/*\
title: $:/core/modules/utils/logger.js
type: application/javascript
module-type: utils

A basic logging implementation

\*/
(function(){

/*jslint node: true, browser: true */
/*global $tw: false */
"use strict";

var ALERT_TAG = "$:/tags/Alert";

/*
Make a new logger
componentName: logger name, eg: "filesystem" as found in: $:/plugins/tiddlywiki/filesystem/filesystemadaptor.js
Options:
- colour ... default colour used to style text output
- enable ... default: true - logger is enabled
- save ... default: true - message will be saved to buffer
- saveLimit ... default 100kByte - limit buffer size
*/
function Logger(componentName,options) {
	options = options || {};
	this.componentName = componentName || "";
	this.colour = options.colour || "white";
	this.enable = "enable" in options ? options.enable : true;
	this.save = "save" in options ? options.save : true;
	this.saveLimit = options.saveLimit || 100 * 1024;
	this.saveBufferLogger = this;
	this.buffer = "";
	this.alertCount = 0;
}

Logger.prototype.setSaveBuffer = function(logger) {
	this.saveBufferLogger = logger;
};

Logger.prototype.writeToBuffer = function(/* args */) {
	var self = this;
	this.saveBufferLogger.buffer += $tw.utils.formatDateString(new Date(),"YYYY-0MM-0DD 0hh:0mm:0ss.0XXX") + " #";
	$tw.utils.each(Array.prototype.slice.call(arguments,0),function(arg,index) {
		self.saveBufferLogger.buffer += " " + arg.join(" - ");
	});
	this.saveBufferLogger.buffer += "\n";
	this.saveBufferLogger.buffer = this.saveBufferLogger.buffer.slice(-this.saveBufferLogger.saveLimit);
};

/*
Log a message
*/
Logger.prototype.log = function(/* args */) {
	if(this.enable) {
		if(this.saveBufferLogger.save) {
			this.writeToBuffer(Array.prototype.slice.call(arguments,0));
		}
		if(console !== undefined && console.log !== undefined) {
			var logMessage = [$tw.utils.terminalColour(this.colour) + this.componentName + ":"].concat(Array.prototype.slice.call(arguments,0));
			logMessage[logMessage.length-1] += $tw.utils.terminalColour();
			return Function.apply.call(console.log, console, logMessage);
		}
	}
};

/*
Log an "error" message to console.error so it also gets a red colour in browsers
*/
Logger.prototype.error = function(/* args */) {
	if(this.enable) {
		if(this.saveBufferLogger.save) {
			this.writeToBuffer(Array.prototype.slice.call(arguments,0));
		}
		if(console !== undefined && console.error !== undefined) {
			var logMessage = [$tw.utils.terminalColour("red") + this.componentName + ":"].concat(Array.prototype.slice.call(arguments,0));
			logMessage[logMessage.length-1] += $tw.utils.terminalColour();
			return Function.apply.call(console.error, console, logMessage);
		}
	}
};

/*
Log an "info" message to console.info so it also gets an (i) info icon in front
*/
Logger.prototype.info = function(/* args */) {
	if(this.enable) {
		if(this.saveBufferLogger.save) {
			this.writeToBuffer(Array.prototype.slice.call(arguments,0));
		}
		if(console !== undefined && console.info !== undefined) {
			var logMessage = [$tw.utils.terminalColour(this.colour) + this.componentName + ":"].concat(Array.prototype.slice.call(arguments,0));
			logMessage[logMessage.length-1] += $tw.utils.terminalColour();
			return Function.apply.call(console.info, console, logMessage);
		}
	}
};

/*
Log an "warning" message to console.info so it also gets an (!) warning icon in front
*/
Logger.prototype.warn = function(/* args */) {
	if(this.enable) {
		if(this.saveBufferLogger.save) {
			this.writeToBuffer(Array.prototype.slice.call(arguments,0));
		}
		if(console !== undefined && console.warn !== undefined) {
			var logMessage = [$tw.utils.terminalColour("orange") + this.componentName + ":"].concat(Array.prototype.slice.call(arguments,0));
			logMessage[logMessage.length-1] += $tw.utils.terminalColour();
			return Function.apply.call(console.warn, console, logMessage);
		}
	}
};

/*
Read the message buffer
*/
Logger.prototype.getBuffer = function() {
	return this.saveBufferLogger.buffer;
};

/*
Clear the message buffer
*/
Logger.prototype.clearBuffer = function() {
	this.saveBufferLogger.buffer = "";
};

/*
Log a structure as a table
*/
Logger.prototype.table = function(value) {
	(console.table || console.log)(value);
};

/*
Alert a message
*/
Logger.prototype.alert = function(/* args */) {
	if(this.enable) {
		// Prepare the text of the alert
		var text = Array.prototype.join.call(arguments," ");
		// Create alert tiddlers in the browser
		if($tw.browser) {
			// Check if there is an existing alert with the same text and the same component
			var existingAlerts = $tw.wiki.getTiddlersWithTag(ALERT_TAG),
				alertFields,
				existingCount,
				self = this;
			$tw.utils.each(existingAlerts,function(title) {
				var tiddler = $tw.wiki.getTiddler(title);
				if(tiddler.fields.text === text && tiddler.fields.component === self.componentName && tiddler.fields.modified && (!alertFields || tiddler.fields.modified < alertFields.modified)) {
						alertFields = $tw.utils.extend({},tiddler.fields);
				}
			});
			if(alertFields) {
				existingCount = alertFields.count || 1;
			} else {
				alertFields = {
					title: $tw.wiki.generateNewTitle("$:/temp/alerts/alert",{prefix: ""}),
					text: text,
					tags: [ALERT_TAG],
					component: this.componentName
				};
				existingCount = 0;
				this.alertCount += 1;
			}
			alertFields.modified = new Date();
			if(++existingCount > 1) {
				alertFields.count = existingCount;
			} else {
				alertFields.count = undefined;
			}
			$tw.wiki.addTiddler(new $tw.Tiddler(alertFields));
			// Log the alert as well
			this.log.apply(this,Array.prototype.slice.call(arguments,0));
		} else {
			// Print an orange message to the console if not in the browser
			console.error("\x1b[1;33m" + text + "\x1b[0m");
		}
	}
};

/*
Clear outstanding alerts
*/
Logger.prototype.clearAlerts = function() {
	var self = this;
	if($tw.browser && this.alertCount > 0) {
		$tw.utils.each($tw.wiki.getTiddlersWithTag(ALERT_TAG),function(title) {
			var tiddler = $tw.wiki.getTiddler(title);
			if(tiddler.fields.component === self.componentName) {
				$tw.wiki.deleteTiddler(title);
			}
		});
		this.alertCount = 0;
	}
};

exports.Logger = Logger;

})();