namespace AcDream.App.Tests.Runtime;

public sealed class RuntimeInventoryOwnershipTests
{
    [Fact]
    public void ProductionConstructsOnlyTheRuntimeInventoryOwner()
    {
        string source = ReadSource("Rendering", "GameWindow.cs");

        Assert.Contains(
            "_runtimeInventory = new RuntimeInventoryState(_runtimeEntityObjects);",
            source,
            StringComparison.Ordinal);
        Assert.DoesNotContain(
            "new AcDream.Core.Items.ItemManaState",
            source,
            StringComparison.Ordinal);
        Assert.DoesNotContain(
            "new DesiredComponentSnapshotState",
            source,
            StringComparison.Ordinal);
        Assert.DoesNotContain(
            "new ShortcutSnapshotState",
            source,
            StringComparison.Ordinal);
        Assert.DoesNotContain(
            "new AcDream.Core.Items.ExternalContainerState",
            source,
            StringComparison.Ordinal);
        Assert.DoesNotContain(
            "DesiredComponentState",
            source,
            StringComparison.Ordinal);
    }

    [Fact]
    public void UiSessionAndShutdownBorrowTheExactRuntimeOwner()
    {
        string ui = ReadSource(
            "Composition",
            "InteractionRetainedUiComposition.cs");
        string session = ReadSource("Net", "LiveSessionRuntimeFactory.cs");
        string shutdown = ReadSource("Rendering", "GameWindowLifetime.cs");

        Assert.Contains(
            "transactions: d.Inventory.Transactions",
            ui,
            StringComparison.Ordinal);
        Assert.Contains(
            "OnShortcuts: _domain.Inventory.Shortcuts.Replace",
            session,
            StringComparison.Ordinal);
        Assert.Contains(
            "_domain.Inventory.Transactions.CompleteUse(error)",
            session,
            StringComparison.Ordinal);
        Assert.DoesNotContain(
            "_domain.Inventory.DesiredComponents",
            session,
            StringComparison.Ordinal);
        AssertAppearsInOrder(
            shutdown,
            "\"runtime inventory state\"",
            "\"runtime entity/object lifetime\"");
    }

    private static string ReadSource(params string[] relative)
    {
        string root = FindRepositoryRoot();
        return File.ReadAllText(Path.Combine(
            [root, "src", "AcDream.App", .. relative]));
    }

    private static string FindRepositoryRoot()
    {
        var current = new DirectoryInfo(AppContext.BaseDirectory);
        while (current is not null)
        {
            if (File.Exists(Path.Combine(current.FullName, "AcDream.slnx")))
                return current.FullName;
            current = current.Parent;
        }
        throw new DirectoryNotFoundException("AcDream.slnx was not found.");
    }

    private static void AssertAppearsInOrder(
        string source,
        params string[] fragments)
    {
        int cursor = 0;
        foreach (string fragment in fragments)
        {
            int index = source.IndexOf(
                fragment,
                cursor,
                StringComparison.Ordinal);
            Assert.True(index >= 0, $"Missing source fragment: {fragment}");
            cursor = index + fragment.Length;
        }
    }
}