using System.Collections.Generic;
using ProjectM.Simulation;
using Unity.Entities;
using Unity.Mathematics;
using Unity.NetCode;
using Unity.Transforms;
using UnityEngine;
using static ProjectM.Client.FeedbackFx;

namespace ProjectM.Client
{
    /// <summary>
    /// Client-only WORLD JUICE for harvesting resource nodes + smashing Blight clutter. A managed presentation
    /// system (SystemBase, main thread, NO Burst) in <see cref="PresentationSystemGroup"/> that REACTS to
    /// replicated state — it never runs simulation. Each frame it edge-detects every node/clutter ghost's
    /// replicated <c>Remaining</c>: a decrease spawns a small tinted chip burst + soft SFX; a despawn (the server
    /// destroyed it — depletion or shatter) spawns a clear burst + SFX, and clutter adds a camera punch (the
    /// "carve through the frontier" smash). A PROXIMITY GATE suppresses the prune VFX unless the despawned
    /// entity's last position was near the local player, so the region-transit despawn storm at +1000 X stays
    /// silent off-camera (GhostRelevancy drops every expedition ghost at once when the player walks home).
    /// Procedural particles + procedural SFX (mirrors CombatFeedbackSystem; self-contained); knobs live in
    /// <see cref="WorldFeelConfig"/>. Never destroys a ghost — GhostDespawnSystem owns despawn; we only OBSERVE.
    /// </summary>
    [WorldSystemFilter(WorldSystemFilterFlags.ClientSimulation)]
    [UpdateInGroup(typeof(PresentationSystemGroup))]
    public partial class WorldFeedbackSystem : SystemBase
    {
        struct Cache { public int Remaining; public float3 Pos; public bool IsClutter; public Color Tint; public byte Variant; }

        readonly Dictionary<Entity, Cache> _cache = new();
        readonly HashSet<Entity> _seen = new();
        readonly List<Entity> _stale = new();

        Transform _fxRoot;
        ParticleSystem _chipFx;
        ParticleSystem _clearFx;
        AudioClip _chipClip;
        AudioClip _clearClip;
        AudioClip _boomClip;
        readonly Dictionary<Entity, GameObject> _fuseRings = new(); // blast-radius discs, one per lit fuse
        Mesh _fuseDiscMesh;
        Material _fuseMat;

        protected override void OnCreate()
        {
            _chipClip = MakeClip("harvest_chip", 900f, 1400f, 0.06f, 0.30f);
            _clearClip = MakeClip("clutter_clear", 420f, 90f, 0.22f, 0.50f);
            _boomClip = MakeClip("barrel_boom", 140f, 40f, 0.45f, 0.65f, noise: true, decay: 6f);
        }

        protected override void OnStartRunning()
        {
            if (_fxRoot != null) return;
            _fxRoot = new GameObject("~WorldFeedbackFX").transform;
            var mat = MakeParticleMaterial();
            _chipFx = MakeBurst(_fxRoot, "HarvestChips", mat, new Color(2.6f, 1.9f, 0.7f), 0.10f, 5f, 0.30f, 256, 0.25f, 0.10f, 0.2f);
            _clearFx = MakeBurst(_fxRoot, "ClutterClear", mat, new Color(3.0f, 1.1f, 0.25f), 0.16f, 7f, 0.45f, 512, 0.25f, 0.10f, 0.2f);
            // Blast-radius disc for lit barrel fuses (operator 07-10: the radius was unreadable) — a flat ground
            // disc at EXACTLY Tuning.BarrelExplodeRadius, pulsing via the shared material's alpha.
            _fuseMat = MakeParticleMaterial();
            _fuseMat.name = "BarrelFuseDisc";
            _fuseMat.color = new Color(2.8f, 0.55f, 0.18f, 0.35f);
            _fuseDiscMesh = BuildDisc(32);
        }

        protected override void OnDestroy()
        {
            if (_fxRoot != null) Object.Destroy(_fxRoot.gameObject); // fuse rings are children -> die with it
            if (_fuseMat != null) Object.Destroy(_fuseMat);
            if (_fuseDiscMesh != null) Object.Destroy(_fuseDiscMesh);
            // Procedural clips are NOT children of _fxRoot — see FeedbackFx.DestroyClip.
            FeedbackFx.DestroyClip(ref _chipClip);
            FeedbackFx.DestroyClip(ref _clearClip);
            FeedbackFx.DestroyClip(ref _boomClip);
        }

        protected override void OnUpdate()
        {
            if (!WorldFeelConfig.Enabled) { _cache.Clear(); return; }

