using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.IO;
using System.Drawing;

namespace GamesVerwaltung
{
    class MultiIcon
    {
        private struct TIconHeader
        {
            public short res0;
            public short imgtype;
            public short imgcount;
        }
        private struct TIconData
        {
            public byte width;
            public byte height;
            public byte clcount;
            public byte res0;
            public short clplanes;
            public short bpp;
            public int imglen;
            public int imgadr;
        }

        private Bitmap[] bitmaps;
        private TIconData[] icondata;
        private TIconHeader iconheader;

        public MultiIcon()
        {
            bitmaps = new Bitmap[6];
            icondata = new TIconData[6];

            iconheader = new TIconHeader();
            iconheader.imgcount = 6;
            iconheader.imgtype = 1;
            iconheader.res0 = 0;
        }

        private void setImage(int idx, Bitmap bmp)
        {
            bitmaps[idx] = bmp;

            icondata[idx].bpp = 32;
            icondata[idx].clcount = 0;
            icondata[idx].clplanes = 0;
            icondata[idx].height = (byte)(bmp.Height == 256 ? 0 : bmp.Height);
            icondata[idx].width = (byte)(bmp.Width == 256 ? 0 : bmp.Width);
            icondata[idx].res0 = 0;
            icondata[idx].imgadr = -1;
            icondata[idx].imglen = -1;
        }

        public void SetAll(Image img)
        {
            setImage(0, createHighRes(img, 16, 16));
            setImage(1, createHighRes(img, 24, 24));
            setImage(2, createHighRes(img, 32, 32));
            setImage(3, createHighRes(img, 48, 48));
            setImage(4, createHighRes(img, 128, 128));
            setImage(5, createHighRes(img, 256, 256));
        }

        public void Save(string file)
        {
            FileStream fstr = new FileStream(file, FileMode.Create, FileAccess.Write);
            writeIcon(fstr);
            fstr.Close();
            fstr.Dispose();
        }

        private void writeIcon(Stream str)
        {
            BinaryWriter bw = new BinaryWriter(str);

            bw.Write(iconheader.res0);
            bw.Write(iconheader.imgtype);
            bw.Write(iconheader.imgcount);

            int offset = 6 /*ANZAHL DER BILDER*/ * 16 /*BYTEGRÖßE ICONHEADER*/;
            int iconheader0offset = (int)str.Position;
            str.Position += offset;

            for (int i = 0; i < 6; i++)
            {
                Bitmap bmp = bitmaps[i];

                //MemoryStream mstr = new MemoryStream();
                icondata[i].imgadr = (int)str.Position;
                bmp.Save(str, System.Drawing.Imaging.ImageFormat.Png);
                icondata[i].imglen = (int)(str.Position - icondata[i].imgadr);
            }

            str.Position = iconheader0offset;

            for (int i = 0; i < 6; i++)
            {
                TIconData idat = icondata[i];
                /*
                    0 	1 	Specifies image width in pixels. Can be 0, 255 or a number between 0 to 255. Should be 0 if image width is 256 pixels.
                    1 	1 	Specifies image height in pixels. Can be 0, 255 or a number between 0 to 255. Should be 0 if image height is 256 pixels.
                    2 	1 	Specifies number of colors in the color palette. Should be 0 if the image is truecolor.
                    3 	1 	Reserved. Should be 0.[Notes 1]
                    4 	2 	In .ICO format: Specifies color planes. Should be 0 or 1.[Notes 2]
                    6 	2 	In .ICO format: Specifies bits per pixel. [Notes 3]
                    8 	4 	Specifies the size of the bitmap data in bytes
                    12 	4 	Specifies the offset of bitmap data address in the file
                */
                bw.Write(idat.width);
                bw.Write(idat.height);
                bw.Write(idat.clcount);
                bw.Write(idat.res0);
                bw.Write(idat.clplanes);
                bw.Write(idat.bpp);
                bw.Write(idat.imglen);
                bw.Write(idat.imgadr);
            }
        }

        private Bitmap createHighRes(Image img, int w, int h)
        {
            Bitmap bmp = new Bitmap(w, h);

            Graphics dc = Graphics.FromImage(bmp);
            dc.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
            dc.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
            dc.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
            dc.DrawImage(img, 0, 0, w, h);
            dc.Dispose();

            return bmp;
        }
    }
}