using System;
using System.IO;
using System.Globalization;
using SlimDX;
using CodeImp.DoomBuilder.GZBuilder.Data;
using CodeImp.DoomBuilder.Geometry;

namespace CodeImp.DoomBuilder.GZBuilder.GZDoom {
	internal sealed class ModeldefStructure {
		private const int MAX_MODELS = 4; //maximum models per modeldef entry, zero-based

		internal ModelData Parse(ModeldefParser parser) {
			string[] textureNames = new string[4];
			string[] modelNames = new string[4];
			string path = "";
			Vector3 scale = new Vector3(1, 1, 1);
			float zOffset = 0;
			float angleOffset = 0;
			float pitchOffset = 0;
			float rollOffset = 0;

			string token;
			bool gotErrors = false;

			//read modeldef structure contents
			while (parser.SkipWhitespace(true)) {
				token = parser.ReadToken();

				if (!string.IsNullOrEmpty(token)) {
					token = parser.StripTokenQuotes(token).ToLowerInvariant(); //ANYTHING can be quoted...
//path
					if (token == "path") {
						parser.SkipWhitespace(true);
						path = parser.StripTokenQuotes(parser.ReadToken()).Replace("/", "\\");

						if (string.IsNullOrEmpty(path)) {
							General.ErrorLogger.Add(ErrorType.Error, "Error in " + parser.Source + " at line " + parser.GetCurrentLineNumber() + ": expected path to model, but got '" + token + "'");
							gotErrors = true;
							break;
						}
//model
					} else if (token == "model") {
						parser.SkipWhitespace(true);

						//model index
						int modelIndex;
						token = parser.StripTokenQuotes(parser.ReadToken());
						if (!int.TryParse(token, NumberStyles.Integer, CultureInfo.InvariantCulture, out modelIndex)) {
							// Not numeric!
							General.ErrorLogger.Add(ErrorType.Error, "Error in " + parser.Source + " at line " + parser.GetCurrentLineNumber() + ": expected model index, but got '" + token + "'");
							gotErrors = true;
							break;
						}

						if (modelIndex >= MAX_MODELS) {
							General.ErrorLogger.Add(ErrorType.Error, "Error in " + parser.Source + " at line " + parser.GetCurrentLineNumber() + ": GZDoom doesn't allow more than " + MAX_MODELS + " per MODELDEF entry!");
							break;
						}

						parser.SkipWhitespace(true);

						//model path
						token = parser.StripTokenQuotes(parser.ReadToken()).ToLowerInvariant();
						if (string.IsNullOrEmpty(token)) {
							General.ErrorLogger.Add(ErrorType.Error, "Error in " + parser.Source + " at line " + parser.GetCurrentLineNumber() + ": expected model name, but got '" + token + "'");
							gotErrors = true;
							break;
						} else {
							//check extension
							string fileExt = Path.GetExtension(token);
							if (string.IsNullOrEmpty(fileExt)){
								General.ErrorLogger.Add(ErrorType.Error, "Error in " + parser.Source + " at line " + parser.GetCurrentLineNumber() + ": model '" + token + "' won't be loaded. Models without extension are not supported by GZDoom.");
								gotErrors = true;
								break;
							}
							if(fileExt != ".md3" && fileExt != ".md2") {
								General.ErrorLogger.Add(ErrorType.Error, "Error in " + parser.Source + " at line " + parser.GetCurrentLineNumber() + ": model '" + token + "' won't be loaded. Only MD2 and MD3 models are supported.");
								gotErrors = true;
								break;
							}

							//GZDoom allows models with identical modelIndex, it uses the last one encountered
							modelNames[modelIndex] = Path.Combine(path, token);
						}
//skin
					} else if (token == "skin") {
						parser.SkipWhitespace(true);

						//skin index
						int skinIndex;
						token = parser.StripTokenQuotes(parser.ReadToken());
						if (!int.TryParse(token, NumberStyles.Integer, CultureInfo.InvariantCulture, out skinIndex)) {
							// Not numeric!
							General.ErrorLogger.Add(ErrorType.Error, "Error in " + parser.Source + " at line " + parser.GetCurrentLineNumber() + ": expected skin index, but got '" + token + "'");
							gotErrors = true;
							break;
						}

						if (skinIndex >= MAX_MODELS) {
							General.ErrorLogger.Add(ErrorType.Error, "Error in " + parser.Source + " at line " + parser.GetCurrentLineNumber() + ": GZDoom doesn't allow more than " + MAX_MODELS + " per MODELDEF entry!");
							break;
						}

						parser.SkipWhitespace(true);

