using ProjectM.Simulation;
using Rukhanka;                  // FastAnimatorParameter, AnimatorParametersAspect, ParameterValue,
                                 // AnimatorControllerParameterComponent, AnimatorControllerParameterIndexTableComponent,
                                 // RukhankaAnimationSystemGroup
using Unity.Burst;
using Unity.Collections;
using Unity.Entities;
using Unity.Mathematics;
using Unity.NetCode;             // GhostOwnerIsLocal, NetworkTime, NetworkTick
using Unity.Transforms;          // LocalTransform
using Unity.CharacterController; // KinematicCharacterBody

namespace ProjectM.Client
{
    /// <summary>
    /// Client-only animation driver. OBSERVES authoritative/replicated state and writes Rukhanka animator
    /// blend params; never mutates the sim (presentation-only). Runs once/frame in the client/local world,
    /// BEFORE Rukhanka evaluates the controller this frame (same-frame, no 1-tick lag). NOTE: this lands in
    /// SimulationSystemGroup (via UpdateBefore the Rukhanka group, which itself has no UpdateInGroup), a
    /// deliberate, documented exception to the project's "all juice = PresentationSystemGroup" rule -- the
    /// params MUST be set before Rukhanka's same-frame controller eval (see DR-022).
    ///
    /// Drives MoveX/MoveZ/Speed/IsDead from locomotion + IsDead, plus IsAttacking (MC-4) pulsed from the
    /// replicated <see cref="MeleeCombo"/> swing window so the AC_PlayerTopDown MeleeSwing state plays per swing.
    ///
    /// Two paths:
    ///   LOCAL  (owner-predicted, GhostOwnerIsLocal ENABLED): realized CC RelativeVelocity (wall-aware).
    ///   REMOTE (interpolated, GhostOwnerIsLocal DISABLED): KinematicCharacterBody is NOT a [GhostField] and
    ///          the CC processor is owner-only, so RelativeVelocity stays baked-zero on remotes -> derive
    ///          planar velocity from replicated LocalTransform.Position deltas. PlayerFacing.Direction is a
    ///          [GhostField] (valid on remotes); EffectiveCharacterStats.MoveSpeed is derived locally each
    ///          tick by StatRecomputeSystem (present on remotes). MeleeCombo replicates so teammates' swings
    ///          animate too. Cache prevPos per Entity, prune each frame.
    /// </summary>
    [WorldSystemFilter(WorldSystemFilterFlags.LocalSimulation | WorldSystemFilterFlags.ClientSimulation)]
    [UpdateBefore(typeof(RukhankaAnimationSystemGroup))]
    [RequireMatchingQueriesForUpdate]
    public partial class PlayerAnimationDriveSystem : SystemBase
    {
        // Perfect-hash keys, built once (managed string ctor). Names MUST match AC_PlayerTopDown.controller
        // parameter names exactly. Immutable readonly hashes -> domain-reload safe.
        static readonly FastAnimatorParameter k_MoveX       = new FastAnimatorParameter("MoveX");
        static readonly FastAnimatorParameter k_MoveZ       = new FastAnimatorParameter("MoveZ");
        static readonly FastAnimatorParameter k_Speed       = new FastAnimatorParameter("Speed");
        static readonly FastAnimatorParameter k_IsDead      = new FastAnimatorParameter("IsDead");
        static readonly FastAnimatorParameter k_IsAttacking = new FastAnimatorParameter("IsAttacking");
        static readonly FastAnimatorParameter k_IsFiring    = new FastAnimatorParameter("IsFiring");  // Blender-authored A_Fire_OneHand (B7)
        static readonly FastAnimatorParameter k_IsDashing   = new FastAnimatorParameter("IsDashing"); // Blender-authored A_Dash_Lean (local player only - DashState is not replicated)
        static readonly FastAnimatorParameter k_Bank        = new FastAnimatorParameter("Bank");
        static readonly FastAnimatorParameter k_StrideScale = new FastAnimatorParameter("StrideScale"); // 07-16b: Locomotion playback = planarSpeed / TrudgeNaturalSpeed (foot-skate fix)      // 07-16: additive Posture layer — signed facing turn rate, local player only (subtle; not derived for remotes)
        
