using System.Collections.ObjectModel;
using Ludarium.Application;
using Ludarium.Domain;

namespace Ludarium.UnitTests;

public sealed class SnapshotComparerTests
{
    [Fact]
    public void ComparisonDistinguishesAddedRemovedMovedChangedAndUnchanged()
    {
        var root = Guid.NewGuid();
        var moved = Guid.NewGuid(); var changed = Guid.NewGuid(); var removed = Guid.NewGuid(); var unchanged = Guid.NewGuid(); var added = Guid.NewGuid();
        var before = Snapshot("before",
            new(root, "old/game.bin", 1, Hash('a'), moved, null),
            new(root, "changed.bin", 1, Hash('b'), changed, null),
            new(root, "removed.bin", 1, Hash('c'), removed, null),
            new(root, "same.bin", 1, Hash('d'), unchanged, null));
        var after = Snapshot("after",
            new(root, "new/game.bin", 1, Hash('a'), moved, null),
            new(root, "changed.bin", 2, Hash('e'), changed, null),
            new(root, "same.bin", 1, Hash('d'), unchanged, null),
            new(root, "added.bin", 1, Hash('f'), added, null));
        var result = new SnapshotComparer().Compare(before, after);
        Assert.Single(result, x => x.Kind == SnapshotChangeKind.Added);
        Assert.Single(result, x => x.Kind == SnapshotChangeKind.Removed);
        Assert.Single(result, x => x.Kind == SnapshotChangeKind.Moved);
        Assert.Single(result, x => x.Kind == SnapshotChangeKind.ContentChanged);
        Assert.Single(result, x => x.Kind == SnapshotChangeKind.Unchanged);
    }

    private static IntegritySnapshot Snapshot(string name, params SnapshotItem[] items) => new(Guid.NewGuid(), name, "1", "test", DateTimeOffset.UtcNow, new ReadOnlyCollection<SnapshotItem>(items));
    private static string Hash(char value) => new(value, 64);
}