// Skin locations are based on the work of Confuser, with 1.8 updates by Jake0oo0
// https://github.com/confuser/serverless-mc-skin-viewer
// Permission to use & distribute https://github.com/confuser/serverless-mc-skin-viewer/blob/master/LICENSE

var logging = require("./logging");
var fs = require("fs");
var Canvas = require("canvas");
var Image = Canvas.Image;
var exp = {};

// draws the helmet on to the +skin_canvas+
// using the skin from the +model_ctx+ at the +scale+
exp.draw_helmet = function(skin_canvas, model_ctx, scale) {
  //Helmet - Front
  model_ctx.setTransform(1,-0.5,0,1.2,0,0);
  model_ctx.drawImage(skin_canvas, 40*scale, 8*scale, 8*scale, 8*scale, 10*scale, 13/1.2*scale, 8*scale, 8*scale);
  //Helmet - Right
  model_ctx.setTransform(1,0.5,0,1.2,0,0);
  model_ctx.drawImage(skin_canvas, 32*scale, 8*scale, 8*scale, 8*scale, 2*scale, 3/1.2*scale, 8*scale, 8*scale);
  //Helmet - Top
  model_ctx.setTransform(-1,0.5,1,0.5,0,0);
  model_ctx.scale(-1,1);
  model_ctx.drawImage(skin_canvas, 40*scale, 0, 8*scale, 8*scale, -3*scale, 5*scale, 8*scale, 8*scale);
};

// draws the head on to the +skin_canvas+
// using the skin from the +model_ctx+ at the +scale+
exp.draw_head = function(skin_canvas, model_ctx, scale) {
  //Head - Front
  model_ctx.setTransform(1,-0.5,0,1.2,0,0);
  model_ctx.drawImage(skin_canvas, 8*scale, 8*scale, 8*scale, 8*scale, 10*scale, 13/1.2*scale, 8*scale, 8*scale);
  //Head - Right
  model_ctx.setTransform(1,0.5,0,1.2,0,0);
  model_ctx.drawImage(skin_canvas, 0, 8*scale, 8*scale, 8*scale, 2*scale, 3/1.2*scale, 8*scale, 8*scale);
  //Head - Top
  model_ctx.setTransform(-1,0.5,1,0.5,0,0);
  model_ctx.scale(-1,1);
  model_ctx.drawImage(skin_canvas, 8*scale, 0, 8*scale, 8*scale, -3*scale, 5*scale, 8*scale, 8*scale);
};

// draws the body on to the +skin_canvas+
// using the skin from the +model_ctx+ at the +scale+
// parts are labeled as if drawn from the skin's POV
exp.draw_body = function(rid, skin_canvas, model_ctx, scale) {
  if (skin_canvas.height === 32 * scale) {
    logging.debug(rid + "uses old skin format");
    //Left Leg
    //Left Leg - Front
    model_ctx.setTransform(1,-0.5,0,1.2,0,0);
    model_ctx.scale(-1,1);
    model_ctx.drawImage(skin_canvas, 4*scale, 20*scale, 4*scale, 12*scale, -16*scale, 34.4/1.2*scale, 4*scale, 12*scale);

    //Right Leg
    //Right Leg - Right
    model_ctx.setTransform(1,0.5,0,1.2,0,0);
    model_ctx.drawImage(skin_canvas, 0*scale, 20*scale, 4*scale, 12*scale, 4*scale, 26.4/1.2*scale, 4*scale, 12*scale);
    //Right Leg - Front
    model_ctx.setTransform(1,-0.5,0,1.2,0,0);
    model_ctx.drawImage(skin_canvas, 4*scale, 20*scale, 4*scale, 12*scale, 8*scale, 34.4/1.2*scale, 4*scale, 12*scale);

    //Arm Left
    //Arm Left - Front
    model_ctx.setTransform(1,-0.5,0,1.2,0,0);
    model_ctx.scale(-1,1);
    model_ctx.drawImage(skin_canvas, 44*scale, 20*scale, 4*scale, 12*scale, -20*scale, 20/1.2*scale, 4*scale, 12*scale);
    //Arm Left - Top
    model_ctx.setTransform(-1,0.5,1,0.5,0,0);
    model_ctx.drawImage(skin_canvas, 44*scale, 16*scale, 4*scale, 4*scale, 0, 16*scale, 4*scale, 4*scale);

    //Body
    //Body - Front
    model_ctx.setTransform(1,-0.5,0,1.2,0,0);
    model_ctx.drawImage(skin_canvas, 20*scale, 20*scale, 8*scale, 12*scale, 8*scale, 20/1.2*scale, 8*scale, 12*scale);

    //Arm Right
    //Arm Right - Right
    model_ctx.setTransform(1,0.5,0,1.2,0,0);
    model_ctx.drawImage(skin_canvas, 40*scale, 20*scale, 4*scale, 12*scale, 0, 16/1.2*scale, 4*scale, 12*scale);
    //Arm Right - Front
    model_ctx.setTransform(1,-0.5,0,1.2,0,0);
    model_ctx.drawImage(skin_canvas, 44*scale, 20*scale, 4*scale, 12*scale, 4*scale, 20/1.2*scale, 4*scale, 12*scale);
    //Arm Right - Top
    model_ctx.setTransform(-1,0.5,1,0.5,0,0);
    model_ctx.scale(-1,1);
    model_ctx.drawImage(skin_canvas, 44*scale, 16*scale, 4*scale, 4*scale, -16*scale, 16*scale, 4*scale, 4*scale);
  } else {
    logging.debug(rid + "uses new skin format");
    //Left Leg
    //Left Leg - Front
    model_ctx.setTransform(1,-0.5,0,1.2,0,0);
    model_ctx.drawImage(skin_canvas, 20*scale, 52*scale, 4*scale, 12*scale, 12*scale, 34.4/1.2*scale, 4*scale, 12*scale);