static readonly FastAnimatorParameter k_ComboStep   = new FastAnimatorParameter("ComboStep"); // replicated MeleeCombo.Step -> per-step swing clips (Swing1/2/3)
        static readonly FastAnimatorParameter k_IsCone      = new FastAnimatorParameter("IsCone");    // ability archetype (replicated AbilityRef + blob): Cone -> two-hand slam, else the shot
        static readonly FastAnimatorParameter k_InCombat    = new FastAnimatorParameter("InCombat");  // 07-18: Menacing01 combat idle -- swing recency (FeelConfig.CombatIdleHoldSec)

        // Ticks after a swing-start that IsAttacking stays true (drives the MeleeSwing state). Kept < the swing lock
        // (MeleeRecoverTicks ~30) so a CHAINED swing re-pulses the bool false->true and re-triggers the Any State
        // transition per hit. ~0.43s @ 60Hz (07-19 heavy retime). Presentation-only.
        const uint k_AttackAnimTicks = PlayerAimSystem.CastFacingTicks; // structurally tied (07-16 review): body-yaw cast-turn and the swing anim pulse must agree

        // Remote prevPos cache (per ghost Entity). Pruned every frame (a vanished remote = a despawn).
        NativeParallelHashMap<Entity, float3> _prevPos;

        // 07-16 banking: previous local-player facing + the smoothed bank value (main-thread state; one entity).
        float2 _prevLocalFacing;
        bool _bankInit;
        float _bankSmoothed;


        protected override void OnCreate()
        {
            _prevPos = new NativeParallelHashMap<Entity, float3>(16, Allocator.Persistent);
        }

        protected override void OnDestroy()
        {
            if (_prevPos.IsCreated) _prevPos.Dispose();
        }

        protected override void OnUpdate()
        {
            float dt = SystemAPI.Time.DeltaTime; // wall-frame delta is correct for presentation
            if (dt < 1e-5f) dt = 1e-5f;

            // Current authoritative tick for the swing-window check (default = invalid -> IsAttacking stays false).
            NetworkTick serverTick = default, interpTick = default;
            if (SystemAPI.TryGetSingleton<NetworkTime>(out var nt))
            {
                serverTick = nt.ServerTick;                                                   // predicted: local owner
                interpTick = nt.InterpolationTick.IsValid ? nt.InterpolationTick : nt.ServerTick; // interpolated: remotes
            }
            // Ability blob for the per-class special read (Cone -> slam anim); default(BlobAssetReference) if absent.
            var abilityBlob = SystemAPI.TryGetSingleton<AbilityDatabase>(out var adbSingleton) ? adbSingleton.Value : default;
            // 07-18 combat idle: swing-recency window (the same wrap-safe SwingActive predicate as the anim pulse, wider). 60Hz sim ticks.
            uint combatIdleTicks = (uint)math.max(1f, FeelConfig.CombatIdleHoldSec * 60f);

            // 07-16 banking: signed facing turn rate -> Bank (-1..1, + = bank right, leaning INTO the turn).
            // Sampled main-thread (a single local player), smoothed so the additive pose eases in and out.
            float bankTarget = 0f;
            foreach (var facingRO in SystemAPI.Query<RefRO<PlayerFacing>>().WithAll<GhostOwnerIsLocal>())
            {
                float2 f = facingRO.ValueRO.Direction;
                if (_bankInit && math.lengthsq(f) > 1e-6f && math.lengthsq(_prevLocalFacing) > 1e-6f)
                {
                    float2 a2 = math.normalize(_prevLocalFacing);
                    float2 b2 = math.normalize(f);
                    float signed = math.atan2(a2.x * b2.y - a2.y * b2.x, math.clamp(math.dot(a2, b2), -1f, 1f));
                    float degPerSec = math.degrees(signed) / dt;
                    bankTarget = math.clamp(-degPerSec / math.max(30f, FeelConfig.BankFullTurnDegPerSec), -1f, 1f);
                }
                _prevLocalFacing = f;
                _bankInit = true;
                break;
            }
            _bankSmoothed = math.lerp(_bankSmoothed, bankTarget, 1f - math.exp(-6f * dt));

