LehrerApp/LehrerApp.Desktop/Views/Workload/WorkTaskDialogHelper.cs

using Avalonia.Controls;
using LehrerApp.Core.Interfaces;
using LehrerApp.Core.Models;
using LehrerApp.Core.Services;
using LehrerApp.Desktop.ViewModels.Workload;
using Microsoft.Extensions.DependencyInjection;

namespace LehrerApp.Desktop.Views.Workload;

/// Gemeinsamer Aufruf des Aufgaben-Dialogs für alle drei Entry-Points (Aufgabenliste,
/// Kurs-Dashboard, Hauptdashboard) — vermeidet drei fast identische Kopien der Gruppen-/
/// Kursliste-Ladelogik.
public static class WorkTaskDialogHelper
{
    public static async Task<WorkTask?> ShowDialog(Window owner, WorkTask? source = null,
        bool startAsReminder = false, Guid? preselectedGroupId = null)
    {
        var groups = App.Services.GetRequiredService<IGroupRepository>().GetAll(includeInactive: true);
        var vm = new AddEditWorkTaskDialogViewModel(source, groups, startAsReminder, LoadActiveRoster);
        if (source is null && preselectedGroupId is { } groupId)
            vm.SelectedGroup = groups.FirstOrDefault(g => g.Id == groupId);
        var dialog = new AddEditWorkTaskDialog { DataContext = vm };
        await dialog.ShowDialog<bool>(owner);
        return vm.Result;
    }

    // "Aus Kursliste befüllen" (Nutzer-Feedback): nur aktuell aktive Mitglieder, wie überall sonst
    // im Dashboard/Übersicht-Tab (GroupMembershipService.IsActiveOn).
    private static List<(Guid StudentId, string Name)> LoadActiveRoster(Guid groupId)
    {
        var memberships = App.Services.GetRequiredService<IGroupMembershipRepository>();
        var students = App.Services.GetRequiredService<IStudentRepository>();
        var today = DateOnly.FromDateTime(DateTime.Today);
        return memberships.GetByGroup(groupId)
            .Where(m => GroupMembershipService.IsActiveOn(m, today))
            .Select(m => students.GetById(m.StudentId))
            .Where(s => s is not null)
            .Select(s => (s!.Id, s.FullName))
            .ToList();
    }
}