using UnityEngine;
#if ENABLE_INPUT_SYSTEM
using UnityEngine.InputSystem;
#endif

/// <summary>
/// CharacterController-based player: camera-relative WASD movement, manual gravity and jumping,
/// sliding off too-steep slopes, and a wall/ceiling-climb mode. Wall-climb is entered by pushing
/// the move input into a wall: W/S climb up/down, A/D strafe, the body faces the wall; left-drag
/// leans the visual mesh, right-drag turns the body. Jumping detaches, the top edge mantles over,
/// climbing into an overhang hands off to the ceiling (upright, camera-relative crawl).
/// Named PlayerCharacterController to avoid a clash with Unity.VisualScripting's "PlayerController".
/// </summary>
[RequireComponent(typeof(CharacterController))]
[DisallowMultipleComponent]
public class PlayerCharacterController : MonoBehaviour
{
    [Header("Movement")]
    [Tooltip("Horizontal movement speed (units/second).")]
    public float moveSpeed = 2f;

    [Tooltip("Speed multiplier applied to ground movement and wall/ceiling climbing while the sprint key (Left Shift) is held.")]
    public float sprintSpeedMultiplier = 3.2f;

    [Tooltip("How quickly ground movement ramps up to the target speed (units/second²). Lower = more gradual start.")]
    public float acceleration = 30f;

    [Tooltip("How quickly ground movement slows to a stop when input eases off (units/second²). Lower = more glide.")]
    public float deceleration = 45f;

    [Tooltip("Interpret WASD relative to the camera (off = world X/Z axes).")]
    public bool cameraRelative = true;

    [Tooltip("Camera used for camera-relative movement. Empty = Camera.main.")]
    public Transform cameraTransform;

    [Header("Rotation")]
    [Tooltip("Smoothly turn the character to face its movement direction.")]
    public bool rotateTowardMovement = true;

    [Tooltip("Turn speed in degrees per second.")]
    public float rotationSpeed = 540f;

    [Header("Jump & Gravity")]
    [Tooltip("Peak jump height in units.")]
    public float jumpHeight = 1.2f;

    [Tooltip("Gravity in units per second squared (negative = downward).")]
    public float gravity = -14.715f;

    [Tooltip("Small downward velocity kept while grounded for reliable ground contact.")]
    public float groundedStickVelocity = -2f;

    [Tooltip("Downward speed (units/second) past which the player counts as falling, for the fall " +
             "animation. Only while airborne (not grounded, not wall-climbing). Scales with player size.")]
    public float fallAnimationSpeed = 4f;

    [Header("Rescue")]
    [Tooltip("Kill-plane fail-safe: if the player falls below this world Y (e.g. off the map into the void), " +
             "they are teleported back to where this avatar spawned (spawn center + per-client ring offset) " +
             "with all momentum cleared. Owner-only; the authoritative NetworkTransform replicates the reset.")]
    public float rescueMinY = -100f;

    [Header("Slope Sliding")]
    [Tooltip("Slide down surfaces steeper than the CharacterController's Slope Limit instead of balancing on them.")]
    public bool slideDownSteepSlopes = true;

    [Tooltip("How quickly the slide accelerates (units/second squared).")]
    public float slideAcceleration = 20f;

    [Tooltip("Maximum downhill slide speed (units/second).")]
    public float maxSlideSpeed = 8f;

    [Tooltip("Steering control kept while sliding (0 = none, 1 = full).")]
    [Range(0f, 1f)]
    public float slideControl = 0.3f;

    [Header("Wall Climb")]
    [Tooltip("Enter wall-climb mode by pushing into a wall: stick to the surface, move at reduced speed, ignore gravity and jumping.")]
    public bool enableWallClimb = true;

    [Tooltip("Minimum surface angle from 'up' (degrees) that counts as a climbable wall/ceiling rather than a slope.")]
    [Range(50f, 180f)]
    public float wallMinAngle = 60f;

    [Tooltip("How directly the move input must point into a wall to grab it (0 = any inward nudge, 1 = head-on only). Stops mere contact (e.g. standing at a wall's base) from grabbing.")]
    [Range(0f, 1f)]
    public float wallGrabMinPush = 0.3f;

    [Tooltip("Speed multiplier for climbing up and strafing while wall-climbing (0.5 = half speed).")]
    [Range(0f, 1f)]
    public float wallClimbSpeedMultiplier = 0.5f;

    [Tooltip("How quickly wall/ceiling climb movement ramps up to speed (units/second²). Kept low so brief " +
             "taps nudge only a little for precise placement; scaled up while sprinting so sprint stays snappy.")]
    [Min(0.01f)]
    public float wallClimbAcceleration = 5f;

