// ClassicalSharp copyright 2014-2016 UnknownShadow200 | Licensed under MIT
using System;
using System.IO;
using System.IO.Compression;
using ClassicalSharp.Entities;
using OpenTK;

namespace ClassicalSharp.Map {

	public sealed class MapCwExporter : IMapFormatExporter {

		BinaryWriter writer;
		NbtFile nbt;
		Game game;
		World map;
		
		public void Save(Stream stream, Game game) {
			using (GZipStream wrapper = new GZipStream(stream, CompressionMode.Compress)) {
				writer = new BinaryWriter(wrapper);
				nbt = new NbtFile(writer);
				this.game = game;
				map = game.World;
				
				nbt.Write(NbtTagType.Compound); nbt.Write("ClassicWorld");
				
				nbt.Write(NbtTagType.Int8);
				nbt.Write("FormatVersion"); nbt.WriteInt8(1);
				
				nbt.Write(NbtTagType.Int8Array);
				nbt.Write("UUID"); nbt.WriteInt32(16);
				nbt.WriteBytes(map.Uuid.ToByteArray());
				
				nbt.Write(NbtTagType.Int16);
				nbt.Write("X"); nbt.WriteInt16((short)map.Width);
				
				nbt.Write(NbtTagType.Int16);
				nbt.Write("Y"); nbt.WriteInt16((short)map.Height);
				
				nbt.Write(NbtTagType.Int16);
				nbt.Write("Z"); nbt.WriteInt16((short)map.Length);
				
				WriteSpawnCompoundTag();
				
				nbt.Write(NbtTagType.Int8Array);
				nbt.Write("BlockArray"); nbt.WriteInt32(map.blocks.Length);
				nbt.WriteBytes(map.blocks);
				
				WriteMetadata();
				
				nbt.Write(NbtTagType.End);
			}
		}
		
		void WriteSpawnCompoundTag() {
			nbt.Write(NbtTagType.Compound); nbt.Write("Spawn");
			LocalPlayer p = game.LocalPlayer;
			Vector3 spawn = p.Position; // TODO: Maybe also keep real spawn too?
			
			nbt.Write(NbtTagType.Int16);
			nbt.Write("X"); nbt.WriteInt16((short)spawn.X);
			
			nbt.Write(NbtTagType.Int16);
			nbt.Write("Y"); nbt.WriteInt16((short)spawn.Y);
			
			nbt.Write(NbtTagType.Int16);
			nbt.Write("Z"); nbt.WriteInt16((short)spawn.Z);
			
			nbt.Write(NbtTagType.Int8);
			nbt.Write("H");
			nbt.WriteUInt8((byte)Utils.DegreesToPacked(p.SpawnYaw));
			
			nbt.Write(NbtTagType.Int8);
			nbt.Write("P");
			nbt.WriteUInt8((byte)Utils.DegreesToPacked(p.SpawnPitch));
			
			nbt.Write(NbtTagType.End);
		}
		
		void WriteMetadata() {
			nbt.Write(NbtTagType.Compound); nbt.Write("Metadata");
			nbt.Write(NbtTagType.Compound); nbt.Write("CPE");
			LocalPlayer p = game.LocalPlayer;

			nbt.WriteCpeExtCompound("ClickDistance", 1);
			nbt.Write(NbtTagType.Int16);
			nbt.Write("Distance"); nbt.WriteInt16((short)(p.ReachDistance * 32));
			nbt.Write(NbtTagType.End);
			
			nbt.WriteCpeExtCompound("EnvWeatherType", 1);
			nbt.Write(NbtTagType.Int8);
			nbt.Write("WeatherType"); nbt.WriteUInt8((byte)map.Env.Weather);
			nbt.Write(NbtTagType.End);
			
			nbt.WriteCpeExtCompound("EnvMapAppearance", 1);
			nbt.Write(NbtTagType.Int8);
			nbt.Write("SideBlock"); nbt.WriteUInt8(map.Env.SidesBlock);
			nbt.Write(NbtTagType.Int8);
			nbt.Write("EdgeBlock"); nbt.WriteUInt8(map.Env.EdgeBlock);
			nbt.Write(NbtTagType.Int16);
			nbt.Write("SideLevel"); nbt.WriteInt16((short)map.Env.EdgeHeight);
			nbt.Write(NbtTagType.String);
			string url = game.World.TextureUrl == null ? "" : game.World.TextureUrl;
			nbt.Write("TextureURL"); nbt.Write(url);
			nbt.Write(NbtTagType.End);
			
			nbt.WriteCpeExtCompound("EnvColors", 1);
			WriteColourCompound("Sky", map.Env.SkyCol);
			WriteColourCompound("Cloud", map.Env.CloudsCol);
			WriteColourCompound("Fog", map.Env.FogCol);
			WriteColourCompound("Ambient", map.Env.Shadowlight);
			WriteColourCompound("Sunlight", map.Env.Sunlight);
			nbt.Write(NbtTagType.End);
			
