using NUnit.Framework;
using ProjectM.Simulation;
using Unity.Mathematics;

namespace ProjectM.Tests
{
    /// <summary>
    /// MC-4 — pure cone hit-test (<see cref="MeleeConeMath.InCone"/>): the planar XZ range gate + the
    /// dot(bearing, facing) &gt;= cos(halfAngle) cone gate, plus the coincident / zero-facing / non-positive-range
    /// guards. Shares the exact predicate AutoTarget uses, but as a per-candidate boolean for the collect-all cleave.
    /// </summary>
    public class MeleeConeMathTests
    {
        const float Cos60 = 0.5f; // cos(60deg): half-angle 60 -> 120deg full cone

        [Test]
        public void In_Range_And_Straight_Ahead_Hits()
        {
            Assert.IsTrue(MeleeConeMath.InCone(float3.zero, new float2(0, 1), 3f, Cos60, new float3(0, 0, 2)));
        }

        [Test]
        public void Out_Of_Range_Misses()
        {
            Assert.IsFalse(MeleeConeMath.InCone(float3.zero, new float2(0, 1), 3f, Cos60, new float3(0, 0, 4)));
        }

        [Test]
        public void At_90_Degrees_Outside_Cone_Misses()
        {
            // bearing +X vs facing +Z: dot = 0 < cos60 (0.5) -> outside the cone.
            Assert.IsFalse(MeleeConeMath.InCone(float3.zero, new float2(0, 1), 3f, Cos60, new float3(2, 0, 0)));
        }

        [Test]
        public void At_45_Degrees_Inside_Cone_Hits()
        {
            // bearing ~45deg: dot ~0.707 > 0.5 -> inside.
            Assert.IsTrue(MeleeConeMath.InCone(float3.zero, new float2(0, 1), 5f, Cos60, new float3(2, 0, 2)));
        }

        [Test]
        public void Behind_The_Player_Misses()
        {
            Assert.IsFalse(MeleeConeMath.InCone(float3.zero, new float2(0, 1), 5f, Cos60, new float3(0, 0, -2)));
        }

        [Test]
        public void Coincident_Target_Excluded()
        {
            Assert.IsFalse(MeleeConeMath.InCone(float3.zero, new float2(0, 1), 3f, Cos60, float3.zero));
        }

        [Test]
        public void Zero_Facing_Or_NonPositive_Range_Misses()
        {
            Assert.IsFalse(MeleeConeMath.InCone(float3.zero, float2.zero, 3f, Cos60, new float3(0, 0, 2)), "zero facing -> miss");
            Assert.IsFalse(MeleeConeMath.InCone(float3.zero, new float2(0, 1), 0f, Cos60, new float3(0, 0, 1)), "range 0 -> miss");
        }

        [Test]
        public void Uses_Planar_XZ_And_Ignores_Y()
        {
            // straight ahead in XZ but far in Y: still a hit (Y ignored, top-down).
            Assert.IsTrue(MeleeConeMath.InCone(float3.zero, new float2(0, 1), 3f, Cos60, new float3(0, 5, 2)));
        }
    }
}