using AcDream.App.Studio;
using AcDream.App.UI;
using AcDream.App.UI.Layout;
using DatReaderWriter;
using DatReaderWriter.Options;

namespace AcDream.App.Tests.Studio;

/// <summary>
/// Unit tests for <see cref="LayoutSource"/>. The dat-backed test skips cleanly
/// when the real dats are not present (CI / dev machines without AC installed).
/// </summary>
public class LayoutSourceTests
{
    private static (uint handle, int width, int height) NoTex(uint _) => (1u, 1, 1);

    /// <summary>Resolve the client dat directory, or null if unavailable (skip the test).</summary>
    private static string? ResolveDatDir()
    {
        var fromEnv = Environment.GetEnvironmentVariable("ACDREAM_DAT_DIR");
        if (!string.IsNullOrWhiteSpace(fromEnv) && Directory.Exists(fromEnv))
            return fromEnv;
        var def = Path.Combine(
            Environment.GetFolderPath(Environment.SpecialFolder.UserProfile),
            "Documents", "Asheron's Call");
        return Directory.Exists(def) ? def : null;
    }

    /// <summary>
    /// Load the vitals LayoutDesc (0x2100006C) from the real dats and verify
    /// that LayoutSource returns a non-null root with the layout id findable.
    /// Skips when the dats are unavailable.
    ///
    /// Note: the spec asserts FindElement(0x2100006Cu) — that is the layout dat
    /// id, not an element id in the widget tree. The actual vitals root element id
    /// is 0x100005F9 (confirmed from vitals_2100006C.json fixture). We assert
    /// FindElement(0x100005F9) here which verifies the same integration path: the
    /// layout was successfully loaded and the element dict was populated.
    /// </summary>
    [Fact]
    public void LoadsDatLayout_byId()
    {
        var dir = ResolveDatDir();
        if (dir is null)
            return; // Skip: dats not available on this machine / CI.

        using var dats = new DatCollection(dir, DatAccessType.Read);

        var src  = new LayoutSource(dats, NoTex, datFont: null);
        var root = src.Load(new StudioOptions(dir, 0x2100006Cu, null));

        // root must be non-null: Import found the LayoutDesc and built the tree.
        Assert.NotNull(root);
        Assert.NotNull(src.CurrentLayout);
        // The vitals root element id is 0x100005F9 (layout dat id 0x2100006C ≠ element id).
        // Asserting FindElement verifies the byId dict was populated by the importer.
        Assert.NotNull(src.CurrentLayout!.FindElement(0x100005F9u));
        Assert.Equal(LayoutSourceKind.DatLayout, src.Kind);
    }
}