using System.Collections.Generic;
using System.Numerics;
using AcDream.Core.Physics;
using Xunit;

namespace AcDream.Core.Tests.Physics;

public class CellTransitAddAllOutsideCellsTests
{
    [Fact]
    public void SphereWellInsideCell_AddsOneCell()
    {
        // A6.P4 (2026-05-24): coords are LANDBLOCK-LOCAL (X/Y in [0, 192]).
        // Player at landblock-local (12, 12, 0) → cell (0,0) in landblock 0xA9B40000.
        // Pre-fix this test passed world coords (32460, 34572) and the function
        // subtracted lbXf=32448 to get local 12. Post-fix the function expects
        // landblock-local directly.
        var candidates = new HashSet<uint>();
        CellTransit.AddAllOutsideCells(
            worldSphereCenter: new Vector3(12f, 12f, 0f),
            sphereRadius: 0.5f,
            currentCellId: 0xA9B40001u,
            candidates);

        Assert.Single(candidates);
        Assert.Contains(0xA9B40001u, candidates);
    }

    [Fact]
    public void SphereAtCellEastBoundary_AddsTwoCells()
    {
        // A6.P4 (2026-05-24): landblock-local coords. Player at (23.6, 12, 0)
        // — near +X edge of cell (0,0). Sphere reaches to local X = 23.6 + 0.5
        // = 24.1 → cell (1,0) added.
        var candidates = new HashSet<uint>();
        CellTransit.AddAllOutsideCells(
            worldSphereCenter: new Vector3(23.6f, 12f, 0f),
            sphereRadius: 0.5f,
            currentCellId: 0xA9B40001u,
            candidates);

        Assert.Equal(2, candidates.Count);
        Assert.Contains(0xA9B40001u, candidates);
        // Cell (1,0): low-16 id = 1 * 8 + 0 + 1 = 9 → 0x0009.
        Assert.Contains(0xA9B40009u, candidates);
    }
}