if (!Date.now) {
	Date.now = function() {
		return (new Date()).getTime();
	};
}


var StatsD = (function($, undefined) {

	var activeTimers = { };
	var queuedData = [ ];
	var flushTimer = undefined;

	var configOpts = {
		url: '/statsd',
		flushInterval: 1000
	};

	/**
	 * Update the client configuration of StatsD.
	 * @param opts an object containing new configuration values
	 */
	function config(opts) {
		$.extend(configOpts, opts);
	}

	/**
	 * Update a stat by an arbitrary amount.
	 * @param {String} stat the name of the stat to update
	 * @param {Number} delta the amount to update the stat by
	 * @param {Number} [sampleRate] a number between 0 and 1 indicating what percentage of this stat to sample
	 */
	function update(stat, delta, sampleRate) {
		queue(stat, delta+"|c", sampleRate);
	}

	/**
	 * Increment a stat by 1.
	 * @param {String} stat the name of the stat to update
	 * @param {Number} [sampleRate] a number between 0 and 1 indicating what percentage of this stat to sample
	 */
	function increment(stat, sampleRate) {
		update(stat, 1, sampleRate);
	}

	/**
	 * Decrement a stat by 1.
	 * @param {String} stat the name of the stat to update
	 * @param {Number} [sampleRate] a number between 0 and 1 indicating what percentage of this stat to sample
	 */
	function decrement(stat, sampleRate) {
		update(stat, -1, sampleRate);
	}

	/**
	 * Log timing information.
	 * @param {String} stat the name of the stat to update
	 * @param {Number} ms the time (in ms) to log
	 * @param {Number} [sampleRate] a number between 0 and 1 indicating what percentage of this stat to record
	 */
	function timing(stat, ms, sampleRate) {
		send(stat, ms+"|ms", sampleRate);
	}

	/**
	 * Start a timer that, when completed with stopTiming(), will log timing information.
	 * @param {String} stat the name of the stat to update
	 */
	function startTiming(stat) {
		activeTimers[stat] = Date.now();
	}

	/**
	 * Stop a running timer and log the amount of time (in ms) since it was started.
	 * @param {String} stat the name of the stat to update
	 * @param {Number} [sampleRate] a number between 0 and 1 indicating what percentage of this stat to sample
	 */
	function stopTiming(stat, sampleRate) {
		var start = activeTimers[stat];
		delete activeTimers[stat];
		if (start) {
			timing(stat, Date.now() - start);
		}
	}

	/**
	 * Queues up a piece of StatsD data to be sent to the server.
	 * @param {String} method the type of data that is being queues
	 * @param {String} stat the name of the stat being queued
	 * @param {String} value the value of the stat being queued
	 * @param {Number} [sampleRate] a number between 0 and 1 indicating what percentage of this stat to sample
	 */
	function queue(stat, value, sampleRate) {
		var data = stat+":"+value;

		if (sampleRate !== undefined && sampleRate != 1) {
			if (sampleRate < Math.random()) {
				return;
			}
			data = data+"|@"+sampleRate;
		}

		queuedData.push(data);

		if (configOpts.flushInterval <= 0) {
			flush();
		} else if (!flushTimer) {
			flushTimer = setTimeout(flush, configOpts.flushInterval);
		}
	}

	/**
	 * Send any queued StatsD data to the server. This data is
	 * automatically sent at a regular interval specificed by the
	 * flushInterval config setting.
	 */
	function flush() {
		clearTimeout(flushTimer);
		flushTimer = 0;

		var data = queuedData.join('\n');
		queuedData.splice(0, queuedData.length);

		$.ajax({
			type: "POST",
			url: configOpts.url,
			contentType: 'text/plain',
			data: data
		});
	}

	return {
		config: config,
		update: update,
		increment: increment,
		decrement: decrement,
		timing: timing,
		startTiming: startTiming,
		stopTiming: stopTiming,
		flush: flush
	};

})(jQuery);