using System;
using System.Collections;
using System.Collections.Generic;

using NW4RTools.Models;

namespace NW4RTools {
	public class BrresReader {
		public static ResFile LoadFile(byte[] data) {
			return new BrresReader().Load(new InputStream(data, ByteEndian.BigEndian));
		}



		private class RawStreamResDict : ResDict<InputStream> {
		}



		private ResFile File;
		private Logger Debug;
		private SortedDictionary<int, string> OffsetMap;

		private BrresReader() {
			Debug = new Logger();
			OffsetMap = new SortedDictionary<int, string>();
		}

		public ResFile Load(InputStream ins) {
			File = new ResFile();

			// Read BRRES header
			byte[] magic = ins.ReadBytes(4);
			UInt16 endian = ins.ReadUInt16();
			UInt16 version = ins.ReadUInt16();
			UInt32 fileSize = ins.ReadUInt32();
			UInt16 headerSize = ins.ReadUInt16();
			UInt16 blockCount = ins.ReadUInt16();

			File.version = version;

			// Read first block header
			byte[] blkMagic = ins.ReadBytes(4);
			UInt32 blkSize = ins.ReadUInt32();

			using (var c = Debug.Push("Root Dictionary")) {
				ReadAndParseDict(ins, ParseRootEntry);
			}


			// DONE!
			using (var c = Debug.Push("Offset Map")) {
				foreach (var e in OffsetMap) {
					Debug.Send("0x{0:X} : {1}", e.Key, e.Value);
				}
			}

			return File;
		}

		private void ParseRootEntry(string name, InputStream ins) {
			using (var c = Debug.Push(name)) {
				switch (name) {
				case "3DModels(NW4R)":
					File.Add(name, ReadAndConvertDict<Model>(ins, ConvertModelResource));
					break;
				default:
					Debug.Send("Not implemented");
					return;
				}
			}
		}

		private Model ConvertModelResource(string name, InputStream ins) {
			using (var c = Debug.Push(name)) {
				Model mdl = new Model();

				int startPos = ins.Position;

				OffsetMap.Add(startPos, "Model: " + name);

				byte[] magic = ins.ReadBytes(4);
				UInt32 size = ins.ReadUInt32();
				UInt32 version = ins.ReadUInt32();

				Debug.Send("Offset: 0x{0:X}; Size: 0x{1:X}; Version: {2}", startPos, size, version);

				Int32 resFileOffset = ins.ReadInt32();
				Int32 bytecodeOffset = ins.ReadInt32();
				Int32 nodeOffset = ins.ReadInt32();
				Int32 vtxPosOffset = ins.ReadInt32();
				Int32 vtxNrmOffset = ins.ReadInt32();
				Int32 vtxClrOffset = ins.ReadInt32();
				Int32 texCoordOffset = ins.ReadInt32();
				Int32 vtxFurVecOffset = ins.ReadInt32();
				Int32 vtxFurPosOffset = ins.ReadInt32();
				Int32 materialOffset = ins.ReadInt32();
				Int32 shaderOffset = ins.ReadInt32();
				Int32 shapeOffset = ins.ReadInt32();
				Int32 textureOffset = ins.ReadInt32();
				Int32 paletteOffset = ins.ReadInt32();
				Int32 unkOffset = ins.ReadInt32();
				Int32 nameOffset = ins.ReadInt32();

				int infoStructPos = ins.Position;
				OffsetMap.Add(infoStructPos, "Model Info Struct for: " + name);
				UInt32 infoSize = ins.ReadUInt32();
				// should be 0x40

