using NPOI.SS.Formula.Functions;
using Prism.Commands;
using Prism.Common;
using Prism.Events;
using Prism.Ioc;
using Prism.Mvvm;
using Prism.Regions;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Data.Entity;
using System.Linq;
using System.Threading.Tasks;
using TeamAAS_VP.Core;
using TeamAAS_VP.Data;
using TeamAAS_VP.Events;
using TeamAAS_VP.Interfaces;
using TeamAAS_VP.Models;
using TeamAAS_VP.Resources.Languages;
using TeamAAS_VP.Views.User;

namespace TeamAAS_VP.ViewModels.User
{
    public class LoginViewModel : BindableBase
    {
        private readonly IRegionManager _regionManager;
        private readonly IEventAggregator _eventAggregator;
        private readonly IContainerProvider _container;
        private readonly ISystemDatabaseService _systemDatabaseService;

		private List<TeamAAS_VP.Models.User> Users;
        #region 属性
        private ObservableCollection<string> _UserNameList;

        /// <summary>
        /// 用户列表
        /// </summary>
        public ObservableCollection<string> UserNameList
        {
            get { return _UserNameList; }
            set { _UserNameList = value; }
        }

        public string SelectedUserName { get; set; }

        public string UserPassword { get; set; }

        public bool IsRemember { get; set; }

        #endregion

        #region 命令
        /// <summary>
        /// 注册命令
        /// </summary>
        public DelegateCommand SignUpCommand { get; set; }
        /// <summary>
        /// 登录命令
        /// </summary>
        public DelegateCommand LoginCommand { get; set; }
        public DelegateCommand LoadedCommand { get; set; }

        private DelegateCommand _CardLoginCommand;
        public DelegateCommand CardLoginCommand =>
            _CardLoginCommand ?? (_CardLoginCommand = new DelegateCommand(ExecuteCardLoginCommand));

        
        #endregion

        #region 事件

        #endregion

        public LoginViewModel(IRegionManager regionManager, IEventAggregator ea, IContainerProvider container, ISystemDatabaseService systemDatabaseService)
        {
            _regionManager = regionManager;
            _eventAggregator = ea;
            _container = container;
            _systemDatabaseService = systemDatabaseService;

			LoadedCommand = new DelegateCommand(OnLoad);
            SignUpCommand = new DelegateCommand(new Action(SignUp));
            LoginCommand = new DelegateCommand(async () => await LoginAsync());

            UserNameList = new ObservableCollection<string>();

            // load users from system database (sync-block safe call)
            try
            {
                Users = _systemDatabaseService.GetAllUsersAsync().GetAwaiter().GetResult()?.ToList();
            }
            catch
            {
                Users = new List<TeamAAS_VP.Models.User>();
            }

            TeamAAS_VP.Models.User rememberUser = null;
            if (Users != null)
            {
                foreach (var user in Users)
                {
                    UserNameList.Add(user.UserName);
                    if (user.IsRemember)
                    {
                        rememberUser = user;
                    }
                }
            }

            //对记住的用户界面绑定
            if (rememberUser != null)
            {
                SelectedUserName = rememberUser.UserName;
                UserPassword = rememberUser.UserPassword;
                IsRemember = true;
            }
        }

        #region 方法
        private async Task LoginAsync()
        {
            if (Users == null || string.IsNullOrEmpty(SelectedUserName) || UserPassword == null)
                return;

            if (_systemDatabaseService.GetCurrentUser() != null)
            {
                if (_systemDatabaseService.GetCurrentUser().UserName == SelectedUserName)
                {
                    return;
                }
            }

            try
            {
                // authenticate via system database service
                var user = await _systemDatabaseService.AuthenticateUserAsync(SelectedUserName, UserPassword);
                if (user != null)
                {
                    // set remember flag via system database service
                    try
                    {
                        if (IsRemember)
                            await _systemDatabaseService.SetRememberUserAsync(SelectedUserName);
                        else
                            await _systemDatabaseService.ClearRememberUserAsync();
                    }
                    catch
                    {
                        
                    }

                    // mark current user in system DB and record login
                    await _systemDatabaseService.SetCurrentUserAsync(user.Id);
                    //await _systemDatabaseService.RecordUserLoginAsync(new UserLoginRecord { UserId = user.Id, Success = true, Time = DateTime.UtcNow, Message = "Login success" });

                    _eventAggregator.GetEvent<SnackbarMessageNotification>().Publish(new MessageParameter() { Msg = $"{Lang.登录成功}！", Duration = 1 });
                    _eventAggregator.GetEvent<UserLoginNotification>().Publish(user);
                }
            }
            catch (Exception ex)
            {
                // authentication failed or error
                await _systemDatabaseService.RecordUserLoginAsync(new UserLoginRecord { UserId = 0, Success = false, Time = DateTime.UtcNow, Message = $"Login failed for {SelectedUserName}: {ex.Message}" });
                _eventAggregator.GetEvent<SnackbarMessageNotification>().Publish(new MessageParameter() { Msg = Lang.密码错误, Duration = 1 });
            }
        }

        private void SignUp()
        {
            var management = _container.Resolve<Management>();
            if (_systemDatabaseService.GetCurrentUser().userPart != Enums.UserPart.Administrator)
            {
                _eventAggregator.GetEvent<SnackbarMessageNotification>().Publish(new MessageParameter() { Msg = Lang.当前用户权限不足, Duration = 1 });
                return;
            }

            _regionManager.RequestNavigate("UserRegionContext", "SignUpView");
        }

        private void OnLoad()
        {

        }

        /// <summary>
        /// 更新用户列表
        /// </summary>
        public void UpdateUserList()
        {
            UserNameList.Clear();
            //获取所有用户
            try
            {
                Users = _systemDatabaseService.GetAllUsersAsync().GetAwaiter().GetResult()?.ToList();
            }
            catch
            {
                Users = new List<TeamAAS_VP.Models.User>();
            }

            TeamAAS_VP.Models.User rememberUser = null;
            if (Users != null)
            {
                foreach (var user in Users)
                {
                    UserNameList.Add(user.UserName);
                    if (user.IsRemember)
                    {
                        rememberUser = user;
                    }
                }
            }
            //对记住的用户界面绑定
            if (rememberUser != null)
            {
                SelectedUserName = rememberUser.UserName;
                UserPassword = rememberUser.UserPassword;
                IsRemember = true;
            }
        }

        /// <summary>
        /// 刷卡登录命令
        /// </summary>
        void ExecuteCardLoginCommand()
        {
            var cardLogin = _container.Resolve<CardLoginWindow>();
            var result = cardLogin.ShowDialog();
            if (result is bool st1 && !st1)
            {
                
            }
        }
        #endregion
    }
}