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 tests for <see cref="DashTrailDamageSystem"/> (Phase 1.7 Blade Dash). A dashing player with the
    /// boon damages a nearby enemy ONCE per dash (StartTick-keyed dedup survives a re-tick); a fresh dash hits again;
    /// no boon → no damage.
    /// </summary>
    public class DashTrailDamageSystemTests
    {
        static (World world, SimulationSystemGroup group, EntityManager em) MakeWorld(uint tick)
        {
            var world = new World("DashTrailTest");
            var group = world.GetOrCreateSystemManaged<SimulationSystemGroup>();
            group.AddSystemToUpdateList(world.GetOrCreateSystem<DashTrailDamageSystem>());
            group.SortSystems();
            world.SetTime(new TimeData(elapsedTime: 0f, deltaTime: 1f / 60f));
            var em = world.EntityManager;
            em.SetComponentData(em.CreateEntity(typeof(NetworkTime)), new NetworkTime { ServerTick = new NetworkTick(tick) });
            return (world, group, em);
        }

        static void SetTick(EntityManager em, uint tick)
        {
            using var q = em.CreateEntityQuery(typeof(NetworkTime));
            em.SetComponentData(q.GetSingletonEntity(), new NetworkTime { ServerTick = new NetworkTick(tick) });
        }

        static Entity MakeDasher(EntityManager em, byte flags, uint startTick, uint iframeUntil)
        {
            var e = em.CreateEntity(typeof(PlayerTag), typeof(GhostOwner), typeof(BoonEffects), typeof(DashTrailState));
            em.AddComponentData(e, LocalTransform.FromPosition(new float3(0f, 0f, 0f)));
            em.AddComponentData(e, new DashState { Dir = new float2(1f, 0f), StartTick = startTick, IFrameUntilTick = iframeUntil, RecoverUntilTick = iframeUntil + 9 });
            em.AddComponent<Simulate>(e); // enabled by default
            em.SetComponentData(e, new GhostOwner { NetworkId = 1 });
            em.SetComponentData(e, new BoonEffects { Flags = flags });
            return e;
        }

        static Entity MakeEnemy(EntityManager em, float3 pos)
        {
            var e = em.CreateEntity(typeof(EnemyTag));
            em.AddComponentData(e, LocalTransform.FromPosition(pos));
            em.AddComponentData(e, new HitRadius { Value = 0.5f });
            em.AddComponentData(e, new Health { Current = 60f, Max = 60f });
            em.AddBuffer<DamageEvent>(e);
            return e;
        }

        [Test]
        public void BladeDash_DamagesNearbyEnemy_OncePerDash_ReHitsOnNextDash()
        {
            var (world, group, em) = MakeWorld(100);
            using (world)
            {
            var player = MakeDasher(em, BoonFlag.DashTrail, startTick: 100, iframeUntil: 112);
            var enemy = MakeEnemy(em, new float3(1f, 0f, 0f)); // within 1.6 + 0.5

            group.Update(); // tick 100, dashing
            Assert.AreEqual(1, em.GetBuffer<DamageEvent>(enemy).Length, "enemy in the dash path takes one hit");

            group.Update(); // same tick + same StartTick -> dedup, no second hit
            Assert.AreEqual(1, em.GetBuffer<DamageEvent>(enemy).Length, "no re-hit within the same dash");

            // A fresh dash (new StartTick) resets the dedup set -> the enemy can be hit again.
            SetTick(em, 130);
            em.SetComponentData(player, new DashState { Dir = new float2(1f, 0f), StartTick = 130, IFrameUntilTick = 142, RecoverUntilTick = 151 });
            group.Update();
            Assert.AreEqual(2, em.GetBuffer<DamageEvent>(enemy).Length, "a fresh dash hits the enemy again");
            }
        }

        [Test]
        public void NoBoon_NoDamage()
        {
            var (world, group, em) = MakeWorld(100);
            using (world)
            {
            MakeDasher(em, flags: 0, startTick: 100, iframeUntil: 112); // no DashTrail flag
            var enemy = MakeEnemy(em, new float3(1f, 0f, 0f));
            group.Update();
            Assert.AreEqual(0, em.GetBuffer<DamageEvent>(enemy).Length, "no Blade Dash boon -> no trail damage");
            }
        }
    }
}