"use strict";

var palette;

function PixelEditor(parentDiv, fmt, palette, initialData, thumbnails) {
  var self = this;
  var width = fmt.w;
  var height = fmt.h;

  function createCanvas(parent) {
    var c = document.createElement('canvas');
    c.width = width;
    c.height = height;
    if (fmt.xform) c.style.transform = fmt.xform;
    c.classList.add("pixels");
    c.classList.add("pixelated");
    //canvas.tabIndex = "-1";               // Make it focusable
    $(parentDiv).empty().append(c);
    return c;
  }

  function updateImage() {
    ctx.putImageData(pixdata, 0, 0);
  }

  function updateThumbnails() {
    if (!thumbnails) return;
    for (var i=0; i<thumbnails.length; i++) {
      thumbnails[i].copyImageFrom(self);
    }
  }

  this.copyImageFrom = function(src) {
    pixints.set(src.getImageData());
    updateImage();
  }

  this.getImageData = function() { return pixints; }

  function fitCanvas() {
    var w = $(parentDiv).width();
    var h = $(parentDiv).height();
    pixcanvas.style.height = Math.floor(h)+"px";
    // TODO
  }
  this.resize = fitCanvas;

  var pixcanvas = createCanvas();
  var ctx = pixcanvas.getContext('2d');
  var pixdata = ctx.createImageData(width, height);
  var pixints = new Uint32Array(pixdata.data.buffer);
  for (var i=0; i<pixints.length; i++) {
    pixints[i] = initialData ? palette[initialData[i]] : palette[0];
  }

  updateImage();

  function revrgb(x) {
    var y = 0;
    y |= ((x >> 0) & 0xff) << 16;
    y |= ((x >> 8) & 0xff) << 8;
    y |= ((x >> 16) & 0xff) << 0;
    return y;
  }

  this.createPaletteButtons = function() {
    var span = $("#palette_group").empty();
    for (var i=0; i<palette.length; i++) {
      var btn = $('<button class="palbtn">');
      var rgb = palette[i] & 0xffffff;
      var color = "#" + hex(revrgb(rgb), 6);
      btn.click(self.setCurrentColor.bind(this, i));
      btn.attr('id', 'palcol_' + i);
      btn.css('backgroundColor', color).text(i.toString(16));
      if ((rgb & 0x808080) != 0x808080) { btn.css('color', 'white'); }
      span.append(btn);
    }
    self.setCurrentColor(1);
  }

  function getPixelByOffset(ofs) {
    var oldrgba = pixints[ofs] & 0xffffff;
    for (var i=0; i<palette.length; i++) {
      if (oldrgba == (palette[i] & 0xffffff)) return i;
    }
    return 0;
  }

  function getPixel(x, y) {
    var ofs = x+y*width;
    return getPixelByOffset(ofs);
  }

  function setPixel(x, y, col) {
    if (x < 0 || x >= width || y < 0 || y >= height) return;
    var ofs = x+y*width;
    var oldrgba = pixints[ofs];
    var rgba = palette[col];
    if (oldrgba != rgba) {
      pixints[ofs] = rgba;
      updateImage();
    }
  }

  this.getImageColors = function() {
    var pixcols = new Uint8Array(pixints.length);
    for (var i=0; i<pixints.length; i++)
      pixcols[i] = getPixelByOffset(i);
    return pixcols;
  }

  ///

  this.makeEditable = function() {
    var curpalcol = -1;
    setCurrentColor(1);

    function getPositionFromEvent(e) {
      var x = Math.floor(e.offsetX * width / pxls.width());
      var y = Math.floor(e.offsetY * height / pxls.height());
      return {x:x, y:y};
    }

    function setCurrentColor(col) {
      if (curpalcol != col) {
        if (curpalcol >= 0)
          $("#palcol_" + curpalcol).removeClass('selected');
        curpalcol = col;
        $("#palcol_" + col).addClass('selected');
      }
    }
    self.setCurrentColor = setCurrentColor;

    var dragcol = 1;
    var dragging = false;

    var pxls = $(pixcanvas);
    pxls.mousedown(function(e) {
      var pos = getPositionFromEvent(e);
      dragcol = getPixel(pos.x, pos.y) == curpalcol ? 0 : curpalcol;
      setPixel(pos.x, pos.y, curpalcol);
      dragging = true;
      pixcanvas.setCapture();
    })
    .mousemove(function(e) {
      var pos = getPositionFromEvent(e);
      if (dragging) {
        setPixel(pos.x, pos.y, dragcol);
      }
    })
    .mouseup(function(e) {
      var pos = getPositionFromEvent(e);
      setPixel(pos.x, pos.y, dragcol);
      dragging = false;
      updateThumbnails();
      pixcanvas.releaseCapture();
    });
  }
}

