using System;

namespace NW4RTools {
	public struct GXIndexedVertex {
		public int Position;
		public int Normal;

		public int[] Colors;
		public int[] TexCoords;



		public void LoadFrom(InputStream ins, VertexSettings vs) {
			if (vs.PNMatrixIndexExists)
				throw new NotImplementedException();
			if (vs.TexCoordMatrixIndexExists[0])
				throw new NotImplementedException();
			// won't bother with the rest

			switch (vs.PositionDesc) {
			case VertexSettings.DescType.Direct:
				throw new NotImplementedException();
			case VertexSettings.DescType.None:
				throw new NotImplementedException();
			case VertexSettings.DescType.Index8:
				Position = ins.ReadByte();
				if (Position == 0xFF)
					Position = -1;
				break;
			case VertexSettings.DescType.Index16:
				Position = ins.ReadUInt16();
				if (Position == 0xFFFF)
					Position = -1;
				break;
			}

			// not sure how to detect NBT3 yet
			switch (vs.NormalDesc) {
			case VertexSettings.DescType.Direct:
				throw new NotImplementedException();
			case VertexSettings.DescType.None:
				Normal = -1;
				break;
			case VertexSettings.DescType.Index8:
				Normal = ins.ReadByte();
				if (Normal == 0xFF)
					Normal = -1;
				break;
			case VertexSettings.DescType.Index16:
				Normal = ins.ReadUInt16();
				if (Normal == 0xFFFF)
					Normal = -1;
				break;
			}
			
			Colors = new int[2];
			
			for (int i = 0; i < 2; i++) {
				switch (vs.ColorDesc[i]) {
				case VertexSettings.DescType.Direct:
					throw new NotImplementedException();
				case VertexSettings.DescType.None:
					Colors[i] = -1;
					break;
				case VertexSettings.DescType.Index8:
					Colors[i] = ins.ReadByte();
					if (Colors[i] == 0xFF)
						Colors[i] = -1;
					break;
				case VertexSettings.DescType.Index16:
					Colors[i] = ins.ReadUInt16();
					if (Colors[i] == 0xFFFF)
						Colors[i] = -1;
					break;
				}
			}

			TexCoords = new int[8];

			for (int i = 0; i < 8; i++) {
				switch (vs.TexCoordDesc[i]) {
				case VertexSettings.DescType.Direct:
					throw new NotImplementedException();
				case VertexSettings.DescType.None:
					TexCoords[i] = -1;
					break;
				case VertexSettings.DescType.Index8:
					TexCoords[i] = ins.ReadByte();
					if (TexCoords[i] == 0xFF)
						TexCoords[i] = -1;
					break;
				case VertexSettings.DescType.Index16:
					TexCoords[i] = ins.ReadUInt16();
					if (TexCoords[i] == 0xFFFF)
						TexCoords[i] = -1;
					break;
				}
			}
		}
	}



	public class VertexSettings {
		public enum DescType {
			None,
			Direct,
			Index8,
			Index16
		}

		public enum CompCount {
			Position2 = 0,
			Position3 = 1,
			Normal3 = 0,
			NBT = 1,
			NBT3 = 2,
			Color3 = 0,
			Color4 = 1,
			TexCoord1 = 0,
			TexCoord2 = 1
		}

		public enum CompType {
			UInt8 = 0,
			Int8 = 1,
			UInt16 = 2,
			Int16 = 3,
			Float32 = 4
		}


		public bool PNMatrixIndexExists;
		public bool[] TexCoordMatrixIndexExists;
		public DescType PositionDesc, NormalDesc;
		public DescType[] ColorDesc, TexCoordDesc;

		public CompCount PositionCount, NormalCount;
		public CompCount[] ColorCount, TexCoordCount;

		public CompType PositionFormat, NormalFormat;
		public CompType[] ColorFormat, TexCoordFormat;

		public byte PositionFrac;
		public byte[] TexCoordFrac;



		public VertexSettings() {
			TexCoordMatrixIndexExists = new bool[8];

			ColorDesc = new DescType[2];
			TexCoordDesc = new DescType[8];

			ColorCount = new CompCount[2];
			TexCoordCount = new CompCount[8];

