using NSubstitute;
using PLib.Desktop.Services;
using PLib.Desktop.ViewModels;
using PLib.Domain.Videos;
using Shouldly;

namespace PLib.Tests.ViewModels;

/// <summary>
/// The card carries its labels so the grid can be narrowed to one without a query per card.
/// </summary>
public sealed class VideoCardLabelTests
{
    [Fact]
    public void Labels_are_only_taken_when_a_caller_says_it_actually_loaded_them()
    {
        var item = Video();
        item.AddLabel(new LibraryLabel("Драма", LabelKind.Tag));

        var card = Card(item);

        // Apply alone is the scan's path, and the scan loads videos without their labels —
        // an empty collection there means "not loaded", not "none".
        card.Apply(item);
        card.LabelIds.ShouldBeEmpty();

        card.ApplyLabels(item.Labels);
        card.LabelIds.Count.ShouldBe(1);
    }

    [Fact]
    public void A_card_is_kept_by_the_filter_only_for_labels_it_carries()
    {
        var mine = new LibraryLabel("Моё", LabelKind.Tag);
        var other = new LibraryLabel("Чужое", LabelKind.Studio);

        var item = Video();
        item.AddLabel(mine);

        var card = Card(item);
        card.ApplyLabels(item.Labels);

        card.HasLabel(mine.Id).ShouldBeTrue();
        card.HasLabel(other.Id).ShouldBeFalse();
    }

    [Fact]
    public void Searching_reaches_the_label_names_as_well_as_the_title_and_the_path()
    {
        var item = Video();
        item.AddLabel(new LibraryLabel("Кристофер Нолан", LabelKind.Performer));

        var card = Card(item);
        card.ApplyLabels(item.Labels);

        // Typing a performer's name is a search, not a trip to another tab.
        card.Matches("нолан").ShouldBeTrue();
        card.Matches("clip").ShouldBeTrue();
        card.Matches("чего-то ещё").ShouldBeFalse();
    }

    [Fact]
    public void Reapplying_labels_replaces_them_rather_than_accumulating()
    {
        var item = Video();
        item.AddLabel(new LibraryLabel("Первый", LabelKind.Tag));

        var card = Card(item);
        card.ApplyLabels(item.Labels);

        item.RemoveLabel(item.Labels.Single().Id);
        card.ApplyLabels(item.Labels);

        // A label removed on the media page has to stop narrowing the grid straight away.
        card.LabelIds.ShouldBeEmpty();
        card.LabelText.ShouldBeNull();
    }

    private static VideoItem Video() =>
        new(@"C:\videos\clip.mp4", "clip", 1_000, DateTimeOffset.UnixEpoch);

    private static VideoCardViewModel Card(VideoItem item) =>
        new(item, Substitute.For<ISystemShell>(), _ => { });
}