using OpenTK.Mathematics;
using VoxelEngine.Rendering;
using Xunit;

namespace VoxelEngine.Tests;

public class CameraTests
{
    [Fact]
    public void DefaultFront_PointsTowardNegativeZ()
    {
        var camera = new Camera(Vector3.Zero, 16f / 9f);

        Assert.Equal(0f, camera.Front.X, 3);
        Assert.Equal(0f, camera.Front.Y, 3);
        Assert.Equal(-1f, camera.Front.Z, 3);
    }

    [Fact]
    public void Move_TranslatesPosition()
    {
        var camera = new Camera(Vector3.Zero, 1f);
        camera.Move(new Vector3(1f, 2f, 3f));
        Assert.Equal(new Vector3(1f, 2f, 3f), camera.Position);
    }

    [Fact]
    public void AddRotation_ClampsPitchTo89Degrees()
    {
        var camera = new Camera(Vector3.Zero, 1f);
        camera.AddRotation(0f, 200f); // try to over-rotate up
        Assert.True(camera.Pitch <= 89.0001f);
        camera.AddRotation(0f, -400f);
        Assert.True(camera.Pitch >= -89.0001f);
    }

    [Fact]
    public void ProjectionMatrix_IsNotIdentity()
    {
        var camera = new Camera(Vector3.Zero, 1.5f);
        Assert.NotEqual(Matrix4.Identity, camera.GetProjectionMatrix());
    }
}