using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using UnityEditor;
using System.IO;
using System.Text.RegularExpressions;
using System.Text;
using System.Runtime.Serialization.Formatters.Binary;
using System.Xml.Serialization;

namespace MuHuaEditor {
	public class AssetCollector {
		public static readonly string exportXMLPath = "referencemap.xml";

		public List<string> deleteFileList = new List<string>();
		List<CollectionData> referenceCollection = new List<CollectionData>();

		public bool useCodeStrip = true;
		public bool saveEditorExtensions = true;

		public void Collection(string[] collectionFolders) {
			try {

				XmlSerializer serialize = new XmlSerializer(typeof(List<CollectionData>));

				deleteFileList.Clear();
				referenceCollection.Clear();

				if (File.Exists(exportXMLPath)) {
					using (StreamReader fileStream = new StreamReader(exportXMLPath)) {
						referenceCollection = (List<CollectionData>)serialize.Deserialize(fileStream);
						fileStream.Close();
					}
				}

				List<IReferenceCollection> collectionList = new List<IReferenceCollection>();

				if (useCodeStrip) {
					collectionList.Add(new ClassReferenceCollection(saveEditorExtensions));
				}

				collectionList.AddRange(new IReferenceCollection[] {
					new ShaderReferenceCollection (),
					new AssetReferenceCollection (),
				});

				foreach (IReferenceCollection collection in collectionList) {
					collection.Init(referenceCollection);
					collection.CollectionFiles();
				}

				// Find assets
				var files = StripTargetPathsAll(useCodeStrip, collectionFolders);

				foreach (var path in files) {
					var guid = AssetDatabase.AssetPathToGUID(path);
					deleteFileList.Add(guid);
				}
				EditorUtility.DisplayProgressBar("checking", "collection all files", 0.2f);
				UnregistReferenceFromResources();

				EditorUtility.DisplayProgressBar("checking", "check reference from resources", 0.4f);
				UnregistReferenceFromScenes();

				EditorUtility.DisplayProgressBar("checking", "check reference from scenes", 0.6f);
				if (saveEditorExtensions) {
					UnregistEditorCodes();
				}

				EditorUtility.DisplayProgressBar("checking", "check reference from ignorelist", 0.8f);
				UnregistReferenceFromIgnoreList();
				UnregistReferenceFromExtensionMethod();

				using (var fileStream = new StreamWriter(exportXMLPath)) {
					serialize.Serialize(fileStream, referenceCollection);
					fileStream.Close();
				}

			}
			finally {
				EditorUtility.ClearProgressBar();
			}
		}

		List<string> StripTargetPathsAll(bool isUseCodeStrip, string[] pathes) {
			var files = pathes.SelectMany(c => Directory.GetFiles(c, "*.*", SearchOption.AllDirectories))
					.Distinct()
					.Where(item => Path.GetExtension(item) != ".meta")
					.Where(item => Path.GetExtension(item) != ".js")
					.Where(item => Path.GetExtension(item) != ".dll")
					.Where(item => Regex.IsMatch(item, "[\\/\\\\]Gizmos[\\/\\\\]") == false)
					.Where(item => Regex.IsMatch(item, "[\\/\\\\]Plugins[\\/\\\\]Android[\\/\\\\]") == false)
					.Where(item => Regex.IsMatch(item, "[\\/\\\\]Plugins[\\/\\\\]iOS[\\/\\\\]") == false)
					.Where(item => Regex.IsMatch(item, "[\\/\\\\]Resources[\\/\\\\]") == false);

			if (isUseCodeStrip == false) {
				files = files.Where(item => Path.GetExtension(item) != ".cs");
			}

			return files.ToList();
		}

		void UnregistReferenceFromIgnoreList() {
			var codePaths = deleteFileList.Where(fileName => Path.GetExtension(fileName) == ".cs");

			foreach (var path in codePaths) {
				var code = ClassReferenceCollection.StripComment(File.ReadAllText(path));
				if (Regex.IsMatch(code, "static\\s*(partial)*\\s*class")) {
					UnregistFromDelteList(AssetDatabase.AssetPathToGUID(path));
					continue;
				}
			}
		}

		void UnregistReferenceFromExtensionMethod() {
			var resourcesFiles = deleteFileList
				.Where(item => Path.GetExtension(item) != ".meta")
				.ToArray();
			foreach (var path in AssetDatabase.GetDependencies(resourcesFiles)) {
				UnregistFromDelteList(AssetDatabase.AssetPathToGUID(path));
			}
		}

		void UnregistReferenceFromResources() {
			var resourcesFiles = deleteFileList
				.Where(item => Regex.IsMatch(item, "[\\/\\\\]Resources[\\/\\\\]") == true)
				.Where(item => Path.GetExtension(item) != ".meta")
				.ToArray();
			foreach (var path in AssetDatabase.GetDependencies(resourcesFiles)) {

				UnregistFromDelteList(AssetDatabase.AssetPathToGUID(path));
			}
		}

		void UnregistReferenceFromScenes() {
			// Exclude objects that reference from scenes.
			var scenes = EditorBuildSettings.scenes
				.Where(item => item.enabled == true)
					.Select(item => item.path)
					.ToArray();
			foreach (var path in AssetDatabase.GetDependencies(scenes)) {

				UnregistFromDelteList(AssetDatabase.AssetPathToGUID(path));
			}
		}

		void UnregistEditorCodes() {
			// Exclude objects that reference from Editor API
			var editorcodes = Directory.GetFiles("Assets", "*.*", SearchOption.AllDirectories)
				.Where(fileName => Path.GetExtension(fileName) == ".cs")
				.Where(item => Regex.IsMatch(item, "[\\/\\\\]Editor[\\/\\\\]") == true)
				.ToArray();

			EditorUtility.DisplayProgressBar("checking", "check reference from editor codes", 0.8f);

			foreach (var path in editorcodes) {
				var code = ClassReferenceCollection.StripComment(File.ReadAllText(path));
				if (Regex.IsMatch(code, "(\\[MenuItem|AssetPostprocessor|EditorWindow)")) {
					UnregistFromDelteList(AssetDatabase.AssetPathToGUID(path));
					continue;
				}
			}
			foreach (var path in editorcodes) {
				var guid = AssetDatabase.AssetPathToGUID(path);

				if (referenceCollection.Exists(c => c.fileGuid == guid) == false) {
					continue;
				}

				var referenceGuids = referenceCollection.First(c => c.fileGuid == guid).referenceGids;



				if (referenceGuids.Any(c => deleteFileList.Contains(c) == true) == false) {
					UnregistFromDelteList(AssetDatabase.AssetPathToGUID(path));
				}
			}
		}

		void UnregistFromDelteList(string guid) {
			if (deleteFileList.Contains(guid) == false) {
				return;
			}
			deleteFileList.Remove(guid);

			if (referenceCollection.Exists(c => c.fileGuid == guid)) {
				var refInfo = referenceCollection.First(c => c.fileGuid == guid);
				foreach (var referenceGuid in refInfo.referenceGids) {
					UnregistFromDelteList(referenceGuid);
				}
			}

		}
	}
}