    [Tooltip("Speed multiplier for the mantle (pulling up over the top edge), independent of the climb speed. Multiplies moveSpeed; 1 = full walk speed, >1 = snappier pull-up.")]
    [Min(0f)]
    public float wallMantleSpeedMultiplier = 1.5f;

    [Tooltip("Farthest the mesh can lean out from the wall via the mouse-drag offset (units).")]
    public float wallMaxOffset = 0.1f;

    [Tooltip("Farthest the mesh can sink INTO the wall via the mouse-drag offset (units). Only the visual model + its paint collider move; the CharacterController capsule stays put, so this isn't blocked by the wall collider.")]
    public float wallMaxInset = 0.2f;

    [Tooltip("Units the lean-out offset changes per pixel of vertical mouse drag (left button held).")]
    public float wallOffsetSensitivity = 0.001f;

    [Tooltip("Degrees the body turns per pixel of horizontal mouse drag (left button held) while climbing.")]
    public float wallRotateSensitivity = 0.2f;

    [Tooltip("How fast the lean-out offset eases back to the wall while moving (units/second).")]
    public float wallOffsetReturnSpeed = 2f;

    [Tooltip("How snappily the body follows the lean-out offset (1/second). Higher = tighter, lower = smoother.")]
    public float wallOffsetFollow = 12f;

    [Tooltip("Grace period (seconds) of lost contact tolerated before leaving wall-climb mode.")]
    public float wallExitGrace = 0.15f;

    [Tooltip("How long (seconds) the top-edge signature (probe clear, wall still at the feet, clear headroom above) must persist before committing to a top-out mantle. Filters transient probe misses so they never trigger a mantle mid-face. Keep small; a couple of frames is enough.")]
    public float wallTopOutConfirm = 0.06f;

    [Tooltip("Head-to-ceiling distance (units) at which climbing a wall up into an overhang hands off to the ceiling.")]
    public float ceilingGrabDistance = 0.02f;

    [Tooltip("Upward hop when topping out over a wall/slope edge, so holding W carries you onto the ledge instead of dropping back onto the face and re-grabbing. In meters of jump height; 0 = no hop.")]
    public float wallTopOutBoost = 0.3f;

    [Tooltip("Colliders with this tag are invisible to wall-climb and ceiling-grab: they still block the capsule physically, but can never be grabbed, re-probed onto, or used as a ceiling. Leave empty to disable.")]
    public string noClimbTag = "NoClimb";

    [Tooltip("Camera orbit input; paused while dragging the wall-climb offset. Auto-found if empty.")]
    [SerializeField] private ThirdPersonOrbitInput cameraOrbit;

    [Tooltip("Visual model root moved by the wall-climb lean offset (into/out of the wall) while the capsule stays put. Must parent both the skinned mesh and its bones. Auto-resolved from the SkinnedMeshRenderer if empty.")]
    [SerializeField] private Transform meshOffsetTarget;

    [Tooltip("Camera follow/look target (what the ThirdPersonCamera tracks). Moved vertically by the active pose's camera y-offset plus the ceiling offset, without moving the body. Auto-resolved from a child named \"CameraTarget\" if empty.")]
    [SerializeField] private Transform cameraTarget;

    /// <summary>When false, movement/jump input is ignored but gravity and ground contact keep
    /// running. Toggled by the GameModeManager.</summary>
    public bool ControlEnabled { get; set; } = true;

    /// <summary>When false, gravity, ground-stick and slope-sliding are suspended so the avatar
    /// hovers at its spawn position. Set by the GameModeManager during the pre-Hide loading barrier.</summary>
    public bool GravityEnabled { get; set; } = true;

    /// <summary>When set, the body faces this world-space yaw (degrees) every frame instead of turning
    /// toward its movement direction (first-person). Only affects ground/air locomotion — wall-climb
    /// owns its own facing.</summary>
    public float? FaceYaw { get; set; }

    /// <summary>True while in wall-climb mode.</summary>
    public bool IsWallClimbing => _isWallClimbing;

    /// <summary>True while the player is idle (under control and essentially still). Snapshotted at
    /// the end of Update so a sibling reads a stable, order-independent value.</summary>
    public bool IsIdle => _isIdle;

    /// <summary>True while the sprint key is held, in any state.</summary>
    public bool IsSprinting => _sprinting;

    /// <summary>True while stuck to a ceiling (wall-climb mode with a downward-facing surface normal).</summary>
    public bool IsOnCeiling => _isWallClimbing && _onCeiling;

    /// <summary>True while grounded and moving above the run threshold; airborne / wall / standing
    /// all read false. The pose system picks its walk/run clips off this.</summary>
    public bool IsMovingOnGround => _movingOnGround;

