using Avalonia;
using Avalonia.Controls;
using Avalonia.Controls.Primitives;
using Avalonia.Controls.Templates;
using Avalonia.Data;
using Avalonia.Input;
using Avalonia.Interactivity;
using Avalonia.Media;
using LehrerApp.Core.Models;
using LehrerApp.Desktop.ViewModels.Groups;

namespace LehrerApp.Desktop.Views.Groups;

public partial class AttendanceHomeworkQuickInputDialog : Window
{
    public AttendanceHomeworkQuickInputDialog()
    {
        InitializeComponent();
        BuildColumns();
    }

    protected override void OnOpened(EventArgs e)
    {
        base.OnOpened(e);
        StatusGrid.Focus();
        if (ViewModel?.SelectedRow is { } row)
            StatusGrid.ScrollIntoView(row, null);
    }

    private void BuildColumns()
    {
        StatusGrid.Columns.Add(new DataGridTextColumn
        {
            Header = "Schüler",
            Binding = new Binding(nameof(ParticipationStudentRow.Name)),
            Width = new DataGridLength(1, DataGridLengthUnitType.Star),
        });
        StatusGrid.Columns.Add(new DataGridTemplateColumn
        {
            Header = "Anwesenheit",
            Width = new DataGridLength(210, DataGridLengthUnitType.Pixel),
            CellTemplate = BuildAttendanceTemplate(),
        });
        StatusGrid.Columns.Add(new DataGridTemplateColumn
        {
            Header = "Hausaufgaben",
            Width = new DataGridLength(270, DataGridLengthUnitType.Pixel),
            CellTemplate = BuildHomeworkTemplate(),
        });
    }

    private IDataTemplate BuildAttendanceTemplate() =>
        new FuncDataTemplate<ParticipationStudentRow>((row, _) =>
        {
            if (row is null) return new TextBlock();
            var button = StatusButton(185);
            var flyout = new MenuFlyout { Placement = PlacementMode.BottomEdgeAlignedLeft };
            AddAttendanceItem(flyout, row, "·  Nicht kontrolliert", null);
            AddAttendanceItem(flyout, row, "✓  Anwesend", AttendanceStatus.Present);
            AddAttendanceItem(flyout, row, "?  Entschuldigung offen", AttendanceStatus.ExcusePending);
            AddAttendanceItem(flyout, row, "⊘  Krank, entschuldigt", AttendanceStatus.Excused);
            AddAttendanceItem(flyout, row, "!  Unentschuldigt", AttendanceStatus.Unexcused);
            AddAttendanceItem(flyout, row, "✕  Geschwänzt", AttendanceStatus.Truant);
            AddAttendanceItem(flyout, row, "◇  Andere Schulveranstaltung", AttendanceStatus.OtherSchoolEvent);
            button.Flyout = flyout;

            void Refresh()
            {
                UpdateButton(button,
                    string.IsNullOrEmpty(row.AttendanceLabel) ? "·" : row.AttendanceLabel,
                    row.AttendanceTooltip, AttendanceDisplay.Color(row.Attendance));
            }
            Refresh();
            row.PropertyChanged += (_, args) =>
            {
                if (args.PropertyName == nameof(ParticipationStudentRow.AttendanceLabel)) Refresh();
            };
            return Center(button);
        });

    private IDataTemplate BuildHomeworkTemplate() =>
        new FuncDataTemplate<ParticipationStudentRow>((row, _) =>
        {
            if (row is null) return new TextBlock();
            var button = StatusButton(245);
            var flyout = new MenuFlyout { Placement = PlacementMode.BottomEdgeAlignedLeft };
            AddHomeworkItem(flyout, row, "·  Keine Hausaufgabe", null);
            AddHomeworkItem(flyout, row, "✓  Gemacht", HomeworkStatus.Completed);
            AddHomeworkItem(flyout, row, "◐  Teilweise, Rest offen", HomeworkStatus.PartiallyCompleted);
            AddHomeworkItem(flyout, row, "◕  Rest nachgereicht", HomeworkStatus.PartialSubmittedLate);
            AddHomeworkItem(flyout, row, "◒  Rest nicht nachgereicht", HomeworkStatus.PartialMissingOverdue);
            AddHomeworkItem(flyout, row, "!  Nicht gemacht, Nachreichen offen", HomeworkStatus.MissingOpen);
            AddHomeworkItem(flyout, row, "✕  Nicht mehr nachgereicht", HomeworkStatus.MissingOverdue);
            AddHomeworkItem(flyout, row, "↺  Nachgereicht", HomeworkStatus.SubmittedLate);
            button.Flyout = flyout;