            // Complete predicted/interpolation jobs writing these before the main-thread reads.
            EntityManager.CompleteDependencyBeforeRO<ResourceNode>();
            EntityManager.CompleteDependencyBeforeRO<BlightClutter>();
            EntityManager.CompleteDependencyBeforeRO<LocalTransform>();

            // Local player position (for the proximity gate).
            bool haveLocal = false;
            float3 localPos = default;
            foreach (var xf in SystemAPI.Query<RefRO<LocalTransform>>().WithAll<GhostOwnerIsLocal, PlayerTag>())
            {
                localPos = xf.ValueRO.Position;
                haveLocal = true;
            }

            _seen.Clear();

            // Resource nodes — chip on depletion.
            foreach (var (node, xf, e) in
                     SystemAPI.Query<RefRO<ResourceNode>, RefRO<LocalTransform>>().WithEntityAccess())
            {
                _seen.Add(e);
                Observe(e, node.ValueRO.Remaining, xf.ValueRO.Position, false, TintForResource(node.ValueRO.ResourceId), 0, haveLocal && math.distancesq(xf.ValueRO.Position, localPos) <= WorldFeelConfig.ProximityRange * WorldFeelConfig.ProximityRange);
            }

            // Blight clutter — chip on damage.
            foreach (var (clutter, xf, e) in
                     SystemAPI.Query<RefRO<BlightClutter>, RefRO<LocalTransform>>().WithEntityAccess())
            {
                _seen.Add(e);
                Observe(e, clutter.ValueRO.Remaining, xf.ValueRO.Position, true, WorldFeelConfig.WildTint, clutter.ValueRO.Variant, haveLocal && math.distancesq(xf.ValueRO.Position, localPos) <= WorldFeelConfig.ProximityRange * WorldFeelConfig.ProximityRange);
                UpdateFuseRing(e, clutter.ValueRO, xf.ValueRO.Position);
            }

            // blast-radius discs pulse in sync (one shared material)
            if (_fuseRings.Count > 0 && _fuseMat != null)
            {
                float fa = 0.30f + 0.22f * Mathf.Abs(Mathf.Sin(UnityEngine.Time.time * 9f));
                var fc = _fuseMat.color;
                _fuseMat.color = new Color(fc.r, fc.g, fc.b, fa);
            }

            // Prune: a despawn = the server destroyed it (node depleted / clutter shattered). Gate on proximity so
            // a region-transit despawn storm (every expedition ghost dropped at once, far at +1000 X) stays silent.
            if (_cache.Count != _seen.Count)
            {
                _stale.Clear();
                foreach (var kv in _cache)
                    if (!_seen.Contains(kv.Key)) _stale.Add(kv.Key);

