// Total frames to record
var FRAMES_PER_GIF = 36;

// Frames per second to read from the video
var FPS = 12;

// Per-frame delay in milliseconds
var DELAY = Math.floor( 1000 / FPS );

// Number of WebWorkers to create
var WORKERS = 6;

// Number of frames to use to build the gif palette (takes longest)
var FRAMES_TO_QUANTIZE = 4;

// Upload these gifs when finished??
var DO_UPLOAD = true;

function GifEncoder(){
	var base = this;
  this.working = false;
  var canvases = [];
  var contexts = [];
  var frames = [];
  var delays = [];
  var width = 0;
  var height = 0;
  var frames_done = 0;

	var initted = Date.now();
	var started = Date.now();
	var tube = base.tube = new Tube ()
	
	var workers = new Factory ();

  var width, height;
  var neuquant, colortab;

	workers.hire("message", receiveMessage);
	workers.hire("quantize", receiveQuantize);
	workers.hire("encode", receiveEncode);

	var reset = this.reset = function(){
    resetFrames()
		neuquant = null;
		colortab = null;
		base.quantized = false
	}
	var resetFrames = this.resetFrames = function(){
		canvases = [];
		contexts = [];
		frames = [];
    delays = [];
    width = 0;
    height = 0;
    frames_done = 0;
	}

	this.on = function(){
    base.tube.on.apply(base.tube, arguments)
  };

  this.off = function(){
    base.tube.off.apply(base.tube, arguments)
  };

  var addFrame = this.addFrame = function(canvas, delay) {
    var ctx = canvas.getContext('2d');
		canvases.push(canvas);
    contexts.push(ctx);
    delays.push(delay);

    if (canvases.length == 1) {
      width = canvas.width;
      height = canvas.height;
    }
  }
  
  var addFrames = this.addFrames = function(canvas_array, delay){
    for (var i = 0; i < canvas_array.length; i++) {
      var canvas = canvas_array[i]
      var ctx = canvas.getContext('2d');
      canvases.push(canvas);
      contexts.push(ctx);
      delays.push(delay);
    }

    if (canvases.length == canvas_array.length) {
      width = canvas_array[0].width;
      height = canvas_array[0].height;
    }
  }

  var copyFrame = this.copyFrame = function(canvas, delay) {
    var newCanvas = document.createElement("canvas");
    var ctx = newCanvas.getContext('2d');
    
    ctx.drawImage(canvas, 0, 0, canvas.width, canvas.height);
    
		canvases.push(newCanvas);
    contexts.push(ctx);
    delays.push(delay);
    
    if (canvases.length == 1) {
      width = canvas.width;
      height = canvas.height;
    }
  }
  
	function Factory () {
		var base = this;
		var w = 0; // which worker to work next
    var ww = [];
		base.init = function(){
			for (var i = 0; i < WORKERS; i++) {
				// var worker = new Worker('js/vendor/gif-encode/worker.js');
				var worker = new Worker(workerURL);
				worker.onmessage = base.receiveWork;
				ww.push(worker);
			}
		}
		var tasks = {};
		base.hire = function(task, cb){
			tasks[task] = cb;
		}
		base.work = function(job){
			ww[++w % ww.length].postMessage(job);
		}
		base.receiveWork = function(e){
			e.data.task in tasks && tasks[e.data.task](e);
		}
		base.fire = function(){
		  for (var i in ww) {
		    ww[i].postMessage("close");
		  }
		  ww = []
		  base.init()	  
		}
		base.init();
	}

	function receiveMessage(e){
		console.log("[WORKER]", e.data.message);
	}
	
  var neuquant, colortab;
	var quantize = this.quantize = function () {
		initted = Date.now();
		started = Date.now();
		var spritedata = spriteSheet(FRAMES_TO_QUANTIZE);
		
		workers.work({
			task: 'quantize',
			imageData: spritedata
		});
	}

	function receiveQuantize(e) {
		console.log(Date.now() - started, "quantization done");
		neuquant = e.data.neuquant;
		colortab = e.data.colortab;
		base.quantized = true
		base.tube("quantized")
	}

	var encode = this.encode = function (nq, ct) {
    if (! canvases.length) {
      throw Error ("No frames to encode")
    }
	  nq = nq || neuquant
	  ct = ct || colortab

		started = Date.now();
    frames_done = 0;

		console.log('working .... ');
		var i = 0;

		function sendWork () {
			if (i == canvases.length) return doneSending();

			var ctx = contexts[i];
			var imdata = ctx.getImageData(0, 0, width, height).data;
			var delay = delays[i];

			workers.work({
				task: 'encode',
				frame_index: i,
				frame_length: contexts.length-1,
				height: height,
				width: width,
				delay: delay,
				imageData: imdata,
				neuquant: neuquant,
				colortab: colortab
			});

			i++;
			setTimeout(sendWork, 16);
		}
		function doneSending(){
		  base.tube("done_sending")
		}
		sendWork();
	}

	function receiveEncode(e){
		var frame_index = e.data["frame_index"];
		var frame_data = e.data["frame_data"];

		frames[frame_index] = frame_data;

    base.tube("encoded-frame", frames.length, canvases.length)
		for (var j = 0; j < canvases.length; j++) {
			if (frames[j] == null) {
				return;
			}
		}
		console.log("FINISHED " + canvases.length);
		var binary_gif = frames.join('');
		var base64_gif = window.btoa(binary_gif);
		var data_url = 'data:image/gif;base64,'+base64_gif;

		base.working = false;

		// photo.setAttribute('src', data_url);
		// ui.doneEncodingPicture();
    base.tube("rendered", binary_gif)
    base.tube("rendered-url", data_url)
// 		if (DO_UPLOAD) upload( base64_gif );

		console.log((Date.now() - started), "processed frames");
		console.log((Date.now() - initted), "done");
		
		workers.fire()
	}
	
// 	function upload (base64_gif) {
// 	  $("#working").html("UPLOADING")
// 	  	
//     console.log("starting upload")
// 		var params = {
// 			url: base64_gif
// 		}
//     $.ajax({
//       'url': "/photos.json",
//       'type': 'post',
//       'data': csrf(params),
//       'success': function(data){
// 
// //         $("#share").data("href", "/photos/" + data.hash)
// //         $("#share, #make-another").fadeIn(400);
// 				console.log(data);
// 				console.log((Date.now() - started), "uploaded");
// //         $("#photo").attr("src", data.url);
// //         window.location.href = "/photos/" + data.hash
//         localStorage.setItem('hash', data.hash)
//         window.location.href = "/"
//         // data.hash
//       }
//     });
// 		console.log("ok");
// 	}

	function spriteSheet (frameCount) {
		var start = Date.now();
		frameCount = Math.min(contexts.length, frameCount);
		var sprites = document.createElement("canvas");
		var spriteContext = sprites.getContext('2d');
		sprites.width = width;
		sprites.height = height * frameCount;
		var spritedata = spriteContext.getImageData(0, 0, sprites.width, sprites.height)
		var spritedatadata = spritedata.data
		var j = 0;
		var ctxz = sample(contexts, 4);
		while (frameCount--) {
			var ctx = ctxz[frameCount];
			var imdata = ctx.getImageData(0, 0, width, height).data;
			for (var n = 0; n < imdata.length; j++, n++) {
				spritedatadata[j] = imdata[n];
			}
		}
		// spriteContext.putImageData(spritedata, 0, 0, 0, 0, sprites.width, sprites.height);
		// upload( sprites.toDataURL("image/png").split(",")[1]
		console.log(Date.now() - start, "built spritesheet");
		return spritedata;
	}
 
}