    /// <summary>True while airborne (not wall-climbing) and descending faster than
    /// <see cref="fallAnimationSpeed"/> (scaled by player size).</summary>
    public bool IsFalling => _isFalling;

    /// <summary>
    /// Set by <see cref="PlayerPoseController"/> while a pose Playable graph owns the Animator output.
    /// While set, the run-bool is not poked: the graph overrides it and Unity would log
    /// "Animator is not playing an AnimatorController" every frame.
    /// </summary>
    public bool AnimatorOverridden { get; set; }

    /// <summary>
    /// The visual-model transform moved by the wall-lean / ceiling offset; its localPosition is owned
    /// solely by <see cref="SetMeshLean"/>. Exposed so <see cref="PlayerPoseController"/> can exclude
    /// it from its per-frame rest reset (the Animator sits on this same node and would otherwise wipe
    /// the offset every frame).
    /// </summary>
    public Transform MeshOffsetTarget => meshOffsetTarget;

    /// <summary>Authored CharacterController capsule center Y, captured in Awake. The per-pose capsule
    /// (driven by <see cref="PlayerPoseController"/>) eases back to this when no pose overrides it.</summary>
    public float BaseCapsuleCenterY { get; private set; }

    /// <summary>Authored CharacterController capsule radius, captured in Awake.</summary>
    public float BaseCapsuleRadius { get; private set; }

    /// <summary>Authored CharacterController capsule height, captured in Awake.</summary>
    public float BaseCapsuleHeight { get; private set; }

    // Below this horizontal speed (m/s, squared) the character counts as idle for the run animation.
    private const float RunningSpeedThresholdSqr = 0.04f; // (0.2 m/s)^2

    private CharacterController _controller;
    private NetworkPlayerSetup _setup;    // sibling role source; null on non-networked test instances
    private float _verticalVelocity;
    private Vector3 _horizontalVelocity;  // smoothed horizontal move velocity
    private Vector3 _climbVelocity;       // smoothed along-surface climb velocity
    private bool _sprinting;
    private bool _isIdle;
    private bool _movingOnGround;
    private bool _isFalling;
    private float _groundOffset;          // signed vertical mesh raise from the ground mouse pose-adjust
    private Vector3 _spawnPosition;       // rescue (kill-plane) teleport target
    private bool _spawnCaptured;          // false until the first Update (after OnNetworkSpawn's ring offset has landed)

    private Vector3 _groundNormal = Vector3.up;
    private bool _groundNormalUpdated;
    private float _slideSpeed;

    // A climb surface counts as a ceiling once its normal points down past this threshold; the
    // enter/exit band is hysteretic because in an inner wall/ceiling corner the per-frame contact
    // normal crosses a single threshold back and forth, flipping the climb mode and body yaw.
    private const float CeilingNormalThreshold = -0.5f;
    private const float CeilingEnterThreshold = -0.6f; // wall -> ceiling only when clearly down-facing
    private const float CeilingExitThreshold = -0.4f;  // ceiling -> wall only when clearly not down-facing
    private bool _onCeiling;              // latched climb-surface class (hysteretic)
    private bool _isWallClimbing;
    private Vector3 _wallNormal;
    private Vector3 _wallNormalAccum;     // summed wall normals during the latest Move
    private bool _wallContactThisFrame;
    private float _lostContactTimer;
    private float _wallOffset;            // signed mesh lean (mouse drag); moves only the model, not the capsule
    private float _wallYaw;               // body yaw offset from facing the wall (mouse drag)
    private int _wallStrafeSign;          // latched strafe direction; 0 = unlatched
    private int _wallClimbSign;           // latched up/down direction; 0 = unlatched
    private bool _offsetDragging;         // true while the offset/rotation is being set (pauses camera orbit)
    private bool _climbLeftGround;        // true once the capsule has left the ground while climbing
    private Vector3 _meshBaseLocalPos;
    private Vector3 _cameraTargetBaseLocalPos;
    private float _cameraYOffset;         // cached so an unchanged value skips the transform write
    private float _meshOffsetResidual;    // leftover mesh lean still easing back to 0 after leaving the wall
    private Vector3 _meshOffsetExitNormal; // wall normal latched at exit (the live one may shift after detaching)
    private readonly RaycastHit[] _wallProbe = new RaycastHit[16];
    private bool _wallProbeSaturated;     // log-once: a full buffer can hide the nearest valid hit

