using System.Collections.Generic;
using System.Linq;
using System.Numerics;
using AcDream.App.Rendering;
using Xunit;

namespace AcDream.App.Tests.Rendering;

public class IndoorDrawPlanTests
{
    private static ViewPolygon Quad() => new(new[]
    { new Vector2(-1, -1), new Vector2(1, -1), new Vector2(1, 1), new Vector2(-1, 1) });

    private static PortalVisibilityFrame FrameWith(params uint[] orderedCells)
    {
        var f = new PortalVisibilityFrame();
        foreach (var id in orderedCells)
        {
            f.OrderedVisibleCells.Add(id);
            var v = new CellView(); v.Add(Quad());
            f.CellViews[id] = v;
        }
        return f;
    }

    [Fact]
    public void ShellPass_IncludesEveryVisibleCell_NoFilter()
    {
        // The grey bug: a cell in OrderedVisibleCells must NEVER be dropped from the
        // shell pass. (Old code dropped cells lacking a ClipFrameAssembler slot.)
        var f = FrameWith(0x01, 0x02, 0x03);
        var plan = IndoorDrawPlan.ShellPass(f);
        Assert.Equal(new uint[] { 0x03, 0x02, 0x01 }, plan.Select(e => e.CellId).ToArray()); // reverse = far→near
        Assert.All(plan, e => Assert.NotEmpty(e.Slices));
    }

    [Fact]
    public void ShellPass_ExcludesEmptyViewCells()
    {
        var f = FrameWith(0x01);
        f.OrderedVisibleCells.Add(0x02);     // present in the list…
        f.CellViews[0x02] = new CellView();  // …but empty view → not drawable
        var plan = IndoorDrawPlan.ShellPass(f);
        Assert.Equal(new uint[] { 0x01 }, plan.Select(e => e.CellId).ToArray());
    }
}