using Google.Apis.Auth.OAuth2;
using Google.Apis.Drive.v3;
using Google.Apis.Services;
using Google.Apis.Util.Store;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace PDF_Office.ViewModels.HomePanel.CloudDrive
{
    //多用户UX交互
    public class GoogleDriveManager
    {
        public static string[] Scopes = { DriveService.Scope.Drive };
        //Google Drive应用名称
        private static readonly string GoogleDriveAppName = "PDF Office";
        //请求应用进行身份验证的信息
        public static string CredentialsPath { get; private set; }
        //存放已通过身份验证的用户信息，以便下次不用登录便可使用云文档
        public static string FilesPathTemp { get; private set; }

        //已登录的用户们
        public List<GoogleDriveUserItem> GoogleDriveUsers = new List<GoogleDriveUserItem>();


        public GoogleDriveManager()
        {
            GetFilesPathTemp();
            GetCredentialsPath();
        }


        #region  云文档的用户帐户缓存路径和身份验证文件

        /// <summary>
        /// 获取或创建缓存登录帐户信息
        /// </summary>
        public void GetFilesPathTemp()
        {
            string str_1 = System.AppDomain.CurrentDomain.BaseDirectory;
            String FolderPath = str_1 + "GoogleDriveUsers";

            if (Directory.Exists(FolderPath) == false)
                Directory.CreateDirectory(FolderPath);

            FilesPathTemp = FolderPath;
        }

        /// <summary>
        /// 获取本地身份验证文件
        /// </summary>
        public void GetCredentialsPath()
        {
            string str_1 = System.AppDomain.CurrentDomain.BaseDirectory;
            String filePath = str_1 + @"\credentials.json";
            CredentialsPath = filePath;
        }

        #endregion


        #region   请求身份验证

        /// <summary>
        /// 获取登录过的用户
        /// </summary>
        public async Task<bool> GetHistoryUsers()
        {
            var tuples = await GetHistoryService();
            GoogleDriveUsers.Clear();
            foreach (var tuple in tuples)
            {

                if (tuple != null && tuple.Item1 != null && tuple.Item2 != null)
                {
                    AddGoogleDriveUser(tuple);
                }
            }

            if (GoogleDriveUsers.Count > 0)
            {
                return true;
            }
            return false;
        }

        public async void AddGoogleDriveUser(Tuple<DriveService, UserCredential> tuple)
        {
            GoogleDriveUserItem user = new GoogleDriveUserItem();
            user.Service = tuple.Item1;
            user.User.CurrentCredential = tuple.Item2;
            user.User.UserAccount = await user.GetUserAcountAsync();
            GoogleDriveUsers.Add(user);
        }



        /// <summary>
        /// 获取登录过的账号
        /// </summary>
        /// <returns>历史账号</returns>
        private async Task<List<Tuple<DriveService, UserCredential>>> GetHistoryService()
        {
            DirectoryInfo TheFolder = new DirectoryInfo(GoogleDriveManager.FilesPathTemp);
            List<Tuple<DriveService, UserCredential>> DriveServices = new List<Tuple<DriveService, UserCredential>>();

            foreach (var directorieItem in TheFolder.GetDirectories())
            {
                var driveServiceItem = await GetServiceAsync(directorieItem.Name);

                if (driveServiceItem != null)
                {
                    DriveServices.Add(driveServiceItem);
                }
            }
            return DriveServices;
        }

        /// <summary>
        ///  异步获取Google服务的包信息，避免UI线程卡死
        /// </summary>
        /// <param name="userInfoFile"></param>
        [Obsolete]
        public async Task<Tuple<DriveService, UserCredential>> GetServiceAsync(string userInfoFile = "")
        {
            Tuple<DriveService, UserCredential> tuple = null;
            await Task.Run(() =>
            {
                tuple = GetService(userInfoFile);
            });
            return tuple;
        }

        /// <summary>
        /// 获取Google服务的包信息（包含访问令牌，App Key密钥等）
        /// </summary>
        /// <param name="FilePath">登录过的用户文件；若为空，则为新用户登录</param>
        /// <returns></returns>
        [Obsolete]
        private Tuple<DriveService, UserCredential> GetService(string FilePath = "")
        {
            Tuple<DriveService, UserCredential> tuple = null;
            UserCredential credential;

            if (FilePath == "")
            {
                var time = DateTime.Now.ToString("yyyyMMddHHmmss");
                FilePath = System.IO.Path.Combine(GoogleDriveManager.FilesPathTemp, time + ".json");
            }


            using (var stream = new FileStream(GoogleDriveManager.CredentialsPath, FileMode.Open, FileAccess.Read))
            {
                credential = GoogleWebAuthorizationBroker.AuthorizeAsync(
                    GoogleClientSecrets.Load(stream).Secrets,
                    Scopes,
                    "user",
                    CancellationToken.None,
                    new FileDataStore(FilePath, true)).Result;
            }

            //create Drive API service.
            DriveService service = new DriveService(new BaseClientService.Initializer()
            {
                HttpClientInitializer = credential,
                ApplicationName = GoogleDriveAppName
            });

            return tuple = new Tuple<DriveService, UserCredential>(service, credential);
        }


        #endregion
    }
}