using NUnit.Framework;
using ProjectM.Server;
using ProjectM.Simulation;
using Unity.Core;
using Unity.Entities;
using Unity.NetCode;
using Unity.Transforms;

namespace ProjectM.Tests
{
    /// <summary>
    /// Plain-Entities EditMode tests for the server-only <see cref="WaveSystem"/> (Husk wave/threat director).
    /// A bare world is seeded with NetworkTime + CycleState singletons and a director entity carrying
    /// WaveDirector + WaveState + a WaveEnemyPrefab buffer (whose prefab is a real <c>Prefab</c>-tagged entity so
    /// it is excluded from the alive-Husk query and Instantiate yields plain Husk instances). Pins: a due Lull
    /// starts the next (escalating) wave; Spawning emits one Husk per interval; the director is gated off outside
    /// Defend; a fully-spawned, cleared wave returns to Lull.
    /// </summary>
    public class WaveSystemTests
    {
        static (World world, SimulationSystemGroup group) MakeWorld(string name, uint serverTick, byte cyclePhase)
        {
            var world = new World(name);
            var group = world.GetOrCreateSystemManaged<SimulationSystemGroup>();
            group.AddSystemToUpdateList(world.GetOrCreateSystem<WaveSystem>());
            group.SortSystems();
            world.SetTime(new TimeData(elapsedTime: 0f, deltaTime: 1f / 60f));
            var em = world.EntityManager;
            var nt = em.CreateEntity(typeof(NetworkTime));
            em.SetComponentData(nt, new NetworkTime { ServerTick = new NetworkTick(serverTick) });
            var cyc = em.CreateEntity(typeof(CycleState));
            em.SetComponentData(cyc, new CycleState { Phase = cyclePhase });
            return (world, group);
        }

        static Entity MakeHuskPrefab(EntityManager em)
        {
            var e = em.CreateEntity(typeof(LocalTransform), typeof(EnemyTag));
            em.AddComponent<Prefab>(e); // real prefab: excluded from EnemyTag queries; Instantiate strips the tag
            return e;
        }

        static Entity MakeDirector(EntityManager em, Entity huskPrefab, byte phase, int waveNumber,
            uint nextActionTick, int remainingToSpawn, int spawnCounter)
        {
            var e = em.CreateEntity(typeof(WaveDirector), typeof(WaveState));
            em.SetComponentData(e, new WaveDirector
            {
                RingRadius = 10f, RingSlots = 12, BaseCount = 3, CountPerWave = 2,
                SpawnIntervalTicks = 10, LullTicks = 5,
            });
            em.SetComponentData(e, new WaveState
            {
                Phase = phase, WaveNumber = waveNumber, NextActionTick = nextActionTick,
                RemainingToSpawn = remainingToSpawn, SpawnCounter = spawnCounter,
            });
            var buf = em.AddBuffer<WaveEnemyPrefab>(e);
            buf.Add(new WaveEnemyPrefab { Prefab = huskPrefab });
            return e;
        }

        static int HuskCount(EntityManager em)
        {
            using var q = em.CreateEntityQuery(typeof(EnemyTag));
            return q.CalculateEntityCount();
        }

        [Test]
        public void Due_Lull_Starts_Wave_With_Escalating_Count()
        {
            var (world, group) = MakeWorld("WaveLullStart", serverTick: 100, cyclePhase: CyclePhase.Defend);
            using (world)
            {
                var em = world.EntityManager;
                var prefab = MakeHuskPrefab(em);
                var dir = MakeDirector(em, prefab, WavePhase.Lull, waveNumber: 0, nextActionTick: 100, remainingToSpawn: 0, spawnCounter: 0);

                group.Update();

                var w = em.GetComponentData<WaveState>(dir);
                Assert.AreEqual(WavePhase.Spawning, w.Phase, "A due lull starts spawning.");
                Assert.AreEqual(1, w.WaveNumber, "Wave number advances.");
                Assert.AreEqual(3, w.RemainingToSpawn, "Wave 1 count = BaseCount + (1-1)*CountPerWave = 3.");
                Assert.AreEqual(0, HuskCount(em), "No Husk is spawned on the lull->spawning transition tick itself.");
            }
        }

        [Test]
        public void Spawning_Emits_One_Husk_And_Decrements_Remaining()
        {
            var (world, group) = MakeWorld("WaveSpawnOne", serverTick: 100, cyclePhase: CyclePhase.Defend);
            using (world)
            {
                var em = world.EntityManager;
                var prefab = MakeHuskPrefab(em);
                var dir = MakeDirector(em, prefab, WavePhase.Spawning, waveNumber: 1, nextActionTick: 100, remainingToSpawn: 3, spawnCounter: 0);

                group.Update();

                Assert.AreEqual(1, HuskCount(em), "One Husk spawns this interval.");
                var w = em.GetComponentData<WaveState>(dir);
                Assert.AreEqual(2, w.RemainingToSpawn, "RemainingToSpawn decrements.");
                Assert.AreEqual(1, w.SpawnCounter, "SpawnCounter advances (drives ring slot + round-robin).");
            }
        }

        [Test]
        public void Director_Is_Gated_Off_Outside_Defend()
        {
            var (world, group) = MakeWorld("WaveGated", serverTick: 100, cyclePhase: CyclePhase.Expedition);
            using (world)
            {
                var em = world.EntityManager;
                var prefab = MakeHuskPrefab(em);
                var dir = MakeDirector(em, prefab, WavePhase.Lull, waveNumber: 0, nextActionTick: 100, remainingToSpawn: 0, spawnCounter: 0);

                group.Update();

                var w = em.GetComponentData<WaveState>(dir);
                Assert.AreEqual(WavePhase.Lull, w.Phase, "Outside Defend the director does not run.");
                Assert.AreEqual(0, w.WaveNumber, "Wave number stays put outside Defend.");
            }
        }

        [Test]
        public void Fully_Spawned_Cleared_Wave_Returns_To_Lull()
        {
            var (world, group) = MakeWorld("WaveCleared", serverTick: 100, cyclePhase: CyclePhase.Defend);
            using (world)
            {
                var em = world.EntityManager;
                var prefab = MakeHuskPrefab(em);
                var dir = MakeDirector(em, prefab, WavePhase.Spawning, waveNumber: 1, nextActionTick: 100, remainingToSpawn: 0, spawnCounter: 3);

                group.Update();

                Assert.AreEqual(WavePhase.Lull, em.GetComponentData<WaveState>(dir).Phase,
                    "A fully-spawned wave with no live Husks returns to Lull.");
            }
        }
    }
}