            
// --- LOCAL owner (CC velocity) ---
            var localJob = new LocalDriveJob
            {
                moveX = k_MoveX, moveZ = k_MoveZ, speed = k_Speed, isDead = k_IsDead,
                isAttacking = k_IsAttacking, isFiring = k_IsFiring, isDashing = k_IsDashing,
                comboStep = k_ComboStep, isCone = k_IsCone, abilityDb = abilityBlob,
                serverTick = serverTick, attackTicks = k_AttackAnimTicks,
                bank = k_Bank, bankValue = _bankSmoothed,
                inCombat = k_InCombat, combatIdleTicks = combatIdleTicks,
                strideScale = k_StrideScale, trudgeNaturalSpeed = math.max(0.5f, FeelConfig.TrudgeNaturalSpeed),
                runNaturalSpeed = math.max(0.5f, FeelConfig.RunNaturalSpeed),
            };
            Dependency = localJob.ScheduleParallel(Dependency);

            // --- REMOTE players (position-delta). Single-threaded write to the shared prevPos cache. ---
            // Remote teammates are INTERPOLATED ghosts: their replicated MeleeCombo / SocketCooldown arrive on the
            // interpolation timeline, so their swing windows must be timed against InterpolationTick. Using the
            // predicted ServerTick here desynced a teammate's swing animation from their damage by ~RTT/2 +
            // interp buffer — invisible on loopback (audit finding M1). The LOCAL job above stays on ServerTick:
            // the owning player IS predicted.
            var seen = new NativeParallelHashSet<Entity>(16, Allocator.TempJob);
            var remoteJob = new RemoteDriveJob
            {
                moveX = k_MoveX, moveZ = k_MoveZ, speed = k_Speed, isDead = k_IsDead,
                isAttacking = k_IsAttacking, isFiring = k_IsFiring, isDashing = k_IsDashing,
                comboStep = k_ComboStep, isCone = k_IsCone, abilityDb = abilityBlob,
                serverTick = interpTick, attackTicks = k_AttackAnimTicks,
                dt = dt,
                strideScale = k_StrideScale, trudgeNaturalSpeed = math.max(0.5f, FeelConfig.TrudgeNaturalSpeed),
                runNaturalSpeed = math.max(0.5f, FeelConfig.RunNaturalSpeed),
                inCombat = k_InCombat, combatIdleTicks = combatIdleTicks,
                prevPos = _prevPos,
                seen = seen,
            };
            Dependency = remoteJob.Schedule(Dependency); // .Schedule (not parallel): mutates _prevPos
            // Prune stale entries (despawned remotes) AFTER the job, on the main thread.
            Dependency.Complete();
            PruneCache(seen);
            seen.Dispose();
        }

        void PruneCache(NativeParallelHashSet<Entity> seen)
        {
            using var keys = _prevPos.GetKeyArray(Allocator.Temp);
            for (int i = 0; i < keys.Length; i++)
                if (!seen.Contains(keys[i])) _prevPos.Remove(keys[i]);
        }

        // The swing/fire tick-window predicates (SwingActive/FireActive/SocketFireAndCone) moved to
        // TickWindowMath (Simulation/Combat) 07-15 — shared verbatim with the predicted facing path
        // (PlayerAimSystem); this system passes k_AttackAnimTicks at the call sites.