				Int32 mdlOffset = ins.ReadInt32();
				mdl.ScaleMode = (Model.ScaleModeType)ins.ReadUInt32();
				mdl.TexMatrixMode = (Model.TexMatrixModeType)ins.ReadUInt32();
				UInt32 vtxCount = ins.ReadUInt32();
				UInt32 triCount = ins.ReadUInt32();
				UInt32 unk = ins.ReadUInt32();
				UInt32 nodeCount = ins.ReadUInt32();
				mdl.UsesNrmMtxArray = (bool)(ins.ReadByte() != 0);
				mdl.UsesTexMtxArray = (bool)(ins.ReadByte() != 0);
				ins.Skip(2);
				Int32 mtxDataOffset = ins.ReadInt32();
				mdl.Minimum = ins.ReadVec3();
				mdl.Maximum = ins.ReadVec3();


				ins.Seek(infoStructPos + mtxDataOffset);
				UInt32 mtxDataCount = ins.ReadUInt32();
				mdl.MatrixIDtoNodeID = new int[mtxDataCount];

				for (int i = 0; i < mtxDataCount; i++) {
					mdl.MatrixIDtoNodeID[i] = ins.ReadInt32();
				}



				// Load bytecode
				using (var c2 = Debug.Push("Bytecode"))
					mdl.Bytecode = ReadAndConvertDict<ByteCode>(ins.At(startPos + bytecodeOffset), ConvertModelBytecode);

				// Load nodes and fix up pointers
				StartNodeLoading();

				using (var c2 = Debug.Push("Nodes"))
					mdl.Nodes = ReadAndConvertDict<Node>(ins.At(startPos + nodeOffset), ConvertModelNode);

				FinishNodeLoading();

				// Load vertex data
				using (var c2 = Debug.Push("Vertex Position Data"))
					mdl.VtxPosData = ReadAndConvertDict<VertexPosData>(ins.At(startPos + vtxPosOffset), ConvertVtxPosData);
				using (var c2 = Debug.Push("Vertex Normal Data"))
					mdl.VtxNrmData = ReadAndConvertDict<VertexNrmData>(ins.At(startPos + vtxNrmOffset), ConvertVtxNrmData);
				using (var c2 = Debug.Push("Vertex Colour Data"))
					mdl.VtxClrData = ReadAndConvertDict<VertexClrData>(ins.At(startPos + vtxClrOffset), ConvertVtxClrData);
				using (var c2 = Debug.Push("Vertex TexCoord Data"))
					mdl.VtxTexCoordData = ReadAndConvertDict<VertexTexCoordData>(ins.At(startPos + texCoordOffset), ConvertVtxTexCoordData);

				return mdl;
			}
		}

		private Models.ByteCode ConvertModelBytecode(string name, InputStream ins) {
			var bc = new Models.ByteCode();
			
			OffsetMap.Add(ins.Position, "ByteCode: " + name);

			while (true) {
				ByteCode.OpType op = (ByteCode.OpType)ins.ReadByte();

				switch (op) {
				case ByteCode.OpType.Done:
					bc.Instructions.Add(new ByteCode.DoneInstruction());
					return bc;

				case ByteCode.OpType.AssignNodeToParentMtx:
					var insn2 = new ByteCode.AssignNodeToParentMtxInstruction();
					insn2.NodeID = ins.ReadUInt16();
					insn2.ParentMatrixID = ins.ReadUInt16();
					bc.Instructions.Add(insn2);
					break;

				case ByteCode.OpType.BlendMatrices:
					var insn3 = new ByteCode.BlendMatricesInstruction();
					insn3.MatrixID = ins.ReadUInt16();
					insn3.BlendedMatrices = new ByteCode.BlendMatricesInstruction.BlendedMatrix[ins.ReadByte()];
					for (int i = 0; i < insn3.BlendedMatrices.Length; i++) {
						insn3.BlendedMatrices[i].MatrixID = ins.ReadUInt16();
						insn3.BlendedMatrices[i].Ratio = ins.ReadFloat();
					}
					bc.Instructions.Add(insn3);
					break;

				case ByteCode.OpType.DrawShape:
					var insn4 = new ByteCode.DrawShapeInstruction();
					insn4.MaterialID = ins.ReadUInt16();
					insn4.ShapeID = ins.ReadUInt16();
					insn4.NodeID = ins.ReadUInt16();
					ins.Skip(1);
					bc.Instructions.Add(insn4);
					break;

