LehrerApp/LehrerApp.Desktop/Views/Students/DocumentationDialog.axaml.cs

using Avalonia.Controls;
using Avalonia.Interactivity;
using Avalonia.Platform.Storage;
using LehrerApp.Desktop.ViewModels.Students;

namespace LehrerApp.Desktop.Views.Students;

public partial class DocumentationDialog : Window
{
    public DocumentationDialog() => InitializeComponent();

    private void OnSave(object? sender, RoutedEventArgs e)
    {
        if (DataContext is DocumentationDialogViewModel vm)
        {
            vm.SaveCommand.Execute(null);
            if (vm.Result is not null) Close(true);
        }
    }

    private void OnCancel(object? sender, RoutedEventArgs e)
    {
        if (DataContext is DocumentationDialogViewModel vm) vm.DiscardUnsavedAttachments();
        Close(false);
    }

    private async void OnAddAttachment(object? sender, RoutedEventArgs e)
    {
        if (DataContext is not DocumentationDialogViewModel vm) return;

        var files = await StorageProvider.OpenFilePickerAsync(new FilePickerOpenOptions
        {
            Title = "Anhang auswählen", AllowMultiple = false,
        });
        if (files.Count == 0) return;

        await using var stream = await files[0].OpenReadAsync();
        vm.AddAttachment(files[0].Name, stream);
    }

    private async void OnOpenAttachment(object? sender, RoutedEventArgs e)
    {
        if (DataContext is not DocumentationDialogViewModel vm) return;
        if (sender is not Button { Tag: AttachmentItem item }) return;

        using var source = vm.OpenAttachment(item);
        if (source is null) return;

        var file = await StorageProvider.SaveFilePickerAsync(new FilePickerSaveOptions
        {
            Title = "Anhang speichern unter", SuggestedFileName = item.FileName,
        });
        if (file is null) return;

        await using var target = await file.OpenWriteAsync();
        await source.CopyToAsync(target);
    }
}