/////////////////

var pixel_re = /([0#]?)([x$%])([0-9a-f]+)/gi;

function parseHexBytes(s) {
  var arr = [];
  var m;
  while (m = pixel_re.exec(s)) {
    var n;
    if (m[2].startsWith('%'))
      n = parseInt(m[3],2);
    else if (m[2].startsWith('x') || m[2].startsWith('$'))
      n = parseInt(m[3],16);
    else
      n = parseInt(m[3]);
    arr.push(n);
  }
  return arr;
}

function replaceHexBytes(s, bytes) {
  var result = "";
  var m;
  var li = 0;
  var i = 0;
  while (m = pixel_re.exec(s)) {
    result += s.slice(li, pixel_re.lastIndex - m[0].length);
    li = pixel_re.lastIndex;
    if (m[2].startsWith('%'))
      result += m[1] + "%" + bytes[i++].toString(2);
    else if (m[2].startsWith('x'))
      result += m[1] + "x" + hex(bytes[i++]);
    else if (m[2].startsWith('$'))
      result += m[1] + "$" + hex(bytes[i++]);
    else
      result += m[1] + bytes[i++].toString();
  }
  result += s.slice(li);
  return result;
}

function remapBits(x, arr) {
  if (!arr) return x;
  var y = 0;
  for (var i=0; i<arr.length; i++) {
    var s = arr[i];
    if (s < 0) {
      s = -s-1;
      y ^= 1 << s;
    }
    if (x & (1 << i)) {
      y ^= 1 << s;
    }
  }
  return y;
}

function convertBytesToImages(bytes, fmt) {
  var width = fmt.w;
  var height = fmt.h;
  var count = fmt.count || 1;
  var bpp = fmt.bpp || 1;
  var nplanes = fmt.np || 1;
  var bytesperline = fmt.sl || Math.ceil(width * bpp / 8);
  var mask = (1 << bpp)-1;
  var images = [];
  for (var n=0; n<count; n++) {
    var imgdata = [];
    for (var y=0; y<height; y++) {
      var ofs0 = n*bytesperline*height + y*bytesperline;
      var shift = 0;
      for (var x=0; x<width; x++) {
        var color = 0;
        var ofs = remapBits(ofs0, fmt.remap);
        for (var p=0; p<nplanes; p++) {
          var byte = bytes[ofs + p*(fmt.pofs|0)];
          color |= ((fmt.brev ? byte>>(8-shift-bpp) : byte>>shift) & mask) << (p*bpp);
        }
        imgdata.push(color);
        shift += bpp;
        if (shift >= 8) {
          ofs0 += 1;
          shift = 0;
        }
      }
    }
    images.push(imgdata);
  }
  return images;
}

function convertImagesToBytes(images, fmt) {
  var width = fmt.w;
  var height = fmt.h;
  var count = fmt.count || 1;
  var bpp = fmt.bpp || 1;
  var nplanes = fmt.np || 1;
  var bytesperline = fmt.sl || Math.ceil(fmt.w * bpp / 8);
  var mask = (1 << bpp)-1;
  var bytes = new Uint8Array(bytesperline * height * nplanes * count);
  for (var n=0; n<count; n++) {
    var imgdata = images[n];
    var i = 0;
    for (var y=0; y<height; y++) {
      var ofs0 = n*bytesperline*height + y*bytesperline;
      var shift = 0;
      for (var x=0; x<width; x++) {
        var color = imgdata[i++];
        var ofs = remapBits(ofs0, fmt.remap);
        for (var p=0; p<nplanes; p++) {
          var c = (color >> (p*bpp)) & mask;
          bytes[ofs + p*(fmt.pofs|0)] |= (fmt.brev ? (c << (8-shift-bpp)) : (c << shift));
        }
        shift += bpp;
        if (shift >= 8) {
          ofs0 += 1;
          shift = 0;
        }
      }
    }
  }
  return bytes;
}