    // Mantle (top-out) state.
    private const float TopOutRegrabCooldown = 0.3f; // blocks re-grab right after a top-out (no detach/re-grab buzzing)
    private bool _mantling;
    private bool _mantleClearedFeet;      // phase 1 done: capsule fully above the edge
    private float _mantleOverDist;        // phase 2 forward distance over the top
    private float _mantleTimer;           // safety cap
    private float _reentryCooldown;

    void Awake()
    {
        _controller = GetComponent<CharacterController>();
        _setup = GetComponent<NetworkPlayerSetup>();
        BaseCapsuleCenterY = _controller.center.y;
        BaseCapsuleRadius = _controller.radius;
        BaseCapsuleHeight = _controller.height;
        if (!cameraTransform && Camera.main)
            cameraTransform = Camera.main.transform;
        if (!cameraOrbit)
            cameraOrbit = FindFirstObjectByType<ThirdPersonOrbitInput>();

        // Walk up from the skinned mesh to the topmost node under this transform so the offset root
        // parents BOTH the renderer and its bones (offsetting only the renderer would move just the
        // baked paint collider, not the bone-driven visible mesh).
        if (!meshOffsetTarget)
        {
            var smr = GetComponentInChildren<SkinnedMeshRenderer>();
            if (smr)
            {
                Transform t = smr.transform;
                while (t.parent && t.parent != transform) t = t.parent;
                meshOffsetTarget = t;
            }
        }
        if (meshOffsetTarget) _meshBaseLocalPos = meshOffsetTarget.localPosition;

        if (!cameraTarget)
        {
            Transform t = transform.Find("CameraTarget");
            if (t) cameraTarget = t;
        }
        if (cameraTarget) _cameraTargetBaseLocalPos = cameraTarget.localPosition;
    }

    void Update()
    {
        // Kill-plane fail-safe; runs ahead of the control gate so it rescues in any mode.
        if (!_spawnCaptured)
        {
            _spawnPosition = transform.position;
            _spawnCaptured = true;
        }
        else if (transform.position.y < rescueMinY)
        {
            RescueToSpawn();
            return;
        }

        float h = 0f, v = 0f;
        bool jumpPressed = false;
        bool sprinting = false;

        // Skip input when control is disabled (e.g. paint mode); gravity and grounding still run.
        if (ControlEnabled)
        {
#if ENABLE_INPUT_SYSTEM
            var keyboard = Keyboard.current;
            if (keyboard != null)
            {
                if (keyboard.aKey.isPressed) h -= 1f;
                if (keyboard.dKey.isPressed) h += 1f;
                if (keyboard.sKey.isPressed) v -= 1f;
                if (keyboard.wKey.isPressed) v += 1f;
                jumpPressed = keyboard.spaceKey.wasPressedThisFrame;
                sprinting = keyboard.leftShiftKey.isPressed;
            }
#else
            h = Input.GetAxisRaw("Horizontal");
            v = Input.GetAxisRaw("Vertical");
            jumpPressed = Input.GetButtonDown("Jump");
            sprinting = Input.GetKey(KeyCode.LeftShift);
#endif
        }

        _sprinting = sprinting;

        Vector3 inputDir = new Vector3(h, 0f, v);
        if (inputDir.sqrMagnitude > 1f)
            inputDir.Normalize();

        Vector3 moveDir;
        if (cameraRelative && cameraTransform)
        {
            Vector3 forward = cameraTransform.forward;
            forward.y = 0f;
            forward.Normalize();
            Vector3 right = cameraTransform.right;
            right.y = 0f;
            right.Normalize();
            moveDir = forward * inputDir.z + right * inputDir.x;
        }
        else
        {
            moveDir = inputDir;
        }

        UpdateWallClimbState(moveDir);

        // Latch the wall normal from contacts ONLY while not yet climbing (the grab needs it).
        // During a climb the probes own _wallNormal: contact normals mix wall and ceiling in inner
        // corners and would flip the classification frame to frame.
        if (!_isWallClimbing && _wallContactThisFrame && _wallNormalAccum.sqrMagnitude > 1e-6f)
            _wallNormal = _wallNormalAccum.normalized;
        _wallContactThisFrame = false;
        _wallNormalAccum = Vector3.zero;

        if (_isWallClimbing)
        {
            // Frozen on the wall while control is off: keep the grip so switching modes never drops us.
            if (ControlEnabled)
                ApplyWallClimbMovement(h, v, moveDir, jumpPressed, sprinting, Time.deltaTime);
            else
                _offsetDragging = false;
            if (cameraOrbit)
                cameraOrbit.LookSuppressed = _offsetDragging;
            _horizontalVelocity = Vector3.zero;
            _isIdle = ControlEnabled && (h * h + v * v) <= 1e-4f;
            _movingOnGround = false;
            _isFalling = false;
            return;
        }

