using UnityEngine;
using UnityEditor;
using System;
using System.IO;
using System.Linq;
using System.Xml.Linq;

namespace FlashTools.Internal {
	public class FlashAnimPostprocessor : AssetPostprocessor {
		static void OnPostprocessAllAssets(
			string[] imported_assets, string[] deleted_assets,
			string[] moved_assets, string[] moved_from_asset_paths)
		{
			var fta_assets = imported_assets
				.Where(p => Path.GetExtension(p).ToLower().Equals(".fta"));
			foreach ( var fta_asset in fta_assets ) {
				FtaAssetProcess(fta_asset);
			}
		}

		static void FtaAssetProcess(string fta_asset) {
			var flash_anim_data = LoadFlashAnimFromFtaFile(fta_asset);
			if ( flash_anim_data != null ) {
				var new_asset_path = Path.ChangeExtension(fta_asset, ".asset");
				var new_asset = AssetDatabase.LoadAssetAtPath<FlashAnimAsset>(new_asset_path);
				if ( !new_asset ) {
					new_asset = ScriptableObject.CreateInstance<FlashAnimAsset>();
					AssetDatabase.CreateAsset(new_asset, new_asset_path);
				}
				new_asset.Data = flash_anim_data;
				EditorUtility.SetDirty(new_asset);
				AssetDatabase.SaveAssets();
			}
		}

		static FlashAnimData LoadFlashAnimFromFtaFile(string fta_path) {
			try {
				var fta_root_elem = XDocument.Load(fta_path).Document.Root;
				var flash_anim_data = new FlashAnimData();
				LoadFlashAnimStageFromFtaRootElem  (fta_root_elem, flash_anim_data);
				LoadFlashAnimLibraryFromFtaRootElem(fta_root_elem, flash_anim_data);
				LoadFlashAnimStringsFromFtaRootElem(fta_root_elem, flash_anim_data);
				return flash_anim_data;
			} catch ( Exception e ) {
				Debug.LogErrorFormat("Parsing FTA file error: {0}", e.Message);
				return null;
			}
		}

		// -----------------------------
		// Stage
		// -----------------------------

		static void LoadFlashAnimStageFromFtaRootElem(XElement root_elem, FlashAnimData data) {
			var stage_elem = root_elem.Element("stage");
			LoadFlashAnimLayersFromFtaSymbolElem(stage_elem, data.Stage);
		}

		// -----------------------------
		// Library
		// -----------------------------

		static void LoadFlashAnimLibraryFromFtaRootElem(XElement root_elem, FlashAnimData data) {
			var library_elem = root_elem.Element("library");
			LoadFlashAnimBitmapsFromFtaLibraryElem(library_elem, data);
			LoadFlashAnimSymbolsFromFtaLibraryElem(library_elem, data);
		}

		static void LoadFlashAnimBitmapsFromFtaLibraryElem(XElement library_elem, FlashAnimData data) {
			foreach ( var bitmap_elem in library_elem.Elements("bitmap") ) {
				var bitmap = new FlashAnimBitmapData();
				bitmap.Id = SafeLoadStrFromElemAttr(bitmap_elem, "id", bitmap.Id);
				if ( string.IsNullOrEmpty(bitmap.Id) ) {
					throw new UnityException("bitmap id not found");
				}
				bitmap.ImageSource = bitmap.Id + ".png";
				// TODO: add image importer check
				data.Library.Bitmaps.Add(bitmap);
			}
		}

		static void LoadFlashAnimSymbolsFromFtaLibraryElem(XElement library_elem, FlashAnimData data) {
			foreach ( var symbol_elem in library_elem.Elements("symbol") ) {
				var symbol = new FlashAnimSymbolData();
				symbol.Id = SafeLoadStrFromElemAttr(symbol_elem, "id", symbol.Id);
				if ( string.IsNullOrEmpty(symbol.Id) ) {
					throw new UnityException("symbol id not found");
				}
				LoadFlashAnimLayersFromFtaSymbolElem(symbol_elem, symbol);
				data.Library.Symbols.Add(symbol);
			}
		}

		static void LoadFlashAnimLayersFromFtaSymbolElem(XElement symbol_elem, FlashAnimSymbolData data) {
			foreach ( var layer_elem in symbol_elem.Elements("layer") ) {
				var layer = new FlashAnimLayerData();
				layer.Id        = SafeLoadStrFromElemAttr (layer_elem, "id"        , layer.Id);
				layer.Visible   = SafeLoadBoolFromElemAttr(layer_elem, "visible"   , layer.Visible);
				layer.LayerType = SafeLoadEnumFromElemAttr(layer_elem, "layer_type", FlashAnimLayerType.Normal);
				LoadFlashAnimFramesFromFtaLayerElem(layer_elem, layer);
				data.Layers.Add(layer);
			}
		}