						//skin path
						token = parser.StripTokenQuotes(parser.ReadToken()).ToLowerInvariant();
						if (string.IsNullOrEmpty(token)) {
							General.ErrorLogger.Add(ErrorType.Error, "Error in " + parser.Source + " at line " + parser.GetCurrentLineNumber() + ": expected skin name, but got '" + token + "'");
							gotErrors = true;
							break;
						} else {
							//check extension
							string ext = Path.GetExtension(token);
							if(Array.IndexOf(TextureData.SUPPORTED_TEXTURE_EXTENSIONS, ext) == -1) {
								General.ErrorLogger.Add(ErrorType.Error, "Error in " + parser.Source + " at line " + parser.GetCurrentLineNumber() + ": image format '" + ext + "' is not supported!");
								textureNames[skinIndex] = TextureData.INVALID_TEXTURE;
							} else {
								//GZDoom allows skins with identical modelIndex, it uses the last one encountered
								textureNames[skinIndex] = Path.Combine(path, token);
							}
						}
//scale
					} else if (token == "scale") {
						parser.SkipWhitespace(true);

						token = parser.StripTokenQuotes(parser.ReadToken());
						if (!parser.ReadSignedFloat(token, ref scale.X)) {
							// Not numeric!
							General.ErrorLogger.Add(ErrorType.Error, "Error in " + parser.Source + " at line " + parser.GetCurrentLineNumber() + ": expected scale X value, but got '" + token + "'");
							gotErrors = true;
							break;
						}

						parser.SkipWhitespace(true);

						token = parser.StripTokenQuotes(parser.ReadToken());
						if (!parser.ReadSignedFloat(token, ref scale.Y)) {
							// Not numeric!
							General.ErrorLogger.Add(ErrorType.Error, "Error in " + parser.Source + " at line " + parser.GetCurrentLineNumber() + ": expected scale Y value, but got '" + token + "'");
							gotErrors = true;
							break;
						}

						parser.SkipWhitespace(true);

						token = parser.StripTokenQuotes(parser.ReadToken());
						if (!parser.ReadSignedFloat(token, ref scale.Z)) {
							// Not numeric!
							General.ErrorLogger.Add(ErrorType.Error, "Error in " + parser.Source + " at line " + parser.GetCurrentLineNumber() + ": expected scale Z value, but got '" + token + "'");
							gotErrors = true;
							break;
						}
//zoffset
					} else if (token == "zoffset") {
						parser.SkipWhitespace(true);

						token = parser.StripTokenQuotes(parser.ReadToken());
						if (!parser.ReadSignedFloat(token, ref zOffset)) {
							// Not numeric!
							General.ErrorLogger.Add(ErrorType.Error, "Error in " + parser.Source + " at line " + parser.GetCurrentLineNumber() + ": expected ZOffset value, but got '" + token + "'");
							gotErrors = true;
							break;
						}
//angleoffset
					} else if (token == "angleoffset") {
						parser.SkipWhitespace(true);

						token = parser.StripTokenQuotes(parser.ReadToken());
						if (!parser.ReadSignedFloat(token, ref angleOffset)) {
							// Not numeric!
							General.ErrorLogger.Add(ErrorType.Error, "Error in " + parser.Source + " at line " + parser.GetCurrentLineNumber() + ": expected AngleOffset value, but got '" + token + "'");
							gotErrors = true;
							break;
						}
//pitchoffset
					} else if (token == "pitchoffset") {
						parser.SkipWhitespace(true);

						token = parser.StripTokenQuotes(parser.ReadToken());
						if (!parser.ReadSignedFloat(token, ref pitchOffset)) {
							// Not numeric!
							General.ErrorLogger.Add(ErrorType.Error, "Error in " + parser.Source + " at line " + parser.GetCurrentLineNumber() + ": expected PitchOffset value, but got '" + token + "'");
							gotErrors = true;
							break;
						}
//rolloffset
					} else if (token == "rolloffset") {
						parser.SkipWhitespace(true);

						token = parser.StripTokenQuotes(parser.ReadToken());
						if (!parser.ReadSignedFloat(token, ref rollOffset)) {
							// Not numeric!
							General.ErrorLogger.Add(ErrorType.Error, "Error in " + parser.Source + " at line " + parser.GetCurrentLineNumber() + ": expected RollOffset value, but got '" + token + "'");
							gotErrors = true;
							break;
						}
//frameindex
					} else if(token == "frameindex" || token == "frame") {
						//parsed all required fields. if got more than one model - find which one(s) should be displayed 
						int len = modelNames.GetLength(0);
						if (!gotErrors && len > 1) {
							string spriteLump = null;
							string spriteFrame = null;
							bool[] modelsUsed = new bool[MAX_MODELS];

