using System;
using System.IO;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

namespace YooAsset
{
	internal static class ManifestTools
	{
#if UNITY_EDITOR
		/// <summary>
		/// 序列化（JSON文件）
		/// </summary>
		public static void SerializeToJson(string savePath, PackageManifest manifest)
		{
			string json = JsonUtility.ToJson(manifest, true);
			FileUtility.WriteAllText(savePath, json);
		}

		/// <summary>
		/// 序列化（二进制文件）
		/// </summary>
		public static void SerializeToBinary(string savePath, PackageManifest manifest)
		{
			using (FileStream fs = new FileStream(savePath, FileMode.Create))
			{
				// 创建缓存器
				BufferWriter buffer = new BufferWriter(YooAssetSettings.ManifestFileMaxSize);

				// 写入文件标记
				buffer.WriteUInt32(YooAssetSettings.ManifestFileSign);

				// 写入文件版本
				buffer.WriteUTF8(manifest.FileVersion);

				// 写入文件头信息
				buffer.WriteBool(manifest.EnableAddressable);
				buffer.WriteBool(manifest.LocationToLower);
				buffer.WriteBool(manifest.IncludeAssetGUID);
				buffer.WriteInt32(manifest.OutputNameStyle);
				buffer.WriteUTF8(manifest.PackageName);
				buffer.WriteUTF8(manifest.PackageVersion);

				// 写入资源列表
				buffer.WriteInt32(manifest.AssetList.Count);
				for (int i = 0; i < manifest.AssetList.Count; i++)
				{
					var packageAsset = manifest.AssetList[i];
					buffer.WriteUTF8(packageAsset.Address);
					buffer.WriteUTF8(packageAsset.AssetPath);
					buffer.WriteUTF8(packageAsset.AssetGUID);
					buffer.WriteUTF8Array(packageAsset.AssetTags);
					buffer.WriteInt32(packageAsset.BundleID);
					buffer.WriteInt32Array(packageAsset.DependIDs);
				}

				// 写入资源包列表
				buffer.WriteInt32(manifest.BundleList.Count);
				for (int i = 0; i < manifest.BundleList.Count; i++)
				{
					var packageBundle = manifest.BundleList[i];
					buffer.WriteUTF8(packageBundle.BundleName);
					buffer.WriteUTF8(packageBundle.FileHash);
					buffer.WriteUTF8(packageBundle.FileCRC);
					buffer.WriteInt64(packageBundle.FileSize);
					buffer.WriteBool(packageBundle.IsRawFile);
					buffer.WriteByte(packageBundle.LoadMethod);
					buffer.WriteUTF8Array(packageBundle.Tags);
					buffer.WriteInt32Array(packageBundle.ReferenceIDs);
				}

				// 写入文件流
				buffer.WriteToStream(fs);
				fs.Flush();
			}
		}

		/// <summary>
		/// 反序列化（JSON文件）
		/// </summary>
		public static PackageManifest DeserializeFromJson(string jsonContent)
		{
			return JsonUtility.FromJson<PackageManifest>(jsonContent);
		}

		/// <summary>
		/// 反序列化（二进制文件）
		/// </summary>
		public static PackageManifest DeserializeFromBinary(byte[] binaryData)
		{
			// 创建缓存器
			BufferReader buffer = new BufferReader(binaryData);

			// 读取文件标记
			uint fileSign = buffer.ReadUInt32();
			if (fileSign != YooAssetSettings.ManifestFileSign)
				throw new Exception("Invalid manifest file !");

			// 读取文件版本
			string fileVersion = buffer.ReadUTF8();
			if (fileVersion != YooAssetSettings.ManifestFileVersion)
				throw new Exception($"The manifest file version are not compatible : {fileVersion} != {YooAssetSettings.ManifestFileVersion}");

			PackageManifest manifest = new PackageManifest();
			{
				// 读取文件头信息
				manifest.FileVersion = fileVersion;
				manifest.EnableAddressable = buffer.ReadBool();
				manifest.LocationToLower = buffer.ReadBool();
				manifest.IncludeAssetGUID = buffer.ReadBool();
				manifest.OutputNameStyle = buffer.ReadInt32();
				manifest.PackageName = buffer.ReadUTF8();
				manifest.PackageVersion = buffer.ReadUTF8();

