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 TeamAAS_VP.Data;
using TeamAAS_VP.Events;
using TeamAAS_VP.Core;
using TeamAAS_VP.Models;
using TeamAAS_VP.Resources.Languages;

namespace TeamAAS_VP.ViewModels.User
{
    public class LoginViewModel : BindableBase
    {
        IRegionManager _regionManager;
        IEventAggregator _eventAggregator;
        IContainerProvider _container;
        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; }
        #endregion

        #region 事件

        #endregion

        public LoginViewModel(IRegionManager regionManager, IEventAggregator ea,IContainerProvider container)
        {
            _regionManager= regionManager;
            _eventAggregator = ea;
            _container= container;
            LoadedCommand = new DelegateCommand(OnLoad);
            SignUpCommand = new DelegateCommand(new Action(SignUp));
            LoginCommand = new DelegateCommand(new Action(Login));

            UserNameList = new ObservableCollection<string>();
            //获取所有用户
            Users = DatabaseHelper.GetAllUser();
            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 void Login()
        {
            if (Users == null || string.IsNullOrEmpty(SelectedUserName) || UserPassword==null)
                return;


            
            var management = _container.Resolve<Management>();
            if (management.CurrentUser != null)
            {
                if (management.CurrentUser.UserName == SelectedUserName)
                {
                    return;
                }
            }

            // 使用 LINQ 查询检查是否存在具有指定用户名和密码的用户
            bool userExists = Users.Any(user => user.UserName == SelectedUserName && user.UserPassword == UserPassword);
            if (userExists)
            {
                if (IsRemember)
                    DatabaseHelper.RememberUser(SelectedUserName);
                else
                    DatabaseHelper.NotRememberUser();
                _eventAggregator.GetEvent<SnackbarMessageNotification>().Publish(new MessageParameter() { Msg= $"{Lang.登录成功}！", Duration=1});
                var user = Users.FirstOrDefault(u => u.UserName == SelectedUserName);
                management.CurrentUser = user;
                _eventAggregator.GetEvent<UserLoginNotification>().Publish(user);
                //Growl.SuccessGlobal("登录成功！");
            }
            else
            {
                _eventAggregator.GetEvent<SnackbarMessageNotification>().Publish(new MessageParameter() { Msg = Lang.密码错误, Duration = 1 });
                //Growl.WarningGlobal("密码错误！");
            }
        }

        private void SignUp()
        {
            var management = _container.Resolve<Management>();
            if (management.CurrentUser.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
            Users = DatabaseHelper.GetAllUser();
            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;
            }
        }
        #endregion
    }
}