        // Ground pose-adjust (the wall mouse scheme mirrored to the ground). Gated to player control
        // so it never fights painting (paint mode owns the left button).
        bool groundYawDrag = false;
        if (ControlEnabled)
            groundYawDrag = HandleGroundPoseAdjust(h, v, Time.deltaTime);
        else
            _offsetDragging = false;
        if (cameraOrbit)
            cameraOrbit.LookSuppressed = _offsetDragging;

        EaseMeshOffsetToRest(Time.deltaTime);

        // A ground normal steeper than the slope limit is too steep to stand on
        // (also covers balancing on a sharp box edge).
        float slopeAngle = Vector3.Angle(_groundNormal, Vector3.up);
        bool onSteepSlope = slideDownSteepSlopes
            && GravityEnabled
            && _controller.isGrounded
            && slopeAngle > _controller.slopeLimit + 0.01f;

        if (!GravityEnabled)
        {
            _verticalVelocity = 0f;
        }
        else
        {
            if (_controller.isGrounded)
            {
                if (_verticalVelocity < 0f)
                    _verticalVelocity = groundedStickVelocity;

                if (jumpPressed && !onSteepSlope)
                    _verticalVelocity = Mathf.Sqrt(jumpHeight * -2f * gravity);
            }

            _verticalVelocity += gravity * Time.deltaTime;
        }

        Vector3 slideVelocity = Vector3.zero;
        if (onSteepSlope)
        {
            Vector3 slideDir = Vector3.ProjectOnPlane(Vector3.down, _groundNormal).normalized;
            _slideSpeed = Mathf.Min(_slideSpeed + slideAcceleration * Time.deltaTime, maxSlideSpeed);
            slideVelocity = slideDir * _slideSpeed;
            moveDir *= slideControl;
        }
        else
        {
            _slideSpeed = 0f;
        }

        float currentSpeed = sprinting ? moveSpeed * sprintSpeedMultiplier : moveSpeed;
        Vector3 targetHorizontal = moveDir * currentSpeed;
        float accelRate = moveDir.sqrMagnitude > 0.0001f ? acceleration : deceleration;
        _horizontalVelocity = Vector3.MoveTowards(_horizontalVelocity, targetHorizontal, accelRate * Time.deltaTime);
        Vector3 velocity = _horizontalVelocity + slideVelocity + Vector3.up * _verticalVelocity;

        // Move fires OnControllerColliderHit, which refills the ground normal.
        _groundNormalUpdated = false;
        _controller.Move(velocity * Time.deltaTime);
        if (!_groundNormalUpdated)
            _groundNormal = Vector3.up;

        if (FaceYaw.HasValue)
        {
            transform.rotation = Quaternion.Euler(0f, FaceYaw.Value, 0f);
        }
        else if (rotateTowardMovement && !groundYawDrag && moveDir.sqrMagnitude > 0.0001f)
        {
            Quaternion target = Quaternion.LookRotation(moveDir, Vector3.up);
            transform.rotation = Quaternion.RotateTowards(
                transform.rotation, target, rotationSpeed * Time.deltaTime);
        }

        // Real horizontal speed, so pushing into a wall (blocked) reads as idle, not foot-sliding.
        Vector3 horizontalVel = _controller.velocity;
        horizontalVel.y = 0f;
        bool movingOnGround = _controller.isGrounded && horizontalVel.sqrMagnitude > RunningSpeedThresholdSqr;
        _movingOnGround = movingOnGround;
        _isIdle = ControlEnabled && _controller.isGrounded && !movingOnGround;
        _isFalling = !_controller.isGrounded && _verticalVelocity < -fallAnimationSpeed * CapsuleScale;
    }

    /// <summary>Kill-plane rescue: snap back to the captured spawn point and clear all momentum.</summary>
    private void RescueToSpawn()
    {
        CharacterTeleport.Move(_controller, transform, _spawnPosition);

        _verticalVelocity = 0f;
        _horizontalVelocity = Vector3.zero;
        _climbVelocity = Vector3.zero;
        _slideSpeed = 0f;
    }

    // Hunters may not grab a wall during the hide phase; every other role/phase climbs normally.
    private bool WallClimbBlockedNow()
    {
        var match = MatchManager.Instance;
        return match && match.LocalSubPhase == MatchManager.MatchSubPhase.Hide
               && _setup && _setup.Role == PlayerRole.Hunter;
    }

    /// <summary>
    /// Enters wall-climb mode only when the move input actively pushes into a wall (not on mere
    /// contact). Leaving while climbing is handled in <see cref="ApplyWallClimbMovement"/>.
    /// </summary>
    private void UpdateWallClimbState(Vector3 moveDir)
    {
        if (_reentryCooldown > 0f)
            _reentryCooldown -= Time.deltaTime;

        if (!enableWallClimb || WallClimbBlockedNow())
        {
            if (_isWallClimbing)
                ExitWallClimb();
            return;
        }

