using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Input;
using System.Windows.Media;

namespace JJServiceManager
{
    /// <summary>추가 선택 화면: Windows 서비스 전체 목록에서 관리할 서비스를 고름</summary>
    public sealed class ServicePickerWindow : Window
    {
        private readonly HashSet<string> _registered;
        private readonly DataGrid _grid;
        private readonly TextBox _search;
        private readonly CheckBox _onlySelected;
        private readonly TextBlock _loading;
        private readonly TextBlock _status;
        private List<ServiceInfo> _all = new List<ServiceInfo>();
        private ICollectionView _view;

        /// <summary>선택완료 시 체크된 서비스 (순서: 이름순)</summary>
        public List<ServiceInfo> Result { get; private set; }

        public ServicePickerWindow(IEnumerable<string> registeredNames)
        {
            _registered = new HashSet<string>(registeredNames, StringComparer.OrdinalIgnoreCase);

            Title = "추가 선택 화면 - 서비스 선택";
            Width = 1100;
            Height = 700;
            MinWidth = 700;
            MinHeight = 400;
            FontFamily = new FontFamily("Malgun Gothic");
            FontSize = 13;
            Background = Brushes2.Make("#FAFAFA");
            WindowStartupLocation = WindowStartupLocation.CenterOwner;
            ShowInTaskbar = false;
            AppIcon.Apply(this);

            var root = XamlLoader.LoadElement("ServicePicker.xaml");
            Content = root;

            _grid = root.Find<DataGrid>("grid");
            _search = root.Find<TextBox>("txtSearch");
            _onlySelected = root.Find<CheckBox>("chkOnlySelected");
            _loading = root.Find<TextBlock>("txtLoading");
            _status = root.Find<TextBlock>("txtStatus");

            root.Find<Button>("btnAll").Click += (s, e) => SetVisibleSelected(true);
            root.Find<Button>("btnNone").Click += (s, e) => SetVisibleSelected(false);
            root.Find<Button>("btnDone").Click += (s, e) => Done();
            root.Find<Button>("btnCancel").Click += (s, e) => Close();
            _search.TextChanged += (s, e) => _view?.Refresh();
            _onlySelected.Checked += (s, e) => _view?.Refresh();
            _onlySelected.Unchecked += (s, e) => _view?.Refresh();

            // Space: 마우스로 선택한 줄들의 체크 토글
            _grid.PreviewKeyDown += (s, e) =>
            {
                if (e.Key == Key.Space)
                {
                    var sel = _grid.SelectedItems.Cast<ServiceInfo>().ToList();
                    if (sel.Count > 0)
                    {
                        bool v = !sel.All(x => x.IsSelected);
                        foreach (var x in sel) x.IsSelected = v;
                        e.Handled = true;
                    }
                }
            };
            // 더블클릭: 체크 토글
            _grid.MouseDoubleClick += (s, e) =>
            {
                // 줄 위에서만 (열 제목·스크롤바·체크박스 제외)
                var src = e.OriginalSource as DependencyObject;
                if (FindAncestor<CheckBox>(src) != null) return;
                var row = FindAncestor<DataGridRow>(src);
                if (row?.Item is ServiceInfo si) si.IsSelected = !si.IsSelected;
            };

            KeyDown += (s, e) => { if (e.Key == Key.Escape) Close(); };
            Loaded += async (s, e) => await LoadAsync();
        }

        private static T FindAncestor<T>(DependencyObject d) where T : DependencyObject
        {
            while (d != null)
            {
                if (d is T t) return t;
                d = d is Visual || d is System.Windows.Media.Media3D.Visual3D
                    ? VisualTreeHelper.GetParent(d)
                    : LogicalTreeHelper.GetParent(d);
            }
            return null;
        }

        private async Task LoadAsync()
        {
            _loading.Visibility = Visibility.Visible;
            var reg = _registered;
            _all = await Task.Run(() => ServiceInfo.LoadAll(reg));

            _view = CollectionViewSource.GetDefaultView(_all);
            _view.Filter = Filter;
            // 기본 정렬: 이름 오름차순
            _view.SortDescriptions.Add(new SortDescription(nameof(ServiceInfo.DisplayName), ListSortDirection.Ascending));
            _grid.ItemsSource = _view;
            foreach (var col in _grid.Columns)
                if ((string)col.Header == "이름") col.SortDirection = ListSortDirection.Ascending;

            _loading.Visibility = Visibility.Collapsed;
            if (_all.Count == 0) _status.Text = "서비스 목록을 불러오지 못했습니다.";
        }

        private bool Filter(object o)
        {
            var s = (ServiceInfo)o;
            if (_onlySelected.IsChecked == true && !s.IsSelected) return false;
            var q = _search.Text?.Trim();
            if (string.IsNullOrEmpty(q)) return true;
            return Contains(s.DisplayName, q) || Contains(s.Description, q) || Contains(s.ServiceName, q);
        }

        private static bool Contains(string text, string q)
            => !string.IsNullOrEmpty(text) && text.IndexOf(q, StringComparison.OrdinalIgnoreCase) >= 0;

        private void SetVisibleSelected(bool value)
        {
            if (_view == null) return;
            foreach (ServiceInfo s in _view) s.IsSelected = value;
        }

        private void Done()
        {
            // 목록을 못 불러온 상태에서 선택완료하면 기존 등록이 지워지지 않도록 그냥 닫음
            if (_view == null || _all.Count == 0)
            {
                Close();
                return;
            }
            Result = _all.Where(s => s.IsSelected)
                         .OrderBy(s => s.DisplayName, StringComparer.CurrentCultureIgnoreCase)
                         .ToList();
            DialogResult = true;
        }
    }
}