                float rangeSq = WorldFeelConfig.ProximityRange * WorldFeelConfig.ProximityRange;
                for (int i = 0; i < _stale.Count; i++)
                {
                    var c = _cache[_stale[i]];
                    if (haveLocal && math.distancesq(c.Pos, localPos) <= rangeSq)
                    {
                        if (c.IsClutter && c.Variant == 3 && c.Remaining <= 0)
                        {
                            // EXPLOSIVE detonation: only a hit-popped barrel reaches despawn with a cached
                            // Remaining of 0 (a teardown despawn still carries Remaining>0) — the review-hardened
                            // boom-vs-puff split, so portal-advance teardowns can never fire false booms.
                            EmitTinted(_clearFx, (Vector3)c.Pos + Vector3.up * 0.6f, WorldFeelConfig.ClearBurstCount * 4, new Color(3.4f, 1.4f, 0.3f));
                            DynamicLightSystem.RequestFlash((Vector3)c.Pos, new Color(1f, 0.62f, 0.25f), 1.6f);
                            PlayClip(_boomClip, (Vector3)c.Pos, 0.8f);
                            PrototypeCameraRig.PunchFov(WorldFeelConfig.ClearFovKick * 2.2f, 90f);
                            PrototypeCameraRig.AddShake(WorldFeelConfig.ClearShake * 2.5f);
                            ScorchDecalSystem.RequestScorch((Vector3)c.Pos, Tuning.BarrelExplodeRadius); // bundle 2: charred ground mark at the boom
                        }
                        else
                        {
                            EmitTinted(_clearFx, (Vector3)c.Pos + Vector3.up * 0.6f, WorldFeelConfig.ClearBurstCount, c.Tint);
                            PlayClip(_clearClip, (Vector3)c.Pos, WorldFeelConfig.ClearSfxVolume);
                            if (c.IsClutter)
                            {
                                PrototypeCameraRig.PunchFov(WorldFeelConfig.ClearFovKick, 90f);
                                PrototypeCameraRig.AddShake(WorldFeelConfig.ClearShake);
                            }
                        }
                    }
                    if (_fuseRings.TryGetValue(_stale[i], out var ring))
                    {
                        if (ring != null) Object.Destroy(ring);
                        _fuseRings.Remove(_stale[i]);
                    }
                    _cache.Remove(_stale[i]);
                }
            }
        }

void Observe(Entity e, int remaining, float3 pos, bool isClutter, Color tint, byte variant, bool nearLocal)
        {
            if (_cache.TryGetValue(e, out var prev) && remaining < prev.Remaining)
            {
                EmitTinted(_chipFx, (Vector3)pos + Vector3.up * 0.6f, WorldFeelConfig.ChipBurstCount, tint);
                PlayClip(_chipClip, (Vector3)pos, WorldFeelConfig.ChipSfxVolume);
                if (nearLocal) // tiny per-hit camera impact, only for harvesting near the local player (not a teammate's far node)
                {
                    if (WorldFeelConfig.ChipFovKick > 0f) PrototypeCameraRig.PunchFov(WorldFeelConfig.ChipFovKick, 90f);
                    if (WorldFeelConfig.ChipShake > 0f) PrototypeCameraRig.AddShake(WorldFeelConfig.ChipShake);
                }
            }
            _cache[e] = new Cache { Remaining = remaining, Pos = pos, IsClutter = isClutter, Tint = tint, Variant = variant };
        }

        // Lit fuse (Variant 3, Remaining 0 on a live barrel) -> a flat ground disc at EXACTLY the detonation
        // radius so the player reads WHERE not to stand. Removed via the prune path (a fused barrel can only
        // despawn — detonation or teardown).
        void UpdateFuseRing(Entity e, BlightClutter clutter, float3 pos)
        {
            if (clutter.Variant != 3 || clutter.Remaining > 0) return;
            if (!_fuseRings.TryGetValue(e, out var go) || go == null)
            {
                go = new GameObject("BarrelBlastRadius");
                go.transform.SetParent(_fxRoot, false);
                var mf = go.AddComponent<MeshFilter>();
                mf.sharedMesh = _fuseDiscMesh;
                var mr = go.AddComponent<MeshRenderer>();
                mr.sharedMaterial = _fuseMat;
                mr.shadowCastingMode = UnityEngine.Rendering.ShadowCastingMode.Off;
                mr.receiveShadows = false;
                go.transform.localScale = new Vector3(Tuning.BarrelExplodeRadius, 1f, Tuning.BarrelExplodeRadius);
                _fuseRings[e] = go;
            }
            go.transform.position = new Vector3(pos.x, 0.06f, pos.z);
        }

        static Color TintForResource(byte resourceId)
        {
            if (resourceId == ResourceId.Ore) return WorldFeelConfig.OreTint;
            if (resourceId == ResourceId.Biomass) return WorldFeelConfig.BiomassTint;
            return WorldFeelConfig.WildTint; // Aether + default
        }

        // ---- procedural particles + SFX (mirrors CombatFeedbackSystem; self-contained) ----










    }
}