							//step back
							parser.DataStream.Seek(-token.Length - 1, SeekOrigin.Current);

							//here we check which models are used in first encountered lump and frame
							while (parser.SkipWhitespace(true)) {
								token = parser.StripTokenQuotes(parser.ReadToken()).ToLowerInvariant();

								if(token == "frameindex" || token == "frame") {
									bool frameIndex = (token == "frameindex");
									parser.SkipWhitespace(true);

									//should be sprite lump
									token = parser.StripTokenQuotes(parser.ReadToken()).ToLowerInvariant();

									if (string.IsNullOrEmpty(spriteLump)) {
										spriteLump = token;
									} else if (spriteLump != token) { //got another lump
										for (int i = 0; i < modelsUsed.Length; i++) {
											if (!modelsUsed[i]) {
												modelNames[i] = null;
												textureNames[i] = null;
											}
										}
										break;
									}

									parser.SkipWhitespace(true);

									//should be sprite frame
									token = parser.StripTokenQuotes(parser.ReadToken()).ToLowerInvariant();

									if (string.IsNullOrEmpty(spriteFrame)) {
										spriteFrame = token;
									} else if (spriteFrame != token) { //got another frame
										for (int i = 0; i < modelsUsed.Length; i++) {
											if (!modelsUsed[i]) {
												modelNames[i] = null;
												textureNames[i] = null;
											}
										}
										break;
									}

									parser.SkipWhitespace(true);

									//should be model index
									token = parser.StripTokenQuotes(parser.ReadToken());

									int modelIndex;
									if (!int.TryParse(token, NumberStyles.Integer, CultureInfo.InvariantCulture, out modelIndex)) {
										// Not numeric!
										General.ErrorLogger.Add(ErrorType.Error, "Error in " + parser.Source + " at line " + parser.GetCurrentLineNumber() + ": expected model index, but got '" + token + "'");
										gotErrors = true;
										break;
									}

									if (modelIndex >= MAX_MODELS) {
										General.ErrorLogger.Add(ErrorType.Error, "Error in " + parser.Source + " at line " + parser.GetCurrentLineNumber() + ": GZDoom doesn't allow more than " + MAX_MODELS + " per MODELDEF entry!");
										gotErrors = true;
										break;
									}

									if (modelNames[modelIndex] == null) {
										General.ErrorLogger.Add(ErrorType.Error, "Error in " + parser.Source + " at line " + parser.GetCurrentLineNumber() + ": got model index, which doesn't correspond to any defined model!");
										gotErrors = true;
										break;
									}

									modelsUsed[modelIndex] = true;

									parser.SkipWhitespace(true);

									//should be frame name or index. Currently I have no use for it
									token = parser.StripTokenQuotes(parser.ReadToken());

									if(frameIndex) {
										int frame;
										if(!int.TryParse(token, NumberStyles.Integer, CultureInfo.InvariantCulture, out frame)) {
											// Not numeric!
											General.ErrorLogger.Add(ErrorType.Error, "Error in " + parser.Source + " at line " + parser.GetCurrentLineNumber() + ": expected model frame, but got '" + token + "'");
											gotErrors = true;
											break;
										}
									}

								} else {
									//must be "}", step back
									parser.DataStream.Seek(-token.Length - 1, SeekOrigin.Current);
									break;
								}
							}
						}
						break;
					}
				}
			}

			//find closing brace, then quit;
			while (parser.SkipWhitespace(true)) {
				token = parser.ReadToken();
				if (token == "}")
					break;
			}

			if (gotErrors) return null;

			//classname is set in ModeldefParser
			ModelData mde = new ModelData();
			mde.Scale = scale;
			mde.zOffset = zOffset;
			mde.AngleOffset = Angle2D.DegToRad(angleOffset);// *(float)Math.PI / 180.0f;
			mde.RollOffset = Angle2D.DegToRad(rollOffset);// *(float)Math.PI / 180.0f;
			mde.PitchOffset = Angle2D.DegToRad(pitchOffset);// *(float)Math.PI / 180.0f;

			for(int i = 0; i < modelNames.Length; i++) {
				if (!string.IsNullOrEmpty(modelNames[i])) {
					mde.TextureNames.Add(string.IsNullOrEmpty(textureNames[i]) ? textureNames[i] : textureNames[i].ToLowerInvariant());
					mde.ModelNames.Add(modelNames[i].ToLowerInvariant());
				}
			}

			return mde;
		}
	}
}