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

namespace ProjectM.Tests
{
    /// <summary>
    /// Plain-Entities EditMode tests for the server-only <see cref="CyclePhaseSystem"/> — the PLAYER-DRIVEN
    /// run-state director (Calm ↔ Siege). A bare world is seeded with a NetworkTime singleton and a cycle entity
    /// carrying CycleState + CycleRuntime (+ optionally ThreatState / WaveState / GoalProgress). The global phase
    /// is only ever Calm or Siege — being out on an expedition is per-player presence, NOT a global phase — so
    /// these pin: Calm holds with no pending siege; an armed ThreatState.PendingSiegeSize enters Siege and seeds
    /// WaveState's Spawning entry at the EXACT size; a cleared Siege returns to Calm and charges the goal once;
    /// and split co-op presence never produces a non-Calm phase. All timing is wrap-safe NetworkTick math.
    /// </summary>
    public class CyclePhaseSystemTests
    {
        static (World world, SimulationSystemGroup group) MakeWorld(string name, uint serverTick)
        {
            var world = new World(name);
            var group = world.GetOrCreateSystemManaged<SimulationSystemGroup>();
            group.AddSystemToUpdateList(world.GetOrCreateSystem<CyclePhaseSystem>());
            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) });
            return (world, group);
        }

        static Entity MakeCycle(EntityManager em, byte phase, int defendStartWave)
        {
            var e = em.CreateEntity(typeof(CycleState), typeof(CycleRuntime));
            em.SetComponentData(e, new CycleState { Phase = phase, PhaseEndTick = 0u, CycleNumber = 1 });
            em.SetComponentData(e, new CycleRuntime { DefendStartWave = defendStartWave });
            return e;
        }

        static void AddThreat(EntityManager em, Entity cycle, int pendingSiegeSize, uint armTick)
        {
            em.AddComponentData(cycle, new ThreatState { PendingSiegeSize = pendingSiegeSize, ArmTick = armTick });
        }

        static Entity MakeWaveState(EntityManager em, int waveNumber, byte phase, int remainingToSpawn)
        {
            var e = em.CreateEntity(typeof(WaveState));
            em.SetComponentData(e, new WaveState { WaveNumber = waveNumber, Phase = phase, RemainingToSpawn = remainingToSpawn });
            return e;
        }

        [Test]
        public void Calm_Holds_When_No_PendingSiege()
        {
            var (world, group) = MakeWorld("CalmHolds", serverTick: 200);
            using (world)
            {
                var em = world.EntityManager;
                var cycle = MakeCycle(em, CyclePhase.Calm, defendStartWave: 0);
                AddThreat(em, cycle, pendingSiegeSize: 0, armTick: 0);

                group.Update();

                Assert.AreEqual(CyclePhase.Calm, em.GetComponentData<CycleState>(cycle).Phase,
                    "With no pending siege the base stays Calm — no forced timer.");
            }
        }

        [Test]
        public void PendingSiege_Enters_Siege_And_Seeds_WaveState_Spawning_With_Exact_Size()
        {
            var (world, group) = MakeWorld("PendingSiege", serverTick: 200);
            using (world)
            {
                var em = world.EntityManager;
                var cycle = MakeCycle(em, CyclePhase.Calm, defendStartWave: 0);
                AddThreat(em, cycle, pendingSiegeSize: 7, armTick: 0); // armTick 0 => fire immediately
                var wave = MakeWaveState(em, waveNumber: 5, phase: WavePhase.Lull, remainingToSpawn: 0);

                group.Update();

                Assert.AreEqual(CyclePhase.Siege, em.GetComponentData<CycleState>(cycle).Phase,
                    "An armed pending siege enters Siege.");

                var w = em.GetComponentData<WaveState>(wave);
                Assert.AreEqual(WavePhase.Spawning, w.Phase,
                    "WaveState is driven into Spawning (bypassing the Lull escalation recompute).");
                Assert.AreEqual(7, w.RemainingToSpawn,
                    "RemainingToSpawn is the EXACT director-chosen siege size (not the escalation curve).");
                Assert.AreEqual(6, w.WaveNumber, "WaveNumber advances by one for the siege.");

                Assert.AreEqual(5, em.GetComponentData<CycleRuntime>(cycle).DefendStartWave,
                    "DefendStartWave captures the pre-bump wave number.");
                Assert.AreEqual(0, em.GetComponentData<ThreatState>(cycle).PendingSiegeSize,
                    "The pending siege is consumed (zeroed) so it fires exactly once.");
            }
        }

        [Test]
        public void Siege_Exits_To_Calm_On_DefendCleared_And_Charges_Goal_Once()
        {
            var (world, group) = MakeWorld("SiegeClears", serverTick: 200);
            using (world)
            {
                var em = world.EntityManager;
                var cycle = MakeCycle(em, CyclePhase.Siege, defendStartWave: 5);
                em.AddComponentData(cycle, new GoalProgress { Charge = 0, Target = 10 });
                // Wave advanced past the captured start, fully spawned, no Husks alive (none created).
                MakeWaveState(em, waveNumber: 6, phase: WavePhase.Spawning, remainingToSpawn: 0);

                group.Update();

                Assert.AreEqual(CyclePhase.Calm, em.GetComponentData<CycleState>(cycle).Phase,
                    "A cleared siege returns to Calm.");
                Assert.AreEqual(1, em.GetComponentData<GoalProgress>(cycle).Charge,
                    "One goal charge accrues per siege survived (single writer).");
            }
        }

        [Test]
        public void Coop_Split_Presence_Keeps_Global_Phase_Calm()
        {
            var (world, group) = MakeWorld("CoopSplit", serverTick: 200);
            using (world)
            {
                var em = world.EntityManager;
                var cycle = MakeCycle(em, CyclePhase.Calm, defendStartWave: 0);
                AddThreat(em, cycle, pendingSiegeSize: 0, armTick: 0);

                // One player out on expedition, one home — the GLOBAL phase machine must ignore presence.
                var pOut = em.CreateEntity(typeof(RegionTag), typeof(PlayerTag));
                em.SetComponentData(pOut, new RegionTag { Region = RegionId.Expedition });
                var pHome = em.CreateEntity(typeof(RegionTag), typeof(PlayerTag));
                em.SetComponentData(pHome, new RegionTag { Region = RegionId.Base });

                group.Update();

                Assert.AreEqual(CyclePhase.Calm, em.GetComponentData<CycleState>(cycle).Phase,
                    "Split presence (one out, one home) never drives the single global phase — Expedition is per-player.");
            }
        }

        [Test]
        public void WaveNumber_Is_Synced_From_WaveState_For_The_Hud()
        {
            var (world, group) = MakeWorld("WaveSync", serverTick: 200);
            using (world)
            {
                var em = world.EntityManager;
                var cycle = MakeCycle(em, CyclePhase.Siege, defendStartWave: 5);
                MakeWaveState(em, waveNumber: 4, phase: WavePhase.Spawning, remainingToSpawn: 2);

                group.Update();

                Assert.AreEqual(4, em.GetComponentData<CycleState>(cycle).WaveNumber,
                    "CycleState.WaveNumber mirrors the server-only WaveState.WaveNumber for the replicated-state-only HUD.");
            }
        }
    }
}