/*
Copyright (c) 2012, Ger Hobbelt (ger@hobbelt.com)
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice, this
  list of conditions and the following disclaimer.

* Redistributions in binary form must reproduce the above copyright notice,
  this list of conditions and the following disclaimer in the documentation
  and/or other materials provided with the distribution.

* The name Ger Hobbelt may not be used to endorse or promote products
  derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL MICHAEL BOSTOCK BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

(function(){
/*
This software assumes that jDataview.js has been loaded alongside.

jDataview.js is (c) Copyright Christopher Chedeau and is available at
  https://github.com/vjeux/jDataView
and
  http://blog.vjeux.com/2011/javascript/jdataview-read-binary-file.html


Info sources consulted while preparing/building this software:

Adobe ASE (Color Swatches) format:

  http://www.selapa.net/swatches/colors/fileformats.php
  http://iamacamera.org/default.aspx?id=109

CMYK / LAB to RGB:

  http://www.easyrgb.com/index.php?X=MATH&H=12#text12
  http://www.codeproject.com/Articles/4488/XCmyk-CMYK-to-RGB-Calculator-with-source-code

Loading binary files in JavaScript:

  https://developer.mozilla.org/en/using_xmlhttprequest#Receiving_binary_data
  http://blog.vjeux.com/2011/javascript/jdataview-read-binary-file.html
  http://blog.vjeux.com/2010/javascript/javascript-binary-reader.html
  http://codereview.stackexchange.com/questions/3569/pack-and-unpack-bytes-to-strings
  http://stackoverflow.com/questions/1240408/reading-bytes-from-a-javascript-string

*/

adobe =
{
  ase: {version: "0.0.1"} // semver
};

adobe.ase.load = function(url, callback)
{
  d3.xhr(url, 'text/plain; charset=x-user-defined', function(req)
  {
    if (req)
    {
      console.log(req);
      var version_major, version_minor, count, i, view, palette = {}, flattened = [];

      try
      {
        view = new jDataView(req.response, 0, undefined, false); // big-endian format
      }
      catch(e)
      {
        view = null;
      }
      if (!view ||
          "ASEF" !== view.getString(4) ||
          (version_major = view.getInt16()) < 1 ||
          (version_minor = view.getInt16()) < 0 ||
          (count = view.getInt32()) < 1)
      {
        callback(null, null, "illegal file format, not a ASE color palette file");
      }

      function rgb2str(rgb)
      {
        var r, g, b;

        r = rgb[0].toString(16);
        if (r.length < 2)
          r = "0" + r;
        g = rgb[1].toString(16);
        if (g.length < 2)
          g = "0" + g;
        b = rgb[2].toString(16);
        if (b.length < 2)
          b = "0" + b;
        return "#" + r + g + b;
      }

      function parse_utf16_Cstring(view)
      {
        var slen = view.getUint16();
        var c, name = "", i = slen;
        // ignore NUL sentinel at the end of the string
        while (--i > 0) {
          c = view.getUint16();
          name += String.fromCharCode(c);
        }
        view.getUint16();
        return name;
      }

      function parse_block(view, palette)
      {
        // parse block:
        var i, id, len, slen, model, type, c, m, k, l, a, r, g, b, x, y, z, name, p;

        while (--count >= 0)
        {
          id = view.getUint16();
          switch (id)
          {
          default:
            // illegal block; damaged ASE file?
            callback(null, null, "unknown block type " + id.toString(16) + ": broken ASE color palette file");
            return -1;

          case 0xc001: // group start
            len = view.getUint32();
            name = parse_utf16_Cstring(view);
            if (!palette.groups)
              palette.groups = [];
            palette.groups.push(p = {
              name: name
            });
            if (parse_block(view, p))
              return -1;
            continue;

          case 0xc002: // group end
            view.getUint32(); // skip 0 length
            return 0;

          case 0x0001: // color
            len = view.getUint32();
            name = parse_utf16_Cstring(view);
            model = view.getString(4);
            if (!palette.colors)
              palette.colors = [];
            palette.colors.push(p = {
              name: name,
              model: model
            });
            switch (model)
            {
            case "CMYK":
              c = view.getFloat32();
              m = view.getFloat32();
              y = view.getFloat32();
              k = view.getFloat32();
              p.cmyk = [c, m, y, k];

              if (k >= 1)
              {
                //Black
                r = g = b = 0;
              }
              else
              {
                //CMYK and CMY values from 0 to 1
                c = c * (1 - k) + k;
                m = m * (1 - k) + k;
                y = y * (1 - k) + k;