			ColorFormat = new CompType[2];
			TexCoordFormat = new CompType[8];

			TexCoordFrac = new byte[8];
		}


		public void SetDesc(UInt32 val1, UInt32 val2) {
			PNMatrixIndexExists = ((val1 & 1) != 0);

			for (int i = 0; i < 8; i++)
				TexCoordMatrixIndexExists[i] = ((val1 & (2 << i)) != 0);

			PositionDesc = (DescType)((val1 & 0x600) >> 9);
			NormalDesc = (DescType)((val1 & 0x1800) >> 11);
			ColorDesc[0] = (DescType)((val1 & 0x6000) >> 13);
			ColorDesc[1] = (DescType)((val1 & 0x18000) >> 15);

			for (int i = 0; i < 8; i++)
				TexCoordDesc[i] = (DescType)((val2 & (3 << (i * 2))) >> (i * 2));
		}

		public void SetAttrFmt(UInt32 val1, UInt32 val2, UInt32 val3) {
			PositionCount = (CompCount)(val1 & 1);
			PositionFormat = (CompType)((val1 & 0xE) >> 3);
			PositionFrac = (byte)((val1 & 0x1F0) >> 4);

			// note: this field is special
			bool IsNormalSet = ((val1 & 0x200) != 0);
			bool UseNormalIndex3 = ((val1 & 0x80000000) != 0);
			NormalCount = IsNormalSet ? (UseNormalIndex3 ? CompCount.NBT3 : CompCount.NBT) : CompCount.Normal3;
			NormalFormat = (CompType)((val1 & 0x1C00) >> 10);
			
			ColorCount[0] = (CompCount)((val1 & 0x2000) >> 13);
			ColorFormat[0] = (CompType)((val1 & 0x1C000) >> 14);
			
			ColorCount[1] = (CompCount)((val1 & 0x20000) >> 17);
			ColorFormat[1] = (CompType)((val1 & 0x1C0000) >> 18);

			TexCoordCount[0] = (CompCount)((val1 & 0x200000) >> 21);
			TexCoordFormat[0] = (CompType)((val1 & 0x1C00000) >> 22);
			TexCoordFrac[0] = (byte)((val1 & 0x3E000000) >> 25);

			// set in various cases, see libogc gx.c for info
			bool ByteDequant = ((val1 & 0x40000000) != 0);
			
			TexCoordCount[1] = (CompCount)(val2 & 0x1);
			TexCoordFormat[1] = (CompType)((val2 & 0xE) >> 1);
			TexCoordFrac[1] = (byte)((val2 & 0x1F0) >> 4);

			TexCoordCount[2] = (CompCount)((val2 & 0x200) >> 9);
			TexCoordFormat[2] = (CompType)((val2 & 0x1C00) >> 10);
			TexCoordFrac[2] = (byte)((val2 & 0x3E000) >> 13);

			TexCoordCount[3] = (CompCount)((val2 & 0x40000) >> 18);
			TexCoordFormat[3] = (CompType)((val2 & 0x380000) >> 19);
			TexCoordFrac[3] = (byte)((val2 & 0x3E000000) >> 22);

			TexCoordCount[4] = (CompCount)((val2 & 0x8000000) >> 27);
			TexCoordFormat[4] = (CompType)((val2 & 0x70000000) >> 28);
			TexCoordFrac[4] = (byte)(val3 & 0x1F);

			TexCoordCount[5] = (CompCount)((val3 & 0x20) >> 5);
			TexCoordFormat[5] = (CompType)((val3 & 0x1C0) >> 6);
			TexCoordFrac[5] = (byte)((val3 & 0x3E00) >> 9);

			TexCoordCount[6] = (CompCount)((val3 & 0x4000) >> 14);
			TexCoordFormat[6] = (CompType)((val3 & 0x38000) >> 15);
			TexCoordFrac[6] = (byte)((val3 & 0x7C0000) >> 18);

			TexCoordCount[7] = (CompCount)((val3 & 0x800000) >> 23);
			TexCoordFormat[7] = (CompType)((val3 & 0x7000000) >> 24);
			TexCoordFrac[7] = (byte)((val3 & 0xF8000000) >> 27);
		}
	}
}