using NUnit.Framework;
using ProjectM.Simulation;

namespace ProjectM.Tests
{
    /// <summary>
    /// Pure-function tests for <see cref="ZoneEnemyMath"/> (no ECS world): the deterministic, save-reproducible
    /// wave size. Pins the lower bound and the per-epoch ramp.
    ///
    /// 2026-08-07 audit purge: the IsChargerSlot / weighted-composition tests are gone with the 4-kind MixBands
    /// model. They were green the whole time while the behaviour they certified could not execute — no prefab
    /// carried ChargerAuthoring, so every weighted slot resolved to Grunt at runtime. That false confidence is
    /// exactly what the audit flagged. Recover them from git alongside MixBands if the model returns.
    /// </summary>
    public class ZoneEnemyMathTests
    {
        [Test]
        public void WaveSize_LowerBoundedAtOne()
        {
            Assert.AreEqual(1, ZoneEnemyMath.WaveSize(0, 0), "an occupied arena always has at least one enemy");
            Assert.AreEqual(1, ZoneEnemyMath.WaveSize(-5, 0), "epoch is floored at 1 internally");
        }

        [Test]
        public void WaveSize_BaselinePlusOnePerEpoch()
        {
            Assert.AreEqual(5, ZoneEnemyMath.WaveSize(1, 5), "epoch 1 == the baked base count");
            Assert.AreEqual(7, ZoneEnemyMath.WaveSize(3, 5), "epoch 3: baseline 5 + (3-1) ramp");
        }

        [Test]
        public void WaveSize_NegativeBaseCount_StillFights()
        {
            Assert.AreEqual(1, ZoneEnemyMath.WaveSize(1, -4), "a mis-authored negative base count still fights");
        }

        [Test]
        public void WaveSize_Deterministic()
        {
            for (int epoch = 1; epoch < 9; epoch++)
                Assert.AreEqual(ZoneEnemyMath.WaveSize(epoch, 5), ZoneEnemyMath.WaveSize(epoch, 5),
                    "same inputs must give the same wave size — a replayed wave is identical");
        }
    }
}