			nbt.WriteCpeExtCompound("BlockDefinitions", 1);
			uint[] flags = game.BlockInfo.DefinedCustomBlocks;
			for (int block = 1; block < 256; block++) {
				if ((flags[block >> 5] & (1u << (block & 0x1F))) != 0)
					WriteBlockDefinitionCompound((byte)block);
			}
			nbt.Write(NbtTagType.End);
			
			nbt.Write(NbtTagType.End);
			nbt.Write(NbtTagType.End);
		}
		
		void WriteColourCompound(string name, FastColour col) {
			nbt.Write(NbtTagType.Compound); nbt.Write(name);
			
			nbt.Write(NbtTagType.Int16);
			nbt.Write("R"); nbt.WriteInt16(col.R);
			nbt.Write(NbtTagType.Int16);
			nbt.Write("G"); nbt.WriteInt16(col.G);
			nbt.Write(NbtTagType.Int16);
			nbt.Write("B"); nbt.WriteInt16(col.B);
			
			nbt.Write(NbtTagType.End);
		}
		
		unsafe void WriteBlockDefinitionCompound(byte id) {
			BlockInfo info = game.BlockInfo;
			nbt.Write(NbtTagType.Compound); nbt.Write("Block" + id);
			
			nbt.Write(NbtTagType.Int8);
			nbt.Write("ID"); nbt.WriteUInt8(id);
			nbt.Write(NbtTagType.String);
			nbt.Write("Name"); nbt.Write(info.Name[id]);
			nbt.Write(NbtTagType.Int8);
			nbt.Write("CollideType"); nbt.WriteUInt8((byte)info.Collide[id]);		
			float speed = info.SpeedMultiplier[id];
			nbt.Write(NbtTagType.Real32);
			nbt.Write("Speed"); nbt.WriteInt32(*((int*)&speed));
			
			nbt.Write(NbtTagType.Int8Array);
			nbt.Write("Textures"); nbt.WriteInt32(6);
			nbt.WriteUInt8(info.GetTextureLoc(id, Side.Top));
			nbt.WriteUInt8(info.GetTextureLoc(id, Side.Bottom));
			nbt.WriteUInt8(info.GetTextureLoc(id, Side.Left));
			nbt.WriteUInt8(info.GetTextureLoc(id, Side.Right));
			nbt.WriteUInt8(info.GetTextureLoc(id, Side.Front));
			nbt.WriteUInt8(info.GetTextureLoc(id, Side.Back));
			
			nbt.Write(NbtTagType.Int8);
			nbt.Write("TransmitsLight"); nbt.WriteUInt8(info.BlocksLight[id] ? 0 : 1);
			nbt.Write(NbtTagType.Int8);
			nbt.Write("WalkSound"); nbt.WriteUInt8((byte)info.DigSounds[id]);
			nbt.Write(NbtTagType.Int8);
			nbt.Write("FullBright"); nbt.WriteUInt8(info.FullBright[id] ? 1 : 0);
			nbt.Write(NbtTagType.Int8);
			nbt.Write("Shape"); nbt.WriteUInt8(GetShape(info, id));
			nbt.Write(NbtTagType.Int8);
			nbt.Write("BlockDraw"); nbt.WriteUInt8(GetDraw(info, id));
			
			FastColour col = info.FogColour[id];
			nbt.Write(NbtTagType.Int8Array);
			nbt.Write("Fog"); nbt.WriteInt32(4);
			byte fog = (byte)(128 * info.FogDensity[id] - 1);
			nbt.WriteUInt8(info.FogDensity[id] == 0 ? (byte)0 : fog);
			nbt.WriteUInt8(col.R); nbt.WriteUInt8(col.G); nbt.WriteUInt8(col.B);
			
			Vector3 min = info.MinBB[id], max = info.MaxBB[id];
			nbt.Write(NbtTagType.Int8Array);
			nbt.Write("Coords"); nbt.WriteInt32(6);
			nbt.WriteUInt8((byte)(min.X * 16)); nbt.WriteUInt8((byte)(min.Y * 16)); 
			nbt.WriteUInt8((byte)(min.Z * 16)); nbt.WriteUInt8((byte)(max.X * 16));
			nbt.WriteUInt8((byte)(max.Y * 16)); nbt.WriteUInt8((byte)(max.Z * 16));
			nbt.Write(NbtTagType.End);
		}
		
		int GetShape(BlockInfo info, byte id) {
			return info.Draw[id] == DrawType.Sprite ? 0 : (int)(info.MaxBB[id].Y * 16);
		}
		
		int GetDraw(BlockInfo info, byte id) {
			if (info.Draw[id] == DrawType.Sprite) 
				return DrawType.Transparent;
			return info.Draw[id];
		}
	}
}