				// 检测配置
				if (manifest.EnableAddressable && manifest.LocationToLower)
					throw new Exception("Addressable not support location to lower !");

				// 读取资源列表
				int packageAssetCount = buffer.ReadInt32();
				manifest.AssetList = new List<PackageAsset>(packageAssetCount);
				for (int i = 0; i < packageAssetCount; i++)
				{
					var packageAsset = new PackageAsset();
					packageAsset.Address = buffer.ReadUTF8();
					packageAsset.AssetPath = buffer.ReadUTF8();
					packageAsset.AssetGUID = buffer.ReadUTF8();
					packageAsset.AssetTags = buffer.ReadUTF8Array();
					packageAsset.BundleID = buffer.ReadInt32();
					packageAsset.DependIDs = buffer.ReadInt32Array();
					manifest.AssetList.Add(packageAsset);
				}

				// 读取资源包列表
				int packageBundleCount = buffer.ReadInt32();
				manifest.BundleList = new List<PackageBundle>(packageBundleCount);
				for (int i = 0; i < packageBundleCount; i++)
				{
					var packageBundle = new PackageBundle();
					packageBundle.BundleName = buffer.ReadUTF8();
					packageBundle.FileHash = buffer.ReadUTF8();
					packageBundle.FileCRC = buffer.ReadUTF8();
					packageBundle.FileSize = buffer.ReadInt64();
					packageBundle.IsRawFile = buffer.ReadBool();
					packageBundle.LoadMethod = buffer.ReadByte();
					packageBundle.Tags = buffer.ReadUTF8Array();
					packageBundle.ReferenceIDs = buffer.ReadInt32Array();
					manifest.BundleList.Add(packageBundle);
				}
			}

			// 填充BundleDic
			manifest.BundleDic = new Dictionary<string, PackageBundle>(manifest.BundleList.Count);
			foreach (var packageBundle in manifest.BundleList)
			{
				packageBundle.ParseBundle(manifest.PackageName, manifest.OutputNameStyle);
				manifest.BundleDic.Add(packageBundle.BundleName, packageBundle);
			}

			// 填充AssetDic
			manifest.AssetDic = new Dictionary<string, PackageAsset>(manifest.AssetList.Count);
			foreach (var packageAsset in manifest.AssetList)
			{
				// 注意：我们不允许原始路径存在重名
				string assetPath = packageAsset.AssetPath;
				if (manifest.AssetDic.ContainsKey(assetPath))
					throw new Exception($"AssetPath have existed : {assetPath}");
				else
					manifest.AssetDic.Add(assetPath, packageAsset);
			}

			return manifest;
		}
#endif

		public static string GetRemoteBundleFileExtension(string bundleName)
		{
			string fileExtension = Path.GetExtension(bundleName);
			return fileExtension;
		}
		public static string GetRemoteBundleFileName(int nameStyle, string bundleName, string fileExtension, string fileHash)
		{
			if (nameStyle == 1) //HashName
			{
				return StringUtility.Format("{0}{1}", fileHash, fileExtension);
			}
			else if (nameStyle == 4) //BundleName_HashName
			{
				string fileName = bundleName.Remove(bundleName.LastIndexOf('.'));
				return StringUtility.Format("{0}_{1}{2}", fileName, fileHash, fileExtension);
			}
			else
			{
				throw new NotImplementedException($"Invalid name style : {nameStyle}");
			}
		}

		/// <summary>
		/// 转换为解压BundleInfo
		/// </summary>
		public static BundleInfo ConvertToUnpackInfo(PackageBundle packageBundle)
		{
			// 注意：我们把流加载路径指定为远端下载地址
			string streamingPath = PersistentTools.ConvertToWWWPath(packageBundle.StreamingFilePath);
			BundleInfo bundleInfo = new BundleInfo(packageBundle, BundleInfo.ELoadMode.LoadFromStreaming, streamingPath, streamingPath);
			return bundleInfo;
		}

		/// <summary>
		/// 批量转换解压为BundleInfo
		/// </summary>
		public static List<BundleInfo> ConvertToUnpackInfos(List<PackageBundle> unpackList)
		{
			List<BundleInfo> result = new List<BundleInfo>(unpackList.Count);
			foreach (var packageBundle in unpackList)
			{
				var bundleInfo = ConvertToUnpackInfo(packageBundle);
				result.Add(bundleInfo);
			}
			return result;
		}
	}
}