        // A wall is grabbed by pushing horizontally into it while not rising; a ceiling can't be
        // pushed into horizontally, so it is grabbed by rising up into it.
        bool pushingIn = false;
        if (_wallContactThisFrame && _wallNormalAccum.sqrMagnitude > 1e-6f)
        {
            Vector3 surfaceNormal = _wallNormalAccum.normalized;
            if (surfaceNormal.y < CeilingNormalThreshold)
                pushingIn = _verticalVelocity > 0f;
            else
                pushingIn = moveDir.sqrMagnitude > 1e-4f
                    && Vector3.Dot(moveDir.normalized, surfaceNormal) <= -wallGrabMinPush
                    && _verticalVelocity <= 0f;
        }

        // Grab only under player control; once climbing we stay attached across control toggles.
        // The cooldown prevents instantly re-grabbing the edge we just mantled over.
        if (!_isWallClimbing && ControlEnabled && pushingIn && _reentryCooldown <= 0f)
        {
            _isWallClimbing = true;
            _wallNormal = _wallNormalAccum.normalized;
            _onCeiling = _wallNormal.y < CeilingNormalThreshold;
            _lostContactTimer = 0f;
            _verticalVelocity = 0f;
            _slideSpeed = 0f;
            _wallOffset = 0f;
            _groundOffset = 0f;
            _meshOffsetResidual = 0f;
            _wallYaw = 0f;
            _wallStrafeSign = 0;
            _wallClimbSign = 0;
            _climbLeftGround = false;
            _climbVelocity = Vector3.zero;
        }
    }

    /// <summary>
    /// Movement while climbing, walls and ceilings (distinguished by the surface normal). WALL: W/S
    /// climb straight up/down, A/D strafe camera-relative, the body faces the wall. CEILING: upright,
    /// WASD camera-relative in the horizontal plane. The surface is re-probed each frame; a wall's
    /// top edge mantles, climbing into an overhang hands off to the ceiling.
    /// </summary>
    private void ApplyWallClimbMovement(float h, float v, Vector3 moveDir, bool jumpPressed, bool sprinting, float dt)
    {
        _offsetDragging = false;

        if (_mantling)
        {
            MantleOverEdge(dt);
            return;
        }

        UpdateCeilingClass();
        bool onCeiling = _onCeiling;

        // Map W/S to UP/DOWN by which key pushes INTO the wall (facing the wall that's W; with the
        // camera on the wall's side it's S). Latched once per press; without the remap the grab
        // (camera-relative) and the base-release (raw S) disagree and the climb flickers.
        bool climbing = Mathf.Abs(v) > 1e-4f;
        if (!climbing)
            _wallClimbSign = 0;
        else if (_wallClimbSign == 0 && !onCeiling)
        {
            Vector3 camFwd = cameraTransform ? cameraTransform.forward : Vector3.zero;
            camFwd.y = 0f;
            _wallClimbSign = (cameraTransform && Vector3.Dot(camFwd, _wallNormal) > 0f) ? -1 : 1;
        }
        float vEff = _wallClimbSign != 0 ? v * _wallClimbSign : v;

        // Jump detaches: off a wall it pushes straight up, off a ceiling it just lets go.
        if (jumpPressed)
        {
            ExitWallClimb();
            _verticalVelocity = onCeiling ? 0f : Mathf.Sqrt(jumpHeight * -2f * gravity);
            return;
        }

        // Wall->ceiling hand-off: while climbing up into an overhang, switch to the ceiling right
        // above the head instead of trying to mantle over a (non-existent) top.
        if (!onCeiling && vEff > 0f
            && ProbeCeiling(out Vector3 ceilNormal, out float ceilHeadGap)
            && ceilHeadGap <= ceilingGrabDistance)
        {
            _wallNormal = ceilNormal;
            _onCeiling = true;
            onCeiling = true;
            _wallOffset = 0f;
        }

