/*

   This Source Code Form is subject to the terms of the Mozilla Public

   License, v. 2.0. If a copy of the MPL was not distributed with this

   file, You can obtain one at http://mozilla.org/MPL/2.0/.

   Copyright (C) 2009-2012 Michael Möller <mmoeller@openhardwaremonitor.org>

 */

 using System;

 using System.Collections.Generic;

 using System.Drawing;

 using System.Drawing.Imaging;

 using System.IO;

 using System.Text;

 namespace OpenHardwareMonitor.Utilities {

   public class IconFactory {

     private struct BITMAPINFOHEADER {

       public uint Size;

       public int Width;

       public int Height;

       public ushort Planes;

       public ushort BitCount;

       public uint Compression;

       public uint SizeImage;

       public int XPelsPerMeter;

       public int YPelsPerMeter;

       public uint ClrUsed;

       public uint ClrImportant;

       public BITMAPINFOHEADER(int width, int height, int bitCount) {

         this.Size = 40;

         this.Width = width;

         this.Height = height;

         this.Planes = 1;

         this.BitCount = (ushort)bitCount;

         this.Compression = 0;

         this.SizeImage = 0;

         this.XPelsPerMeter = 0;

         this.YPelsPerMeter = 0;

         this.ClrUsed = 0;

         this.ClrImportant = 0;

       }

       public void Write(BinaryWriter bw) {

         bw.Write(Size);

 			  bw.Write(Width);

 			  bw.Write(Height);

 			  bw.Write(Planes);

 			  bw.Write(BitCount);

 			  bw.Write(Compression);

 			  bw.Write(SizeImage);

 			  bw.Write(XPelsPerMeter);

 			  bw.Write(YPelsPerMeter);

 			  bw.Write(ClrUsed);

 			  bw.Write(ClrImportant);

       }

     }

     private struct ICONIMAGE {

       public BITMAPINFOHEADER Header;

       public byte[] Colors;

       public int MaskSize;

       public ICONIMAGE(int width, int height, byte[] colors) {

         this.Header = new BITMAPINFOHEADER(width, height << 1, 

           (8 * colors.Length) / (width * height));

         this.Colors = colors;

         MaskSize = (width * height) >> 3;

       }

       public void Write(BinaryWriter bw) {

         Header.Write(bw);

         int stride = Header.Width << 2;

         for (int i = (Header.Height >> 1) - 1; i >= 0; i--)

           bw.Write(Colors, i * stride, stride);

         for (int i = 0; i < 2 * MaskSize; i++)

           bw.Write((byte)0);        

       }

     }

     private struct ICONDIRENTRY {

       public byte Width;

       public byte Height;

       public byte ColorCount;

       public byte Reserved;

       public ushort Planes;

       public ushort BitCount;

       public uint BytesInRes;

       public uint ImageOffset;

       public ICONDIRENTRY(ICONIMAGE image, int imageOffset) {

         this.Width = (byte)image.Header.Width;

         this.Height = (byte)(image.Header.Height >> 1);

         this.ColorCount = 0;

         this.Reserved = 0;

         this.Planes = image.Header.Planes;

         this.BitCount = image.Header.BitCount;

         this.BytesInRes = (uint)(image.Header.Size +

           image.Colors.Length + image.MaskSize + image.MaskSize);

         this.ImageOffset = (uint)imageOffset;

       }

       public void Write(BinaryWriter bw) {

         bw.Write(Width);

         bw.Write(Height);

         bw.Write(ColorCount);

         bw.Write(Reserved);

         bw.Write(Planes);

         bw.Write(BitCount);

         bw.Write(BytesInRes);

         bw.Write(ImageOffset);

       }

       public uint Size {

         get { return 16; }

       }

     }

     private struct ICONDIR {

       public ushort Reserved;

       public ushort Type;

       public ushort Count;

       public ICONDIRENTRY[] Entries;

       public ICONDIR(ICONDIRENTRY[] entries) {

         this.Reserved = 0;

         this.Type = 1;

         this.Count = (ushort)entries.Length;

         this.Entries = entries;

       }

       public void Write(BinaryWriter bw) {

         bw.Write(Reserved);

         bw.Write(Type);

         bw.Write(Count);

         for (int i = 0; i < Entries.Length; i++)

           Entries[i].Write(bw);

       }

       public uint Size {

         get { return (uint)(6 + Entries.Length * 

           (Entries.Length > 0 ? Entries[0].Size : 0)); } 

       }

     }

     private static BinaryWriter binaryWriter = 

       new BinaryWriter(new MemoryStream());

     public static Icon Create(byte[] colors, int width, int height, 

       PixelFormat format) {

       if (format != PixelFormat.Format32bppArgb)

         throw new NotImplementedException();

       ICONIMAGE image = new ICONIMAGE(width, height, colors);

       ICONDIR dir = new ICONDIR(

         new ICONDIRENTRY[] { new ICONDIRENTRY(image, 0) } );

       dir.Entries[0].ImageOffset = dir.Size;

       Icon icon;

       binaryWriter.BaseStream.Position = 0;

 			dir.Write(binaryWriter);

       image.Write(binaryWriter);

 			binaryWriter.BaseStream.Position = 0;

       icon = new Icon(binaryWriter.BaseStream);

       return icon;

     }

   }

 }