using System;

namespace NW4RTools.Models {
	public abstract class VertexDataBase {
		public UInt32 Index;

		public VertexSettings.CompCount ComponentCount;
		public VertexSettings.CompType ComponentType;
		public byte Fraction /* Not used for colours */, EntrySize;
		public UInt16 EntryCount;

		// Todo, decode data when reading
		public byte[] RawData;
		public float[][] Data;

		public VertexDataBase() {
		}

		public virtual float[] GetEntry(int index) {
			float[] ret = new float[GetRealCount()];

			float scale = 1.0f / (1 << Fraction);

			InputStream ins = new InputStream(RawData);
			ins.Seek(index * EntrySize);

			for (int i = 0; i < ret.Length; i++) {
				switch (ComponentType) {
				case VertexSettings.CompType.UInt8:
					ret[i] = (float)ins.ReadByte() * scale;
					break;
				case VertexSettings.CompType.Int8:
					ret[i] = (float)ins.ReadSByte() * scale;
					break;
				case VertexSettings.CompType.UInt16:
					ret[i] = (float)ins.ReadUInt16() * scale;
					break;
				case VertexSettings.CompType.Int16:
					ret[i] = (float)ins.ReadInt16() * scale;
					break;
				case VertexSettings.CompType.Float32:
					ret[i] = ins.ReadFloat();
					break;
				default:
					throw new NotImplementedException(String.Format("unimplemented type {0}", (int)ComponentType));
				}
			}

			return ret;
		}

		public void Parse() {
			if (Data != null)
				return;

			Data = new float[EntryCount][];

			for (int i = 0; i < EntryCount; i++) {
				Data[i] = GetEntry(i);
			}
		}


		public abstract int GetRealCount();
	}


	public class VertexPosData : VertexDataBase {
		public Vec3 Minimum, Maximum;

		public VertexPosData() {
		}

		public override int GetRealCount() {
			switch (ComponentCount) {
			case VertexSettings.CompCount.Position2:
				return 2;
			case VertexSettings.CompCount.Position3:
				return 3;
			default:
				return -1;
			}
		}
	}


	public class VertexNrmData : VertexDataBase {
		public VertexNrmData() {
		}

		public override int GetRealCount() {
			switch (ComponentCount) {
			case VertexSettings.CompCount.Normal3:
				return 3;
			default:
				return -1;
			}
		}
	}


	public class VertexClrData : VertexDataBase {
		public VertexClrData() {
		}

		public override int GetRealCount() {
			switch (ComponentCount) {
			case VertexSettings.CompCount.Color3:
				return 3;
			case VertexSettings.CompCount.Color4:
				return 4;
			default:
				return -1;
			}
		}

		public override float[] GetEntry(int index) {
			float[] ret = new float[GetRealCount()];

			InputStream ins = new InputStream(RawData);
			ins.Seek(index * EntrySize);

			byte r, g, b, a;

			// todo: better solution instead of this cast
			switch ((VertexSettings.CompClrType)ComponentType) {
			case VertexSettings.CompClrType.RGB565:
				ushort v565 = ins.ReadUInt16();
				r = (byte)((v565 & 0xF800) >> 8);
				g = (byte)((v565 & 0x07E0) >> 3);
				b = (byte)((v565 & 0x001F) << 3);
				a = 255;
				break;

			case VertexSettings.CompClrType.RGB8:
				r = ins.ReadByte();
				g = ins.ReadByte();
				b = ins.ReadByte();
				a = 255;
				break;

			case VertexSettings.CompClrType.RGBX8:
				r = ins.ReadByte();
				g = ins.ReadByte();
				b = ins.ReadByte();
				a = 255;
				ins.Skip(1);
				break;

			case VertexSettings.CompClrType.RGBA4:
				ushort vA4 = ins.ReadUInt16();
				r = (byte)((vA4 & 0xF000) >> 8);
				g = (byte)((vA4 & 0x0F00) >> 4);
				b = (byte)(vA4 & 0x00F0);
				a = (byte)((vA4 & 0x000F) << 4);
				break;

			case VertexSettings.CompClrType.RGBA6:
				byte v1 = ins.ReadByte();
				byte v2 = ins.ReadByte();
				byte v3 = ins.ReadByte();
				r = (byte)(v1 & 0xF8);
				g = (byte)(((v1 & 7) << 6) | ((v2 & 0xF0) >> 2));
				b = (byte)(((v2 & 0xF) << 4) | ((v3 & 0xC) >> 4));
				a = (byte)((v3 & 0x3F) << 2);
				break;

			case VertexSettings.CompClrType.RGBA8:
				r = ins.ReadByte();
				g = ins.ReadByte();
				b = ins.ReadByte();
				a = ins.ReadByte();
				break;

			default:
				throw new NotImplementedException(String.Format("unimplemented type {0}", (int)ComponentType));
			}

			// this is the easiest way I can think of to handle this atm
			// just use floats for EVERYTHING
			ret[0] = r * (1.0f / 256);
			ret[1] = g * (1.0f / 256);
			ret[2] = b * (1.0f / 256);
			if (ret.Length > 3)
				ret[3] = a * (1.0f / 256);

			return ret;
		}
	}


	public class VertexTexCoordData : VertexDataBase {
		public Vec2 Minimum, Maximum;

		public VertexTexCoordData() {
		}

		public override int GetRealCount() {
			switch (ComponentCount) {
			case VertexSettings.CompCount.TexCoord1:
				return 1;
			case VertexSettings.CompCount.TexCoord2:
				return 2;
			default:
				return -1;
			}
		}
	}
}