (typeof Aloha.settings.logLevels === 'undefined' || !Aloha.settings.logLevels) {
				Aloha.settings.logLevels = {
					'error': true,
					'warn': true
				};
			}

			// initialize the logHistory settings (if not present)
			if (typeof Aloha.settings.logHistory === 'undefined' || !Aloha.settings.logHistory) {
				Aloha.settings.logHistory = {};
			}
			// set the default values for the loghistory
			if (!Aloha.settings.logHistory.maxEntries) {
				Aloha.settings.logHistory.maxEntries = 100;
			}
			if (!Aloha.settings.logHistory.highWaterMark) {
				Aloha.settings.logHistory.highWaterMark = 90;
			}
			if (!Aloha.settings.logHistory.levels) {
				Aloha.settings.logHistory.levels = {
					'error': true,
					'warn': true
				};
			}
			this.flushLogHistory();

			Aloha.trigger('aloha-logger-ready');
		},

		/**
		 * Log History as array of Message Objects. Every object has the properties
		 * 'level', 'component' and 'message'
		 * @property
		 * @type Array
		 * @hide
		 */
		logHistory: [],

		/**
		 * Flag, which is set as soon as the highWaterMark for the log history is reached.
		 * This flag is reset on every call of flushLogHistory()
		 * @hide
		 */
		highWaterMarkReached: false,

		/**
		 * Logs a message to the console
		 * @method
		 * @param {String} level Level of the log ('error', 'warn' or 'info', 'debug')
		 * @param {String} component Component that calls the log
		 * @param {String} message log message
		 */
		log: function (level, component, message) {


			// log ('Logging message');
			if (typeof component === 'undefined') {
				message = level;
			}
			if (typeof component !== 'string' && component && component.toString) {
				component = component.toString();
			}

			// log ('warn', 'Warning message');
			if (typeof message === 'undefined') {
				message = component;
				component = undefined;
			}

			if (typeof level === 'undefined' || !level) {
				level = 'log';
			}

			level = level.toLowerCase();

			if (typeof Aloha.settings.logLevels === "undefined") {
				return;
			}

			// now check whether the log level is activated
			if (!Aloha.settings.logLevels[level]) {
				return;
			}

			component = component || "Unkown Aloha Component";

			this.addToLogHistory({
				'level': level,
				'component': component,
				'message': message,
				'date': new Date()
			});

			var console = window.console;

			switch (level) {
			case 'error':
				if (window.console && console.error) {
					// FIXME:
					// Using console.error rather than throwing an error is very
					// problematic because we get not stack.
					// We ought to consider doing the following:
					// throw component + ': ' + message;
					if (!component && !message) {
						console.error("Error occured without message and component");
					} else {
						console.error(component + ': ' + message);
					}
				}
				break;
			case 'warn':
				if (window.console && console.warn) {
					console.warn(component + ': ' + message);
				}
				break;
			case 'info':
				if (window.console && console.info) {
					console.info(component + ': ' + message);
				}
				break;
			case 'debug':
				if (window.console && console.log) {
					console.log(component + ' [' + level + ']: ' + message);
				}
				break;
			default:
				if (window.console && console.log) {
					console.log(component + ' [' + level + ']: ' + message);
				}
				break;
			}
		},

		/**
		 * Log a message of log level 'error'
		 * @method
		 * @param {String} component Component that calls the log
		 * @param {String} message log message
		 */
		error: function (component, message) {
			this.log('error', component, message);
		},

		/**
		 * Log a message of log level 'warn'
		 * @method
		 * @param {String} component Component that calls the log
		 * @param {String} message log message
		 */
		warn: function (component, message) {
			this.log('warn', component, message);
		},

		/**
		 * Log a message of log level 'info'
		 * @method
		 * @param {String} component Component that calls the log
		 * @param {String} message log message
		 */
		info: function (component, message) {
			this.log('info', component, message);
		},

		/**
		 * Log a message of log level 'debug'
		 * @param {String} component Component that calls the log
		 * @param {String} message log message
		 */
		debug: function (component, message) {
			this.log('debug', component, message);
		},

		/**
		 * Methods to mark function as deprecated for developers.
		 * @param {String} component String that calls the log
		 * @param {String} message log message
		 */
		deprecated: function (component, message) {
			this.log('warn', component, message);
			// help the developer to locate the call.
			if (Aloha.settings.logLevels.deprecated) {
				throw new Error(message);
			}
		},

		/**
		 * Check whether the given log level is currently enabled
		 * @param {String} level
		 * @return true when log level is enabled, false if not
		 */
		isLogLevelEnabled: function (level) {
			return Aloha.settings && Aloha.settings.logLevels && Aloha.settings.logLevels[level];
		},

		/**
		 * Check whether error logging is enabled
		 * @return true if error logging is enabled, false if not
		 */
		isErrorEnabled: function () {
			return this.isLogLevelEnabled('error');
		},

		/**
		 * Check whether warn logging is enabled
		 * @return true if warn logging is enabled, false if not
		 */
		isWarnEnabled: function () {
			return this.isLogLevelEnabled('warn');
		},

		/**
		 * Check whether info logging is enabled
		 * @return true if info logging is enabled, false if not
		 */
		isInfoEnabled: function () {
			return this.isLogLevelEnabled('info');
		},

		/**
		 * Check whether debug logging is enabled
		 * @return true if debug logging is enabled, false if not
		 */
		isDebugEnabled: function () {
			return this.isLogLevelEnabled('debug');
		},

		/**
		 * Add the given entry to the log history. Check whether the highWaterMark has been reached, and fire an event if yes.
		 * @param {Object} entry entry to be added to the log history
		 * @hide
		 */
		addToLogHistory: function (entry) {

			if (!Aloha.settings.logHistory) {
				this.init();
			}

			// when maxEntries is set to something illegal, we do nothing (log history is disabled)
			// check whether the level is one we like to have logged
			if (Aloha.settings.logHistory.maxEntries <= 0 || !Aloha.settings.logHistory.levels[entry.level]) {

				return;
			}

			// first add the entry as last element to the history array
			this.logHistory.push(entry);

			// check whether the highWaterMark was reached, if so, fire an event
			if (!this.highWaterMarkReached) {

				if (this.logHistory.length >= Aloha.settings.logHistory.maxEntries * Aloha.settings.logHistory.highWaterMark / 100) {

					// fire the event
					Aloha.trigger('aloha-log-full');
					// set the flag (so we will not fire the event again until the logHistory is flushed)
					this.highWaterMarkReached = true;
				}
			}

			// check whether the log is full and eventually remove the oldest entries
			// @todo remove old entries when aloha-log-full event is triggered
			while (this.logHistory.length > Aloha.settings.logHistory.maxEntries) {
				this.logHistory.shift();
			}
		},

		/**
		 * Get the log history
		 * @return log history as array of objects
		 * @hide
		 */
		getLogHistory: function () {
			return this.logHistory;
		},

		/**
		 * Flush the log history. Remove all log entries and reset the flag for the highWaterMark
		 * @return void
		 * @hide
		 */
		flushLogHistory: function () {
			this.logHistory = [];
			this.highWaterMarkReached = false;
		}
	});

	/**
	 * Create the Log object
	 * @hide
	 */
	AlohaConsole = new AlohaConsole();

	// add to log namespace for compatiblility.
	Aloha.Log = Aloha.Console = AlohaConsole;
	return AlohaConsole;
});