        // LOCAL: GhostOwnerIsLocal ENABLED -> exactly the owned player. WithPresent<Dead> so alive
        // (Dead-disabled) players are visited. NOTE: GhostOwnerIsLocal as a WithAll filter respects the
        // enable bit; do NOT take it as an `in` parameter (that matches on presence -> drives remotes too).
        [BurstCompile]
        [WithAll(typeof(GhostOwnerIsLocal))]
        [WithPresent(typeof(Dead))]
        partial struct LocalDriveJob : IJobEntity
        {
            public FastAnimatorParameter bank;
            public float bankValue;
            public FastAnimatorParameter inCombat;
            public uint combatIdleTicks;
            public FastAnimatorParameter strideScale;
            public float trudgeNaturalSpeed;
            public float runNaturalSpeed;
            
public FastAnimatorParameter moveX, moveZ, speed, isDead, isAttacking, isFiring, isDashing, comboStep, isCone;
            public BlobAssetReference<AbilityDatabaseBlob> abilityDb;
            public NetworkTick serverTick;
            public uint attackTicks;

            void Execute(
                AnimatorControllerParameterIndexTableComponent indexTable,
                DynamicBuffer<AnimatorControllerParameterComponent> parametersArr,
                in PlayerFacing facing,
                in EffectiveCharacterStats stats,
                in KinematicCharacterBody body,
                in MeleeCombo melee,
                in SocketCooldown socketCd,
                [ReadOnly] DynamicBuffer<AbilitySocket> sockets,
                [ReadOnly] DynamicBuffer<EffectiveSocketStats> effSockets,
                in DashState dashState,
                EnabledRefRO<Dead> dead)
            {
                var a = new AnimatorParametersAspect(parametersArr, indexTable);
                float3 p = AnimParamMath.LocomotionParams(body.RelativeVelocity, facing.Direction, stats.MoveSpeed);
                Write(ref a, p, dead.ValueRO, moveX, moveZ, speed, isDead);
                if (a.HasParameter(isAttacking)) a.SetParameterValue(isAttacking, TickWindowMath.SwingActive(melee, serverTick, attackTicks));
                TickWindowMath.SocketFireAndCone(socketCd, sockets, effSockets, abilityDb, serverTick, attackTicks, out bool firingL, out bool coneL);
                if (a.HasParameter(isFiring)) a.SetParameterValue(isFiring, firingL);
                // Dash lean: the LOCAL player's predicted DashState window [StartTick, IFrameUntilTick+tail).
                bool dashActive = false;
                if (dashState.StartTick != 0u && dashState.IFrameUntilTick != 0u && serverTick.IsValid)
                {
                    var dStart = new NetworkTick(dashState.StartTick);
                    var dEnd = new NetworkTick(TickUtil.NonZero(dashState.IFrameUntilTick + 6u));
                    dashActive = dStart.IsValid && dEnd.IsValid && !dStart.IsNewerThan(serverTick) && dEnd.IsNewerThan(serverTick);
                }
                if (a.HasParameter(isDashing)) a.SetParameterValue(isDashing, dashActive);
                if (a.HasParameter(bank)) a.SetParameterValue(bank, bankValue);
                if (a.HasParameter(strideScale))
                    a.SetParameterValue(strideScale, StrideScaleValue(math.length(body.RelativeVelocity.xz), stats.MoveSpeed, trudgeNaturalSpeed, runNaturalSpeed));

                if (a.HasParameter(comboStep)) a.SetParameterValue(comboStep, (int)melee.Step);
                if (a.HasParameter(isCone)) a.SetParameterValue(isCone, coneL);
                if (a.HasParameter(inCombat)) a.SetParameterValue(inCombat, TickWindowMath.SwingActive(melee, serverTick, combatIdleTicks));
            }
        }

        // REMOTE: GhostOwnerIsLocal DISABLED -> interpolated teammates. Velocity from LocalTransform.Position
        // delta (KinematicCharacterBody.RelativeVelocity is baked-zero on remotes, non-GhostField, owner-only).
        [BurstCompile]
        [WithDisabled(typeof(GhostOwnerIsLocal))]
        [WithPresent(typeof(Dead))]
        partial struct RemoteDriveJob : IJobEntity
        {
            public FastAnimatorParameter moveX, moveZ, speed, isDead, isAttacking, isFiring, isDashing, comboStep, isCone;
            public BlobAssetReference<AbilityDatabaseBlob> abilityDb;
            public NetworkTick serverTick;
            public uint attackTicks;
            public float dt;
            public FastAnimatorParameter strideScale;
            public float trudgeNaturalSpeed;
            public float runNaturalSpeed;
            public NativeParallelHashMap<Entity, float3> prevPos;
            public NativeParallelHashSet<Entity> seen;
            public FastAnimatorParameter inCombat;
            public uint combatIdleTicks;