function convertPaletteBytes(arr,r0,r1,g0,g1,b0,b1) {
  var result = [];
  for (var i=0; i<arr.length; i++) {
    var d = arr[i];
    var rgb = 0xff000000;
    rgb |= ((d >> r0) & ((1<<r1)-1)) << (0+8-r1);
    rgb |= ((d >> g0) & ((1<<g1)-1)) << (8+8-g1);
    rgb |= ((d >> b0) & ((1<<b1)-1)) << (16+8-b1);
    result.push(rgb);
  }
  return result;
}

var currentPixelEditor;
var parentSource;
var parentOrigin;
var allimages;
var currentFormat;
var currentByteStr;
var currentPaletteStr;
var currentPaletteFmt;
var allthumbs;

function pixelEditorDecodeMessage(e) {
  console.log(e.data);
  parentSource = e.source;
  parentOrigin = e.origin;
  currentFormat = e.data.fmt;
  currentByteStr = e.data.bytestr;
  currentPaletteFmt = e.data.palfmt;
  currentPaletteStr = e.data.palstr;
  var bytes = parseHexBytes(e.data.bytestr);
  allimages = convertBytesToImages(bytes, e.data.fmt);
  palette = [0xff000000, 0xffffffff]; // TODO
  if (currentPaletteStr) {
    var palbytes = parseHexBytes(e.data.palstr);
    var rr = Math.floor(Math.abs(currentPaletteFmt.pal/100) % 10);
    var gg = Math.floor(Math.abs(currentPaletteFmt.pal/10) % 10);
    var bb = Math.floor(Math.abs(currentPaletteFmt.pal) % 10);
    // TODO: n
    if (currentPaletteFmt.pal >= 0)
      palette = convertPaletteBytes(palbytes, 0, rr, rr, gg, rr+gg, bb);
    else
      palette = convertPaletteBytes(palbytes, rr+gg, bb, rr, gg, 0, rr);
  } else {
    // TODO: default palette?
  }
  palette = new Uint32Array(palette);
}

function pixelEditorCreateThumbnails(e) {
  // create thumbnail for all images
  $("#thumbnaildiv").empty();
  var parentdiv;
  var count = e.data.fmt.count || 1;
  allthumbs = [];
  for (var i=0; i<count; i++) {
    if ((i & 15) == 0) {
      parentdiv = $("#thumbnaildiv").append("<div>");
    }
    allthumbs.push(createThumbnailForImage(parentdiv, i));
  }
}

function pixelEditorReceiveMessage(e) {
  pixelEditorDecodeMessage(e);
  pixelEditorCreateThumbnails(e);
  // create initial editor
  createEditorForImage(0);
}

function createThumbnailForImage(parentdiv, i) {
  var span = $('<span class="thumb">');
  var thumb = new PixelEditor(span, currentFormat, palette, allimages[i]);
  parentdiv.append(span);
  span.click(function() { createEditorForImage(i) });
  return thumb;
}

function createEditorForImage(i) {
  currentPixelEditor = new PixelEditor(maineditor, currentFormat, palette, allimages[i], [allthumbs[i]]);
  currentPixelEditor.resize();
  currentPixelEditor.makeEditable();
  currentPixelEditor.createPaletteButtons();
}

function postToParentWindow(data) {
  if (data.save) {
    var allimgs = [];
    for (var i=0; i<allthumbs.length; i++) {
      allimgs.push(allthumbs[i].getImageColors());
    }
    data.bytes = convertImagesToBytes(allimgs, currentFormat);
    data.bytestr = replaceHexBytes(currentByteStr, data.bytes);
  }
  if (parentSource) parentSource.postMessage(data, "*");
  return data;
}

function pixelEditorResize(e) {
  if (currentPixelEditor) {
    currentPixelEditor.resize();
  }
}

function pixelEditorKeypress(e) {
  if (!currentPixelEditor) return;
  var c = e.charCode;
  if (c >= 48 && c <= 57) {
    currentPixelEditor.setCurrentColor(c-48);
  } else if (c >= 97 && c <= 102) {
    currentPixelEditor.setCurrentColor(c-97+10);
  }
}