using Avalonia.Controls;
using Avalonia.Data;
using LehrerApp.Core.Interfaces;
using LehrerApp.Core.Services;
using LehrerApp.Desktop.ViewModels.Groups;
using Microsoft.Extensions.DependencyInjection;

namespace LehrerApp.Desktop.Views.Groups;

public partial class GradeOverviewTabView : UserControl
{
    private GradeOverviewTabViewModel? _vm;

    public GradeOverviewTabView() => InitializeComponent();

    protected override void OnDataContextChanged(EventArgs e)
    {
        base.OnDataContextChanged(e);

        if (DataContext is GradeOverviewTabViewModel vm)
        {
            _vm = vm;
            vm.OnManageStudentGrades = ShowStudentGradesDialog;
            vm.OnCollectiveGrade = ShowCollectiveGradeDialog;
            vm.OnReportGrades = ShowReportGradesDialog;
            vm.PropertyChanged += (_, pe) =>
            {
                if (pe.PropertyName == nameof(GradeOverviewTabViewModel.RebuildColumnsSignal))
                    BuildColumns();
            };
            BuildColumns();
        }
    }

    private async Task ShowStudentGradesDialog(GradeOverviewRow row)
    {
        var dialogVm = new StudentGradesDialogViewModel(
            App.Services.GetRequiredService<IGradeRepository>(),
            row.StudentId, _vm!.GroupId, row.Name);

        var dialog = new StudentGradesDialog { DataContext = dialogVm };
        var owner = TopLevel.GetTopLevel(this) as Window;
        if (owner is not null) await dialog.ShowDialog(owner);
    }

    private async Task ShowCollectiveGradeDialog()
    {
        var dialogVm = new CollectiveGradeDialogViewModel(
            App.Services.GetRequiredService<IGradeRepository>(),
            App.Services.GetRequiredService<IStudentRepository>(),
            _vm!.GroupId);

        var dialog = new CollectiveGradeDialog { DataContext = dialogVm };
        var owner = TopLevel.GetTopLevel(this) as Window;
        if (owner is not null) await dialog.ShowDialog(owner);
    }

    private async Task ShowReportGradesDialog()
    {
        var dialogVm = new ReportGradeDialogViewModel(
            App.Services.GetRequiredService<IGradeRepository>(),
            App.Services.GetRequiredService<IExamRepository>(),
            App.Services.GetRequiredService<IExamResultRepository>(),
            App.Services.GetRequiredService<IStudentRepository>(),
            App.Services.GetRequiredService<IGroupMembershipRepository>(),
            App.Services.GetRequiredService<IGradingSchemeRepository>(),
            App.Services.GetRequiredService<IReportGradeRepository>(),
            App.Services.GetRequiredService<GradingService>(),
            _vm!.GroupId, _vm.GroupType, _vm.GradingSystem, _vm.GroupLabel);

        var dialog = new ReportGradeDialog { DataContext = dialogVm };
        var owner = TopLevel.GetTopLevel(this) as Window;
        if (owner is not null) await dialog.ShowDialog(owner);
    }

    private void BuildColumns()
    {
        var grid = this.FindControl<DataGrid>("GradesGrid");
        if (grid is null || _vm is null) return;

        grid.Columns.Clear();
        grid.Columns.Add(new DataGridTextColumn
        {
            Header  = "Schüler",
            Binding = new Binding("Name"),
            Width   = new DataGridLength(160, DataGridLengthUnitType.Pixel),
        });

        foreach (var (col, i) in _vm.Columns.Select((c, i) => (c, i)))
        {
            var idx = i;
            grid.Columns.Add(new DataGridTextColumn
            {
                Header  = col.Header,
                Binding = new Binding($"Cells[{idx}]"),
                Width   = new DataGridLength(120, DataGridLengthUnitType.Pixel),
            });
        }

        grid.Columns.Add(new DataGridTextColumn
        {
            Header  = "Gesamt",
            Binding = new Binding("TotalDisplay"),
            Width   = new DataGridLength(80, DataGridLengthUnitType.Pixel),
        });
    }
}