            void Refresh() => UpdateButton(button, row.HomeworkSymbol, row.HomeworkTooltip,
                HomeworkDisplay.Color(row.Homework));
            Refresh();
            row.PropertyChanged += (_, args) =>
            {
                if (args.PropertyName == nameof(ParticipationStudentRow.HomeworkSymbol)) Refresh();
            };
            return Center(button);
        });

    private void AddAttendanceItem(MenuFlyout flyout, ParticipationStudentRow row,
        string header, AttendanceStatus? status)
    {
        var item = new MenuItem { Header = header };
        item.Click += (_, _) => ViewModel?.ApplyAttendance(row, status);
        flyout.Items.Add(item);
    }

    private void AddHomeworkItem(MenuFlyout flyout, ParticipationStudentRow row,
        string header, HomeworkStatus? status)
    {
        var item = new MenuItem { Header = header };
        item.Click += (_, _) => ViewModel?.ApplyHomework(row, status);
        flyout.Items.Add(item);
    }

    private static Button StatusButton(double width) => new()
    {
        Width = width,
        Height = 29,
        Padding = new Thickness(8, 2),
        FontSize = 12,
        HorizontalContentAlignment = Avalonia.Layout.HorizontalAlignment.Center,
    };

    private static Control Center(Control child) => new Grid
    {
        Margin = new Thickness(0, 2),
        HorizontalAlignment = Avalonia.Layout.HorizontalAlignment.Center,
        Children = { child },
    };

    private static void UpdateButton(Button button, string symbol, string tooltip, string color)
    {
        button.Content = $"{symbol}   {tooltip}";
        ToolTip.SetTip(button, tooltip + " – klicken, um Status auszuwählen");
        if (Color.TryParse(color, out var parsed))
        {
            button.Background = new SolidColorBrush(parsed);
            button.Foreground = Brushes.White;
            button.Opacity = 1;
        }
        else
        {
            button.ClearValue(Button.BackgroundProperty);
            button.ClearValue(Button.ForegroundProperty);
            button.Opacity = 0.48;
        }
    }

    protected override void OnKeyDown(KeyEventArgs e)
    {
        var vm = ViewModel;
        var row = vm?.SelectedRow;
        if (vm is null || row is null) { base.OnKeyDown(e); return; }

        if (e.KeyModifiers.HasFlag(KeyModifiers.Alt))
        {
            var homework = e.Key switch
            {
                Key.D0 or Key.NumPad0 => (HomeworkStatus?)null,
                Key.M => HomeworkStatus.Completed,
                Key.T => HomeworkStatus.PartiallyCompleted,
                Key.R => HomeworkStatus.PartialSubmittedLate,
                Key.X => HomeworkStatus.PartialMissingOverdue,
                Key.O => HomeworkStatus.MissingOpen,
                Key.F => HomeworkStatus.MissingOverdue,
                Key.S => HomeworkStatus.SubmittedLate,
                _ => null,
            };
            var recognized = e.Key is Key.D0 or Key.NumPad0 or Key.M or Key.T or Key.R or Key.X or Key.O or Key.F or Key.S;
            if (recognized)
            {
                vm.ApplyHomework(row, homework);
                BringSelectionIntoView();
                e.Handled = true;
                return;
            }
        }

        AttendanceStatus? attendance = e.Key switch
        {
            Key.A => AttendanceStatus.Present,
            Key.K => AttendanceStatus.ExcusePending,
            Key.E => AttendanceStatus.Excused,
            Key.U => AttendanceStatus.Unexcused,
            Key.G => AttendanceStatus.Truant,
            Key.V => AttendanceStatus.OtherSchoolEvent,
            _ => null,
        };
        var attendanceRecognized = e.Key is Key.D0 or Key.NumPad0 or Key.A or Key.K or Key.E or Key.U or Key.G or Key.V;
        if (attendanceRecognized)
        {
            vm.ApplyAttendance(row, attendance);
            BringSelectionIntoView();
            e.Handled = true;
            return;
        }

        switch (e.Key)
        {
            case Key.Up: vm.MoveSelection(-1); BringSelectionIntoView(); e.Handled = true; break;
            case Key.Down or Key.Enter: vm.MoveSelection(1); BringSelectionIntoView(); e.Handled = true; break;
            case Key.Escape: Close(); e.Handled = true; break;
            default: base.OnKeyDown(e); break;
        }
    }

    private AttendanceHomeworkQuickInputViewModel? ViewModel =>
        DataContext as AttendanceHomeworkQuickInputViewModel;

    private void BringSelectionIntoView()
    {
        if (ViewModel?.SelectedRow is { } row)
            StatusGrid.ScrollIntoView(row, null);
    }

    private void OnClose(object? sender, RoutedEventArgs e) => Close();
}