            void Execute(
                Entity e,
                AnimatorControllerParameterIndexTableComponent indexTable,
                DynamicBuffer<AnimatorControllerParameterComponent> parametersArr,
                in LocalTransform xform,
                in PlayerFacing facing,
                in EffectiveCharacterStats stats,
                in MeleeCombo melee,
                in SocketCooldown socketCd,
                [ReadOnly] DynamicBuffer<AbilitySocket> sockets,
                [ReadOnly] DynamicBuffer<EffectiveSocketStats> effSockets,
                EnabledRefRO<Dead> dead)
            {
                seen.Add(e);
                float3 cur = xform.Position;
                float3 vel = float3.zero;
                if (prevPos.TryGetValue(e, out var prev))
                    vel = (cur - prev) / dt;
                prevPos[e] = cur;

                var a = new AnimatorParametersAspect(parametersArr, indexTable);
                float3 p = AnimParamMath.LocomotionParams(vel, facing.Direction, stats.MoveSpeed);
                Write(ref a, p, dead.ValueRO, moveX, moveZ, speed, isDead);
                if (a.HasParameter(isAttacking)) a.SetParameterValue(isAttacking, TickWindowMath.SwingActive(melee, serverTick, attackTicks));
                TickWindowMath.SocketFireAndCone(socketCd, sockets, effSockets, abilityDb, serverTick, attackTicks, out bool firingR, out bool coneR);
                if (a.HasParameter(isFiring)) a.SetParameterValue(isFiring, firingR);
                if (a.HasParameter(isDashing)) a.SetParameterValue(isDashing, false); // DashState is not replicated to remotes
                if (a.HasParameter(strideScale))
                    a.SetParameterValue(strideScale, StrideScaleValue(math.length(vel.xz), stats.MoveSpeed, trudgeNaturalSpeed, runNaturalSpeed));
                if (a.HasParameter(comboStep)) a.SetParameterValue(comboStep, (int)melee.Step);
                if (a.HasParameter(isCone)) a.SetParameterValue(isCone, coneR);
                if (a.HasParameter(inCombat)) a.SetParameterValue(inCombat, TickWindowMath.SwingActive(melee, serverTick, combatIdleTicks));
            }
        }

        // 07-16e: playback correction against the walk→run BLENDED natural — the two-ring gait tree picks
        // the clip; this keeps residual cadence honest between/beyond the rings. Pure, Burst-safe.
        static float StrideScaleValue(float planarSpeed, float maxSpeed, float walkNatural, float runNatural)
        {
            float maxSp = math.max(0.5f, maxSpeed);
            float walkRing = walkNatural / maxSp;
            float t = math.saturate((planarSpeed / maxSp - walkRing) / math.max(0.05f, 1f - walkRing));
            float natural = math.lerp(walkNatural, runNatural, t);
            return math.clamp(planarSpeed / math.max(0.3f, natural), 0.6f, 2.2f);
        }

        
// ParameterValue has implicit float/bool operators -> SetParameterValue(key, float) / (key, bool) compile.
        static void Write(ref AnimatorParametersAspect a, float3 p, bool isDeadVal,
                          FastAnimatorParameter moveX, FastAnimatorParameter moveZ,
                          FastAnimatorParameter speed, FastAnimatorParameter isDead)
        {
            if (a.HasParameter(moveX))  a.SetParameterValue(moveX, p.x);
            if (a.HasParameter(moveZ))  a.SetParameterValue(moveZ, p.y);
            if (a.HasParameter(speed))  a.SetParameterValue(speed, p.z);
            if (a.HasParameter(isDead)) a.SetParameterValue(isDead, isDeadVal);
        }
    }
}