using FATrace.Model;
using FATrace.WPLApp.Core;
using FATrace.WPLApp.Services;
using FreeSql;
using Prism.Commands;
using Prism.Services.Dialogs;
using System;
using System.Collections.ObjectModel;
using System.Threading.Tasks;
using System.Windows;

namespace FATrace.WPLApp.ViewModels
{
    /// <summary>
    /// 用户新增/编辑 弹窗 VM
    /// </summary>
    public class DialogUserEditViewModel : DialogViewModel
    {
        private readonly IFreeSql _fsql;
        private readonly ILogService _log;

        private string _mode = UserManageViewModel.DialogModes.Add;
        private long _editUserId;

        public DialogUserEditViewModel(IFreeSql fsql, ILogService log)
        {
            _fsql = fsql;
            _log = log;

            AccessLevelOptions = new ObservableCollection<string>(new[]
            {
                UserManageViewModel.AccessLevels.Admin,
                UserManageViewModel.AccessLevels.Operator,
                UserManageViewModel.AccessLevels.Guest
            });

            SaveCommand = new DelegateCommand(async () => await SaveAsync(), () => !IsBusy)
                .ObservesProperty(() => IsBusy);
            CancelCommand = new DelegateCommand(() => OnDialogClosed(ButtonResult.Cancel));
        }

        /// <summary>
        /// 等级下拉选项
        /// </summary>
        public ObservableCollection<string> AccessLevelOptions { get; }

        private string? _userName;
        /// <summary>
        /// 用户名
        /// </summary>
        public string? UserName
        {
            get => _userName;
            set { _userName = value; RaisePropertyChanged(); }
        }

        private string? _password;
        /// <summary>
        /// 密码（当前按现有模型使用明文；如后续需哈希，可在保存处替换）
        /// </summary>
        public string? Password
        {
            get => _password;
            set { _password = value; RaisePropertyChanged(); }
        }

        private string? _accessLevel;
        /// <summary>
        /// 等级
        /// </summary>
        public string? AccessLevel
        {
            get => _accessLevel;
            set { _accessLevel = value; RaisePropertyChanged(); }
        }

        /// <summary>
        /// 保存
        /// </summary>
        public DelegateCommand SaveCommand { get; }

        /// <summary>
        /// 取消
        /// </summary>
        public DelegateCommand CancelCommand { get; }

        /// <summary>
        /// 打开弹窗时初始化
        /// </summary>
        /// <param name="parameters">参数</param>
        public override void OnDialogOpened(IDialogParameters parameters)
        {
            _mode = parameters.GetValue<string>(UserManageViewModel.DialogKeys.Mode) ?? UserManageViewModel.DialogModes.Add;
            Title = _mode == UserManageViewModel.DialogModes.Edit ? "编辑用户" : "新增用户";

            if (_mode == UserManageViewModel.DialogModes.Edit)
            {
                _editUserId = parameters.GetValue<long>(UserManageViewModel.DialogKeys.UserId);
                LoadUser(_editUserId);
            }
            else
            {
                _editUserId = 0;
                UserName = string.Empty;
                Password = string.Empty;
                AccessLevel = UserManageViewModel.AccessLevels.Operator;
            }
        }

        private void LoadUser(long id)
        {
            try
            {
                var user = _fsql.Select<TbUser>().Where(a => a.Id == id).First();
                if (user == null)
                {
                    MessageBox.Show("用户不存在或已被删除", "提示", MessageBoxButton.OK, MessageBoxImage.Warning);
                    return;
                }

                UserName = user.UserName;
                Password = user.Password;
                AccessLevel = user.AccessLevel;
            }
            catch (Exception ex)
            {
                _log.Error($"加载用户失败: {ex}");
                MessageBox.Show($"加载用户失败: {ex.Message}", "错误", MessageBoxButton.OK, MessageBoxImage.Error);
            }
        }

        private async Task SaveAsync()
        {
            if (IsBusy) return;
            try
            {
                if (string.IsNullOrWhiteSpace(UserName))
                {
                    MessageBox.Show("请输入用户名", "提示", MessageBoxButton.OK, MessageBoxImage.Information);
                    return;
                }

                if (string.IsNullOrWhiteSpace(Password))
                {
                    MessageBox.Show("请输入密码", "提示", MessageBoxButton.OK, MessageBoxImage.Information);
                    return;
                }

                if (string.IsNullOrWhiteSpace(AccessLevel))
                {
                    MessageBox.Show("请选择等级", "提示", MessageBoxButton.OK, MessageBoxImage.Information);
                    return;
                }

                IsBusy = true;

                if (_mode == UserManageViewModel.DialogModes.Add)
                {
                    await AddAsync();
                }
                else
                {
                    await UpdateAsync();
                }

                OnDialogClosed(ButtonResult.OK);
            }
            catch (Exception ex)
            {
                _log.Error($"保存用户失败: {ex}");
                MessageBox.Show($"保存失败: {ex.Message}", "错误", MessageBoxButton.OK, MessageBoxImage.Error);
            }
            finally
            {
                IsBusy = false;
            }
        }

        private async Task AddAsync()
        {
            await Task.Run(() =>
            {
                var exists = _fsql.Select<TbUser>().Where(a => a.UserName == UserName).Any();
                if (exists)
                {
                    throw new InvalidOperationException("用户名已存在");
                }

                var entity = new TbUser
                {
                    UserName = UserName!,
                    Password = Password!,
                    AccessLevel = AccessLevel!,
                    CreateTime = DateTime.Now
                };

                _fsql.Insert(entity).ExecuteAffrows();
            });

            _log.Info($"新增用户成功: {UserName}");
        }

        private async Task UpdateAsync()
        {
            var id = _editUserId;
            if (id <= 0) throw new InvalidOperationException("编辑用户Id无效");

            await Task.Run(() =>
            {
                var exists = _fsql.Select<TbUser>().Where(a => a.UserName == UserName && a.Id != id).Any();
                if (exists)
                {
                    throw new InvalidOperationException("用户名已存在");
                }

                var aff = _fsql.Update<TbUser>()
                    .Set(a => a.UserName, UserName!)
                    .Set(a => a.Password, Password!)
                    .Set(a => a.AccessLevel, AccessLevel!)
                    .Where(a => a.Id == id)
                    .ExecuteAffrows();

                if (aff <= 0)
                {
                    throw new InvalidOperationException("更新失败：用户不存在或未发生变化");
                }
            });

            _log.Info($"更新用户成功: Id={id}, UserName={UserName}");
        }
    }
}