    //Right Leg
    //Right Leg - Right
    model_ctx.setTransform(1,0.5,0,1.2,0,0);
    model_ctx.drawImage(skin_canvas, 0, 20*scale, 4*scale, 12*scale, 4*scale, 26.4/1.2*scale, 4*scale, 12*scale);
    //Right Leg - Front
    model_ctx.setTransform(1,-0.5,0,1.2,0,0);
    model_ctx.drawImage(skin_canvas, 4*scale, 20*scale, 4*scale, 12*scale, 8*scale, 34.4/1.2*scale, 4*scale, 12*scale);

    //Arm Left
    //Arm Left - Front
    model_ctx.setTransform(1,-0.5,0,1.2,0,0);
    model_ctx.drawImage(skin_canvas, 36*scale, 52*scale, 4*scale, 12*scale, 16*scale, 20/1.2*scale, 4*scale, 12*scale);
    //Arm Left - Top
    model_ctx.setTransform(-1,0.5,1,0.5,0,0);
    model_ctx.drawImage(skin_canvas, 36*scale, 48*scale, 4*scale, 4*scale, 0, 16*scale, 4*scale, 4*scale);

    //Body
    //Body - Front
    model_ctx.setTransform(1,-0.5,0,1.2,0,0);
    model_ctx.drawImage(skin_canvas, 20*scale, 20*scale, 8*scale, 12*scale, 8*scale, 20/1.2*scale, 8*scale, 12*scale);

    //Arm Right
    //Arm Right - Right
    model_ctx.setTransform(1,0.5,0,1.2,0,0);
    model_ctx.drawImage(skin_canvas, 40*scale, 20*scale, 4*scale, 12*scale, 0, 16/1.2*scale, 4*scale, 12*scale);
    //Arm Right - Front
    model_ctx.setTransform(1,-0.5,0,1.2,0,0);
    model_ctx.drawImage(skin_canvas, 44*scale, 20*scale, 4*scale, 12*scale, 4*scale, 20/1.2*scale, 4*scale, 12*scale);
    //Arm Right - Top
    model_ctx.setTransform(-1,0.5,1,0.5,0,0);
    model_ctx.scale(-1,1);
    model_ctx.drawImage(skin_canvas, 44*scale, 16*scale, 4*scale, 4*scale, -16*scale, 16*scale, 4*scale, 4*scale);
  }
};

// sets up the necessary components to draw the skin model
// uses the +img+ skin with options of drawing
// the +helm+ and the +body+
// callback contains error, image buffer
exp.draw_model = function(rid, img, scale, helm, body, callback) {
  var image = new Image();

  image.onerror = function(err) {
    logging.error(rid + "render error: " + err.stack);
    callback(err, null);
  };

  image.onload = function() {
    var width = 64 * scale;
    var original_height = (image.height === 32 ? 32 : 64);
    var height = original_height * scale;
    var model_canvas = new Canvas(20 * scale, (body ? 44.8 : 17.6) * scale);
    var skin_canvas = new Canvas(width, height);
    var model_ctx = model_canvas.getContext("2d");
    var skin_ctx = skin_canvas.getContext("2d");

    skin_ctx.drawImage(image,0,0,64,original_height);
    //Scale it
    scale_image(skin_ctx.getImageData(0,0,64,original_height), skin_ctx, 0, 0, scale);
    if (body) {
      exp.draw_body(rid, skin_canvas, model_ctx, scale);
    }
    exp.draw_head(skin_canvas, model_ctx, scale);
    if (helm) {
      exp.draw_helmet(skin_canvas, model_ctx, scale);
    }

    model_canvas.toBuffer(function(err, buf){
      if (err) {
        logging.error(rid + "error creating buffer: " + err);
      }
      callback(err, buf);
    });
  };

  image.src = img;
};

// helper method to open a render from +renderpath+
// callback contains error, image buffer
exp.open_render = function(rid, renderpath, callback) {
  fs.readFile(renderpath, function (err, buf) {
    if (err) {
      logging.error(rid + "error while opening skin file: " + err);
    }
    callback(err, buf);
  });
};

// scales an image from the +imagedata+ onto the +context+
// scaled by a factor of +scale+ with options +d_x+ and +d_y+
function scale_image(imageData, context, d_x, d_y, scale) {
  var width = imageData.width;
  var height = imageData.height;
  context.clearRect(0,0,width,height); //Clear the spot where it originated from
  for(var y = 0; y < height; y++) { // height original
    for(var x = 0; x < width; x++) { // width original
      //Gets original colour, then makes a scaled square of the same colour
      var index = (x + y * width) * 4;
      context.fillStyle = "rgba(" + imageData.data[index+0] + "," + imageData.data[index+1] + "," + imageData.data[index+2] + "," + imageData.data[index+3] + ")";
      context.fillRect(d_x + x*scale, d_y + y*scale, scale, scale);
    }
  }
}

module.exports = exp;