        // Re-measure the surface each frame, probing the kind we're committed to. On a ceiling probe
        // straight UP, not along -_wallNormal: in an inner corner that ray would clip the wall and
        // demote us to "wall", flipping the body's facing every frame.
        bool found;
        float gap;
        if (onCeiling)
        {
            found = ProbeCeiling(out Vector3 ceilNormal2, out float ceilGap);
            if (found)
            {
                _wallNormal = ceilNormal2;
                gap = ceilGap;
                _lostContactTimer = 0f;
            }
            else
            {
                found = ProbeWall(out Vector3 wallNormal, out gap);
                if (found)
                {
                    _wallNormal = wallNormal;
                    _lostContactTimer = 0f;
                }
                UpdateCeilingClass();
                onCeiling = _onCeiling;
            }
        }
        else
        {
            found = ProbeWall(out Vector3 probedNormal, out gap);
            if (found)
            {
                _wallNormal = probedNormal;
                _lostContactTimer = 0f;
                UpdateCeilingClass();
                onCeiling = _onCeiling;
            }
        }

        // Topped out onto a slope: the climbed face has flattened into something walkable. Hand back
        // to grounded movement; hop only when actually moving up onto it (a real top-out).
        if (found && !onCeiling && _climbLeftGround
            && Vector3.Angle(_wallNormal, Vector3.up) < wallMinAngle)
        {
            if (vEff > 0f) TopOutDetach();
            else ExitWallClimb();
            return;
        }

        Vector3 alongSurface;
        if (onCeiling)
        {
            alongSurface = Vector3.ProjectOnPlane(moveDir, _wallNormal);
        }
        else
        {
            // W/S climb straight up/down; strafe along the wall's own horizontal tangent, not live
            // camera-right (that coupled movement to the orbit camera's per-frame re-aim).
            Vector3 wallUp = Vector3.ProjectOnPlane(Vector3.up, _wallNormal);
            if (wallUp.sqrMagnitude > 1e-6f) wallUp.Normalize();
            Vector3 wallRight = Vector3.Cross(_wallNormal, wallUp);
            if (wallRight.sqrMagnitude > 1e-6f) wallRight.Normalize();

            // Pick the strafe sign ONCE from the camera when a strafe begins, then hold it:
            // re-deciding per frame inverts the input while rounding a curved wall.
            bool strafing = Mathf.Abs(h) > 1e-4f;
            if (!strafing)
                _wallStrafeSign = 0;
            else if (_wallStrafeSign == 0)
                _wallStrafeSign = (cameraTransform && Vector3.Dot(cameraTransform.right, wallRight) < 0f) ? -1 : 1;
            if (_wallStrafeSign < 0)
                wallRight = -wallRight;

            alongSurface = wallUp * vEff + wallRight * h;
        }
        if (alongSurface.sqrMagnitude > 1f) alongSurface.Normalize();
        bool hasMoveInput = (h * h + v * v) > 1e-4f;

        if (!found)
        {
            _lostContactTimer += dt;

            // Wall top-out: probe lost the wall while climbing up, wall still at the feet, clear
            // headroom above the center. Confirmed briefly before committing so a transient miss
            // (which re-acquires within a frame or two) never mantles mid-face.
            if (!onCeiling && alongSurface.y > 0f && AtWallTopEdge())
            {
                if (_lostContactTimer >= wallTopOutConfirm)
                {
                    _mantling = true;
                    _mantleClearedFeet = false;
                    _mantleOverDist = 0f;
                    _mantleTimer = 0f;
                    MantleOverEdge(dt);
                    return;
                }
            }
            // Surface genuinely gone (incl. crawling off a ceiling edge): leave after grace.
            else if (_lostContactTimer >= wallExitGrace)
            {
                ExitWallClimb();
                return;
            }
        }

        // Left drag = signed lean (moves only the visual mesh); right drag = body turn.
        // The lean eases home while moving; either drag pauses the camera orbit.
        bool offsetDrag = found && InputUtil.LeftMouseHeld();
        bool yawDrag = found && InputUtil.RightMouseHeld();
        if (offsetDrag || yawDrag)
        {
            _offsetDragging = true;
            Vector2 drag = InputUtil.ReadMouseDelta();
            if (offsetDrag)
                _wallOffset = Mathf.Clamp(_wallOffset - drag.y * wallOffsetSensitivity, -wallMaxInset, wallMaxOffset);
            if (yawDrag)
            {
                if (onCeiling)
                    transform.Rotate(0f, drag.x * wallRotateSensitivity, 0f, Space.World);
                else
                    _wallYaw += drag.x * wallRotateSensitivity;
            }
        }
        if (!offsetDrag && hasMoveInput)
        {
            _wallOffset = Mathf.MoveTowards(_wallOffset, 0f, wallOffsetReturnSpeed * dt);
        }
        SetMeshLean(_wallNormal, _wallOffset);