		static void LoadFlashAnimFramesFromFtaLayerElem(XElement layer_elem, FlashAnimLayerData data) {
			foreach ( var frame_elem in layer_elem.Elements("frame") ) {
				var frame = new FlashAnimFrameData();
				frame.Id        = SafeLoadStrFromElemAttr(frame_elem, "id"        , frame.Id);
				frame.Index     = SafeLoadIntFromElemAttr(frame_elem, "index"     , frame.Index);
				frame.Duration  = SafeLoadIntFromElemAttr(frame_elem, "duration"  , frame.Duration);
				LoadFlashAnimElemsFromFtaFrameElem(frame_elem, frame);
				data.Frames.Add(frame);
			}
		}

		static void LoadFlashAnimElemsFromFtaFrameElem(XElement frame_elem, FlashAnimFrameData data) {
			foreach ( var elem_elem in frame_elem.Elements("element") ) {
				var elem = new FlashAnimElemData();
				elem.Id     = SafeLoadStrFromElemAttr(elem_elem, "id"    , elem.Id);
				elem.Depth  = SafeLoadIntFromElemAttr(elem_elem, "depth" , elem.Depth);
				elem.Matrix = SafeLoadMatFromElemAttr(elem_elem, "matrix", elem.Matrix);
				LoadFlashAnimInstsFromFtaElemElem(elem_elem, elem);
				data.Elems.Add(elem);
			}
		}

		static void LoadFlashAnimInstsFromFtaElemElem(XElement elem_elem, FlashAnimElemData data) {
			foreach ( var inst_elem in elem_elem.Elements("instance") ) {
				var inst = new FlashAnimInstData();
				inst.Type       = SafeLoadEnumFromElemAttr(inst_elem, "type"       , inst.Type);
				inst.SymbolType = SafeLoadEnumFromElemAttr(inst_elem, "symbol_type", inst.SymbolType);
				inst.BlendMode  = SafeLoadEnumFromElemAttr(inst_elem, "blend_mode" , inst.BlendMode);
				inst.Asset      = SafeLoadStrFromElemAttr (inst_elem, "asset"      , inst.Asset);
				inst.Visible    = SafeLoadBoolFromElemAttr(inst_elem, "visible"    , inst.Visible);
				data.Insts.Add(inst);
			}
		}

		// -----------------------------
		// Strings
		// -----------------------------

		static void LoadFlashAnimStringsFromFtaRootElem(XElement root_elem, FlashAnimData data) {
			var strings_elem = root_elem.Element("strings");
			foreach ( var string_elem in strings_elem.Elements("string") ) {
				var string_id  = SafeLoadStrFromElemAttr(string_elem, "id" , null);
				var string_str = SafeLoadStrFromElemAttr(string_elem, "str", null);
				if ( !string.IsNullOrEmpty(string_id) && string_str != null ) {
					data.Strings.Add(string_id);
					data.Strings.Add(string_str);
				}
			}
		}

		// -----------------------------
		// Common
		// -----------------------------

		static string SafeLoadStrFromElemAttr(XElement elem, string attr_name, string def_value) {
			if ( elem != null && elem.Attribute(attr_name) != null ) {
				return elem.Attribute(attr_name).Value;
			}
			return def_value;
		}

		static int SafeLoadIntFromElemAttr(XElement elem, string attr_name, int def_value) {
			int value;
			if ( elem != null && int.TryParse(SafeLoadStrFromElemAttr(elem, attr_name, ""), out value) ) {
				return value;
			}
			return def_value;
		}

		static bool SafeLoadBoolFromElemAttr(XElement elem, string attr_name, bool def_value) {
			bool value;
			if ( elem != null && bool.TryParse(SafeLoadStrFromElemAttr(elem, attr_name, ""), out value) ) {
				return value;
			}
			return def_value;
		}

		static Matrix4x4 SafeLoadMatFromElemAttr(XElement elem, string attr_name, Matrix4x4 def_value) {
			// TODO: implme
			return def_value;
		}

		static T SafeLoadEnumFromElemAttr<T>(XElement elem, string attr_name, T def_value) {
			try {
				return (T)Enum.Parse(typeof(T), SafeLoadStrFromElemAttr(elem, attr_name, ""));
			} catch ( Exception ) {
				return def_value;
			}
		}
	}
}