				case ByteCode.OpType.AssignMtxToNode:
					var insn5 = new ByteCode.AssignMtxToNodeInstruction();
					insn5.MatrixID = ins.ReadUInt16();
					insn5.NodeID = ins.ReadUInt16();
					bc.Instructions.Add(insn5);
					break;

				default:
					bc.Instructions.Add(new ByteCode.Instruction());
					break;
				}
			}
		}




		private class NodeLoadInfo {
			public Models.Node Node;
			public string Name;
			public int Position;
			public Int32 ParentOffset;
			public Int32 ChildOffset;
			public Int32 NextOffset;
			public Int32 PrevOffset;
		}

		private Dictionary<int, NodeLoadInfo> NodeLoadData;

		private void StartNodeLoading() {
			NodeLoadData = new Dictionary<int, NodeLoadInfo>();
		}

		private Models.Node ConvertModelNode(string name, InputStream ins) {
			var n = new Models.Node();

			OffsetMap.Add(ins.Position, "Node: " + name);

			int startPos = ins.Position;

			UInt32 size = ins.ReadUInt32();
			Int32 mdlOffset = ins.ReadInt32();
			Int32 nameOffset = ins.ReadInt32();

			n.Index = ins.ReadUInt32();
			n.MatrixID = ins.ReadUInt32();
			n.Flags = ins.ReadUInt32();
			n.BillboardMode = (Node.BillboardType)ins.ReadUInt32();
			UInt32 unk = ins.ReadUInt32();
			// might be swapped with bbmode, check asm to confirm

			n.Scale = ins.ReadVec3();
			n.Rotation = ins.ReadVec3();
			n.Translation = ins.ReadVec3();
			n.BoxMin = ins.ReadVec3();
			n.BoxMax = ins.ReadVec3();

			NodeLoadInfo loadInfo = new NodeLoadInfo();
			loadInfo.ParentOffset = ins.ReadInt32();
			loadInfo.ChildOffset = ins.ReadInt32();
			loadInfo.NextOffset = ins.ReadInt32();
			loadInfo.PrevOffset = ins.ReadInt32();
			loadInfo.Position = startPos;
			loadInfo.Node = n;
			loadInfo.Name = ins.At(startPos + nameOffset - 4).ReadName();
			NodeLoadData[startPos] = loadInfo;

			n.NodeMatrix = ins.ReadMatrix();
			n.NodeInvMatrix = ins.ReadMatrix();

			return n;
		}

		private void FinishNodeLoading() {
			foreach (var dictEntry in NodeLoadData) {
				var entry = dictEntry.Value;
				var node = entry.Node;
				
				if (entry.ParentOffset == 0) {
					node.Parent = null;
				} else {
					NodeLoadInfo n = NodeLoadData[entry.Position + entry.ParentOffset];
					node.Parent = n.Node;
					Debug.Send("Set {0}'s parent to {1}", entry.Name, n.Name);
				}

				if (entry.ChildOffset == 0)
					node.FirstChild = null;
				else
					node.FirstChild = NodeLoadData[entry.Position + entry.ChildOffset].Node;

				if (entry.NextOffset == 0)
					node.Next = null;
				else
					node.Next = NodeLoadData[entry.Position + entry.NextOffset].Node;
				
				if (entry.PrevOffset == 0)
					node.Previous = null;
				else
					node.Previous = NodeLoadData[entry.Position + entry.PrevOffset].Node;
			}

			NodeLoadData = null;
		}




		private void LoadVertexDataBase(InputStream ins, Models.VertexDataBase n) {
			UInt32 size = ins.ReadUInt32();

			Int32 mdlOffset = ins.ReadInt32();
			Int32 dataOffset = ins.ReadInt32();
			Int32 nameOffset = ins.ReadInt32();

			n.Index = ins.ReadUInt32();
			n.ComponentCount = ins.ReadUInt32();
			n.ComponentType = ins.ReadUInt32();
			n.Fraction = ins.ReadByte();
			n.EntrySize = ins.ReadByte();
			n.EntryCount = ins.ReadUInt16();

			n.Data = ins.ReadBytes(n.EntrySize * n.EntryCount);
		}

		private Models.VertexPosData ConvertVtxPosData(string name, InputStream ins) {
			var n = new Models.VertexPosData();

