using LocalhostMES.DataBase;
using LocalhostMES.Core;
using LocalhostMES.Models;
using Prism.Commands;
using Prism.Mvvm;
using System;
using System.Collections.ObjectModel;
using System.Windows;

namespace LocalhostMES.ViewModels.Tabs
{
    public class PartCatalogViewModel : BindableBase
    {
        public PartCatalogViewModel()
        {
            LoadedCommand = new DelegateCommand(OnLoaded);
            AddCommand = new DelegateCommand(AddParkingLot);
            UpdateCommand = new DelegateCommand(UpdateParkingLot, CanUpdate).ObservesProperty(() => IsEditMode);
            DeleteCommand = new DelegateCommand<ParkingLot>(DeleteParkingLot);
            EditCommand = new DelegateCommand<ParkingLot>(EditParkingLot);
            ClearFormCommand = new DelegateCommand(ClearForm);
            CancelEditCommand = new DelegateCommand(CancelEdit);
            MesDataChangedNotifier.Changed += OnDataChanged;
        }
        public DelegateCommand LoadedCommand { get; }
        public DelegateCommand AddCommand { get; }
        public DelegateCommand UpdateCommand { get; }
        public DelegateCommand<ParkingLot> DeleteCommand { get; }
        public DelegateCommand<ParkingLot> EditCommand { get; }
        public DelegateCommand ClearFormCommand { get; }
        public DelegateCommand CancelEditCommand { get; }

        private ObservableCollection<ParkingLot> _parkingLots = new ObservableCollection<ParkingLot>();
        public ObservableCollection<ParkingLot> ParkingLots
        {
            get => _parkingLots;
            set => SetProperty(ref _parkingLots, value);
        }

        private ParkingLot _currentParkingLot = new ParkingLot();
        public ParkingLot CurrentParkingLot
        {
            get => _currentParkingLot;
            set => SetProperty(ref _currentParkingLot, value);
        }

        private ParkingLot _selectedParkingLot;
        public ParkingLot SelectedParkingLot
        {
            get => _selectedParkingLot;
            set => SetProperty(ref _selectedParkingLot, value);
        }

        private bool _isEditMode;
        public bool IsEditMode
        {
            get => _isEditMode;
            set => SetProperty(ref _isEditMode, value);
        }
        private void OnLoaded()
        {
            ReloadParkingLots();
        }
        private void ReloadParkingLots()
        {
            ParkingLots = new ObservableCollection<ParkingLot>(DatabaseHelper.SelectParkingLot());
        }

        private void AddParkingLot()
        {
            if (!ValidateParkingLot())
            {
                return;
            }

            var row = new ParkingLot
            {
                PartName = CurrentParkingLot.PartName?.Trim(),
                Quantity = CurrentParkingLot.Quantity
            };

            if (DatabaseHelper.InsertParkingLot(row))
            {
                MessageBox.Show("添加成功！", "提示", MessageBoxButton.OK, MessageBoxImage.Information);
                ReloadParkingLots();
                ClearForm();
            }
            else
            {
                MessageBox.Show("添加失败（可能已存在相同记录）。", "提示", MessageBoxButton.OK, MessageBoxImage.Warning);
            }
        }

        private void EditParkingLot(ParkingLot parkingLot)
        {
            if (parkingLot == null)
            {
                return;
            }

            CurrentParkingLot = new ParkingLot
            {
                Id = parkingLot.Id,
                PartName = parkingLot.PartName,
                Quantity = parkingLot.Quantity
            };

            IsEditMode = true;
            SelectedParkingLot = parkingLot;
        }

        private void UpdateParkingLot()
        {
            if (!ValidateParkingLot() || SelectedParkingLot == null)
            {
                return;
            }

            SelectedParkingLot.PartName = CurrentParkingLot.PartName?.Trim();
            SelectedParkingLot.Quantity = CurrentParkingLot.Quantity;

            if (DatabaseHelper.UpdateParkingLot(SelectedParkingLot))
            {
                MessageBox.Show("更新成功！", "提示", MessageBoxButton.OK, MessageBoxImage.Information);
                CancelEdit();
                ReloadParkingLots();
            }
            else
            {
                MessageBox.Show("更新失败。", "提示", MessageBoxButton.OK, MessageBoxImage.Warning);
            }
        }

        private bool CanUpdate() => IsEditMode;

        private void DeleteParkingLot(ParkingLot parkingLot)
        {
            if (parkingLot == null)
            {
                return;
            }

            var result = MessageBox.Show($"确定要删除零件「{parkingLot.PartName}」吗？",
                "确认删除", MessageBoxButton.YesNo, MessageBoxImage.Warning);

            if (result != MessageBoxResult.Yes)
            {
                return;
            }

            if (DatabaseHelper.DeleteParkingLot(parkingLot.Id))
            {
                if (IsEditMode && SelectedParkingLot == parkingLot)
                {
                    CancelEdit();
                }

                ReloadParkingLots();
            }
            else
            {
                MessageBox.Show("删除失败。", "提示", MessageBoxButton.OK, MessageBoxImage.Warning);
            }
        }

        private void ClearForm()
        {
            CurrentParkingLot = new ParkingLot();
        }

        private void CancelEdit()
        {
            IsEditMode = false;
            ClearForm();
            SelectedParkingLot = null;
        }

        private bool ValidateParkingLot()
        {
            if (string.IsNullOrWhiteSpace(CurrentParkingLot.PartName))
            {
                MessageBox.Show("名称不能为空。", "验证", MessageBoxButton.OK, MessageBoxImage.Warning);
                return false;
            }

            if (CurrentParkingLot.Quantity < 0)
            {
                MessageBox.Show("数量不能为负数。", "验证", MessageBoxButton.OK, MessageBoxImage.Warning);
                return false;
            }

            return true;
        }

        private void OnDataChanged(object sender, MesDataChangedEventArgs e)
        {
            if (!e.Has(MesDataScope.ParkingLot))
            {
                return;
            }

            Application.Current?.Dispatcher.Invoke(ReloadParkingLots);
        }
    }
}