                //CMY values from 0 to 1
                //RGB results from 0 to 255
                r = (1 - c);
                g = (1 - m);
                b = (1 - y);

                r = Math.min(255, Math.max(0, Math.round(r * 255)));
                g = Math.min(255, Math.max(0, Math.round(g * 255)));
                b = Math.min(255, Math.max(0, Math.round(b * 255)));
              }
              flattened.push(rgb2str(p.html_rgb = [r, g, b]));
              break;

            case "RGB ":
              r = view.getFloat32();
              g = view.getFloat32();
              b = view.getFloat32();
              p.rgb = [r, g, b];  // also keep the raw RGB

              r = Math.min(255, Math.max(0, Math.round(r * 255)));
              g = Math.min(255, Math.max(0, Math.round(g * 255)));
              b = Math.min(255, Math.max(0, Math.round(b * 255)));
              flattened.push(rgb2str(p.html_rgb = [r, g, b]));
              break;

            case "LAB ":
              l = view.getFloat32();
              a = view.getFloat32();
              b = view.getFloat32();
              p.lab = [l, a, b];

              // Photoshop CS5.5 saves these as perunage (0..1), value, value. So we need to adjust L before commencing:
              l *= 100;

              // CIE-L*ab -> XYZ
              y = (l + 16) / 116;
              x = a / 500 + y;
              z = y - b / 200;

              if (Math.pow(y, 3) > 0.008856)
                y = Math.pow(y, 3);
              else
                y = (y - 16 / 116) / 7.787;
              if (Math.pow(x, 3) > 0.008856)
                x = Math.pow(x, 3);
              else
                x = (x - 16 / 116) / 7.787;
              if (Math.pow(z, 3) > 0.008856)
                z = Math.pow(z, 3);
              else
                z = (z - 16 / 116) / 7.787;

              x = 95.047 * x;      //ref_X =  95.047     Observer= 2°, Illuminant= D65
              y = 100.000 * y;     //ref_Y = 100.000
              z = 108.883 * z;     //ref_Z = 108.883

              // XYZ -> RGB
              x = x / 100;        //X from 0 to  95.047      (Observer = 2°, Illuminant = D65)
              y = y / 100;        //Y from 0 to 100.000
              z = z / 100;        //Z from 0 to 108.883

              r = x *  3.2406 + y * -1.5372 + z * -0.4986;
              g = x * -0.9689 + y *  1.8758 + z *  0.0415;
              b = x *  0.0557 + y * -0.2040 + z *  1.0570;

              if (r > 0.0031308)
                r = 1.055 * Math.pow(r, 1 / 2.4) - 0.055;
              else
                r = 12.92 * r;
              if (g > 0.0031308)
                g = 1.055 * Math.pow(g, 1 / 2.4) - 0.055;
              else
                g = 12.92 * g;
              if (b > 0.0031308)
                b = 1.055 * Math.pow(b, 1 / 2.4) - 0.055;
              else
                b = 12.92 * b;

              r = Math.min(255, Math.max(0, Math.round(r * 255)));
              g = Math.min(255, Math.max(0, Math.round(g * 255)));
              b = Math.min(255, Math.max(0, Math.round(b * 255)));
              flattened.push(rgb2str(p.html_rgb = [r, g, b]));
              break;

            case "GRAY":
              g = view.getFloat32();
              p.gray = g;

              g = Math.min(255, Math.max(0, Math.round(g * 255)));
              flattened.push(rgb2str(p.html_rgb = [g, g, g]));
              break;

            default:
              callback(null, null, "unknown color model " + model + ": broken ASE color palette file");
              return -1;
            }
            type = view.getUint16();
            p.color_type = type; // (0 => Global, 1 => Spot, 2 => Normal)
            continue;
          }
        }
        return 0;
      }

      if (!parse_block(view, palette))
        callback(palette, flattened);
    } else {
      callback(null, null, "I/O error: could not load ASE palette file");
    }
  });
};

})();