using System.Collections;
using System.Collections.Generic;
using System.Security.Cryptography;
using System.Linq;
using System.IO;
using UnityEngine;
using UnityEditor;

public class BundleHelper
{

  static string TempPath = Application.temporaryCachePath + "/PackData";
  static string TargetPath = Application.dataPath + "/StreamingAssets/PackData"; // or Application.streamingAssetsPath
  static string MainBundleName = "PackData";
  static string MainBundle = TargetPath + "/PackData";
  static string ManifestFile = Application.dataPath + "/Resources/bundles.manifest";

  [MenuItem("Build/Build bundles")]
  public static void BuildBundles()
  {
    if(!Directory.Exists(TempPath))
      Directory.CreateDirectory(TempPath);
    BuildAssetBundleOptions options = BuildAssetBundleOptions.None;
    options |= BuildAssetBundleOptions.ChunkBasedCompression;
    options |= BuildAssetBundleOptions.DeterministicAssetBundle;
    options |= BuildAssetBundleOptions.ForceRebuildAssetBundle;
    options |= BuildAssetBundleOptions.StrictMode;
#if UNITY_IOS
    BuildPipeline.BuildAssetBundles(TempPath, options, BuildTarget.iOS);
#elif UNITY_ANDROID
    BuildPipeline.BuildAssetBundles(TempPath, options, BuildTarget.Android);
#else
    BuildPipeline.BuildAssetBundles(TempPath, options, BuildTarget.StandaloneWindows);
#endif
    Debug.Log("Bundle生成结束");
    // Move to StreamingAssets
    if (!Directory.Exists(TargetPath))
      Directory.CreateDirectory(TargetPath);
    string[] files = Directory.GetFiles(TempPath, "*.*");
    string dirPath = null;
    foreach(string file in files)
    {
      if (!file.EndsWith(".manifest") && !file.EndsWith(".meta"))
      {
        dirPath = file.Replace('\\', '/');
        dirPath = dirPath.Replace(TempPath, TargetPath);
        if (File.Exists(dirPath))
          File.Delete(dirPath);
        File.Move(file, dirPath);
      }
    }
    // 将bundle的md5写入bundles.manifest文件
    AssetBundle mainBundle = AssetBundle.LoadFromFile(MainBundle);
    if (mainBundle != null)
    {
      AssetBundleManifest manifest = mainBundle.LoadAsset<AssetBundleManifest>("AssetBundleManifest");
      if (manifest != null)
      {
        if (File.Exists(ManifestFile))
          File.Delete(ManifestFile);
        using (StreamWriter file = new System.IO.StreamWriter(ManifestFile, true))
        {
          string[] bundles = manifest.GetAllAssetBundles();
          List<string> _bundles = bundles.ToList<string>();
          _bundles.Add(MainBundleName);
          foreach (string bundle in _bundles)
          {
            string path = TargetPath + "/" + bundle ;
            if (!File.Exists(path))
              continue;
            long size = new FileInfo(path).Length;
            byte[] data = File.ReadAllBytes(path);
            string hash = FileUtil.GetMD5Hash(data);
            file.WriteLine(bundle + "," + size + "," + hash);
          }
        };
      }
      mainBundle.Unload(true);
    }
  }

}