			OffsetMap.Add(ins.Position, "VertexPosData: " + name);

			LoadVertexDataBase(ins, n);

			n.Minimum = ins.ReadVec3();
			n.Maximum = ins.ReadVec3();

			return n;
		}

		private Models.VertexNrmData ConvertVtxNrmData(string name, InputStream ins) {
			var n = new Models.VertexNrmData();

			OffsetMap.Add(ins.Position, "VertexNrmData: " + name);

			LoadVertexDataBase(ins, n);

			return n;
		}

		private Models.VertexClrData ConvertVtxClrData(string name, InputStream ins) {
			var n = new Models.VertexClrData();

			OffsetMap.Add(ins.Position, "VertexClrData: " + name);

			LoadVertexDataBase(ins, n);

			return n;
		}

		private Models.VertexTexCoordData ConvertVtxTexCoordData(string name, InputStream ins) {
			var n = new Models.VertexTexCoordData();

			OffsetMap.Add(ins.Position, "VertexTexCoordData: " + name);

			LoadVertexDataBase(ins, n);

			n.Minimum = ins.ReadVec2();
			n.Maximum = ins.ReadVec2();

			return n;
		}




		private RawStreamResDict ReadDict(InputStream ins) {
			RawStreamResDict output = new RawStreamResDict();
			int dictPos = ins.Position;

			UInt32 dataSize = ins.ReadUInt32();
			UInt32 entryCount = ins.ReadUInt32();

			for (int i = 0; i <= entryCount; i++) {
				UInt16 eRef = ins.ReadUInt16();
				UInt16 flag = ins.ReadUInt16();
				UInt16 iLeft = ins.ReadUInt16();
				UInt16 iRight = ins.ReadUInt16();
				Int32 nameOffset = ins.ReadInt32();
				Int32 dataOffset = ins.ReadInt32();

				//Debug.Send("Position: {6:X}, eRef: {0:X}, flag: {1:X}, iLeft: {2:X}, iRight: {3:X}, nameOffset: {4:X}, dataOffset: {5:X}", eRef, flag, iLeft, iRight, nameOffset, dataOffset, ins.Position);

				if (nameOffset != 0 && dataOffset != 0) {
					string name = ins.At(dictPos + nameOffset - 4).ReadName();
					Debug.Send("Entry: {0} at offset 0x{1:X}", name, dictPos + dataOffset);

					InputStream entryStream = ins.At(dictPos + dataOffset);
					output.Add(name, entryStream);
				}
			}

			return output;
		}



		private delegate void ParseResourceDelegate(string name, InputStream ins);
		private delegate TValue ConvertResourceDelegate<TValue>(string name, InputStream ins);

		private void ReadAndParseDict(InputStream ins, ParseResourceDelegate func) {
			ReadAndParseDict(ins, func, "Unnamed");
		}

		private void ReadAndParseDict(InputStream ins, ParseResourceDelegate func, string dictName) {
			int dictPos = ins.Position;
			RawStreamResDict theDict = ReadDict(ins);
			OffsetMap.Add(dictPos, string.Format("ResDict: {0} [Data ends at 0x{1:X}]", dictName, ins.Position));

			foreach (var entry in theDict) {
				func(entry.Key, entry.Value);
			}
		}

		private ResDict<TValue> ReadAndConvertDict<TValue>(InputStream ins, ConvertResourceDelegate<TValue> func) {
			int dictPos = ins.Position;
			RawStreamResDict theDict = ReadDict(ins);
			var outDict = new ResDict<TValue>();

			// Hack to get the type name
			string valueTypeName = outDict.GetType().GetGenericArguments()[0].ToString();

			OffsetMap.Add(dictPos, string.Format("ResDict: {0} [Data ends at 0x{1:X}]", valueTypeName, ins.Position));

			foreach (var entry in theDict) {
				TValue returnedObject = func(entry.Key, entry.Value);
				outDict.Add(entry.Key, returnedObject);
			}

			return outDict;
		}
	}
}