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

namespace ProjectM.Tests
{
    /// <summary>
    /// Plain-Entities EditMode tests for the server-only <see cref="PlayerRespawnSystem"/> — the authoritative
    /// death→respawn timer. A bare world is seeded with NetworkTime + PlayerSpawner singletons and a player
    /// (Health, RespawnState, RespawnInvuln, LocalTransform, GhostOwner, EffectiveCharacterStats, PlayerTag).
    /// Pins: a newly-dead player schedules a respawn tick; a due tick refills health + repositions + grants
    /// invuln + clears the schedule; an alive player clears any stale pending schedule.
    /// </summary>
    public class PlayerRespawnSystemTests
    {
        static (World world, SimulationSystemGroup group) MakeWorld(string name, uint serverTick)
        {
            var world = new World(name);
            var group = world.GetOrCreateSystemManaged<SimulationSystemGroup>();
            group.AddSystemToUpdateList(world.GetOrCreateSystem<PlayerRespawnSystem>());
            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 sp = em.CreateEntity(typeof(PlayerSpawner));
            em.SetComponentData(sp, new PlayerSpawner { SpawnPoint = new float3(0, 1, 0), SpawnRingRadius = 10f, RingSlots = 4 });
            return (world, group);
        }

        static Entity MakePlayer(EntityManager em, float health, float maxHealth, uint respawnTick,
            int delayTicks, int invulnTicks, float3 pos, int networkId)
        {
            var e = em.CreateEntity();
            em.AddComponentData(e, new Health { Current = health, Max = maxHealth });
            em.AddComponentData(e, new RespawnState { RespawnTick = respawnTick, DelayTicks = delayTicks, InvulnTicks = invulnTicks });
            em.AddComponentData(e, new RespawnInvuln { UntilTick = 0 });
            em.AddComponentData(e, LocalTransform.FromPosition(pos));
            em.AddComponentData(e, new GhostOwner { NetworkId = networkId });
            em.AddComponentData(e, new EffectiveCharacterStats { MaxHealth = maxHealth });
            em.AddComponent<PlayerTag>(e);
            return e;
        }

        [Test]
        public void Newly_Dead_Player_Schedules_Respawn_Tick()
        {
            var (world, group) = MakeWorld("RespawnSchedule", serverTick: 200);
            using (world)
            {
                var em = world.EntityManager;
                var player = MakePlayer(em, health: 0f, maxHealth: 100f, respawnTick: 0,
                    delayTicks: 60, invulnTicks: 120, pos: new float3(5, 1, 5), networkId: 1);

                group.Update();

                Assert.AreEqual(RespawnMath.RespawnTick(200, 60), em.GetComponentData<RespawnState>(player).RespawnTick,
                    "A newly-dead player schedules its respawn tick (now + delay).");
                Assert.AreEqual(0f, em.GetComponentData<Health>(player).Current, 1e-4f, "Still down until the tick is due.");
            }
        }

        [Test]
        public void Due_Respawn_Restores_Health_Repositions_And_Grants_Invuln()
        {
            var (world, group) = MakeWorld("RespawnRecover", serverTick: 200);
            using (world)
            {
                var em = world.EntityManager;
                var player = MakePlayer(em, health: 0f, maxHealth: 100f, respawnTick: 160,
                    delayTicks: 60, invulnTicks: 120, pos: new float3(999, 1, 999), networkId: 1);

                group.Update();

                Assert.AreEqual(100f, em.GetComponentData<Health>(player).Current, 1e-4f, "Health refills to the effective max.");
                Assert.AreEqual(320u, em.GetComponentData<RespawnInvuln>(player).UntilTick,
                    "Post-respawn invulnerability is granted until now + InvulnTicks (200 + 120).");
                Assert.AreEqual(0u, em.GetComponentData<RespawnState>(player).RespawnTick, "The respawn schedule is cleared on recovery.");
                Assert.Less(em.GetComponentData<LocalTransform>(player).Position.x, 100f,
                    "The player is teleported from its death spot back to the base spawn ring.");
            }
        }

        [Test]
        public void Alive_Player_Clears_Stale_Pending_Respawn()
        {
            var (world, group) = MakeWorld("RespawnAliveClear", serverTick: 200);
            using (world)
            {
                var em = world.EntityManager;
                var player = MakePlayer(em, health: 50f, maxHealth: 100f, respawnTick: 999,
                    delayTicks: 60, invulnTicks: 120, pos: new float3(5, 1, 5), networkId: 1);

                group.Update();

                Assert.AreEqual(0u, em.GetComponentData<RespawnState>(player).RespawnTick,
                    "An alive player clears any stale pending respawn schedule.");
                Assert.AreEqual(50f, em.GetComponentData<Health>(player).Current, 1e-4f, "Alive health is untouched.");
            }
        }
    }
}