        float climbSpeed = moveSpeed * wallClimbSpeedMultiplier;
        if (sprinting) climbSpeed *= sprintSpeedMultiplier;
        // Ramp the along-surface velocity instead of snapping: a brief tap moves only a little.
        // Sprint scales the accel too; releasing decelerates at the ground rate.
        Vector3 targetAlong = alongSurface.sqrMagnitude > 1e-6f
            ? alongSurface.normalized * climbSpeed
            : Vector3.zero;
        float climbAccel = targetAlong.sqrMagnitude > 1e-6f
            ? wallClimbAcceleration * (sprinting ? sprintSpeedMultiplier : 1f)
            : deceleration;
        _climbVelocity = Vector3.MoveTowards(_climbVelocity, targetAlong, climbAccel * dt);
        Vector3 velocity = _climbVelocity;
        if (found)
        {
            // Servo the capsule to one skin-width off the surface. Exponential follow keeps it
            // framerate-stable; the clamp guards spikes.
            float maxPerpSpeed = 8f * CapsuleScale;
            float gapError = _controller.skinWidth * CapsuleScale - gap;
            float follow = 1f - Mathf.Exp(-wallOffsetFollow * dt);
            velocity += _wallNormal * Mathf.Clamp(gapError * follow / dt, -maxPerpSpeed, maxPerpSpeed);
        }

        _controller.Move(velocity * dt);

        // Reaching walkable ground detaches. Probed under the feet rather than trusting isGrounded
        // (the standoff servo can hold the capsule just off the surface). The vEff < 0 release is
        // the only detach that doesn't require having left the ground first, so a wall grabbed at
        // its base can be released by pressing away.
        bool onWalkableGround = _controller.isGrounded || WalkableGroundBelow();
        if (!onWalkableGround)
        {
            _climbLeftGround = true;
        }
        else if (_climbLeftGround && vEff > 0f)
        {
            TopOutDetach();
            return;
        }
        else if (_climbLeftGround || vEff < 0f)
        {
            ExitWallClimb();
            return;
        }

        if (rotateTowardMovement)
        {
            if (onCeiling)
            {
                // Stay upright and face the horizontal move direction, unless the right-button
                // turn is actively steering the body.
                if (!yawDrag)
                {
                    Vector3 dir = alongSurface;
                    dir.y = 0f;
                    if (dir.sqrMagnitude > 1e-4f)
                    {
                        Quaternion target = Quaternion.LookRotation(dir.normalized, Vector3.up);
                        transform.rotation = Quaternion.RotateTowards(
                            transform.rotation, target, rotationSpeed * dt);
                    }
                }
            }
            else
            {
                // Face the wall (forward = into the wall), turned by the held mouse-drag yaw.
                Vector3 faceWall = -_wallNormal;
                faceWall.y = 0f;
                if (faceWall.sqrMagnitude > 0.0001f)
                {
                    Vector3 dir = Quaternion.AngleAxis(_wallYaw, Vector3.up) * faceWall.normalized;
                    transform.rotation = Quaternion.LookRotation(dir, Vector3.up);
                }
            }
        }
    }

    /// <summary>Updates the latched wall/ceiling classification (hysteretic; see the thresholds).</summary>
    private void UpdateCeilingClass()
    {
        if (_onCeiling)
        {
            if (_wallNormal.y > CeilingExitThreshold) _onCeiling = false;
        }
        else if (_wallNormal.y < CeilingEnterThreshold)
        {
            _onCeiling = true;
        }
    }

    /// <summary>
    /// Places the visual model at the given signed lean along <paramref name="dir"/> (world space),
    /// relative to its authored local pose; the capsule is untouched, so the lean can sink into the
    /// wall where the capsule would be blocked.
    /// </summary>
    private void SetMeshLean(Vector3 dir, float offset)
    {
        if (!meshOffsetTarget) return;
        Vector3 worldOffset = dir * offset;
        meshOffsetTarget.localPosition = _meshBaseLocalPos
            + transform.InverseTransformVector(worldOffset)
            + Vector3.up * _groundOffset;
    }

    /// <summary>
    /// Re-applies the resting mesh offset every non-climbing frame in a single write: eases the
    /// leftover wall lean home (along the latched exit normal) while composing in the ground raise.
    /// Writing unconditionally keeps this the sole owner of the offset transform.
    /// </summary>
    private void EaseMeshOffsetToRest(float dt)
    {
        if (_meshOffsetResidual != 0f)
            _meshOffsetResidual = Mathf.MoveTowards(_meshOffsetResidual, 0f, wallOffsetReturnSpeed * dt);
        SetMeshLean(_meshOffsetExitNormal, _meshOffsetResidual);
    }

    /// <summary>
    /// Ground pose-adjust, mirroring the wall-climb mouse scheme: LEFT drag raises/lowers the visual
    /// mesh (capsule untouched), RIGHT drag turns the body. Returns true while a right-button turn
    /// is active so the caller skips rotate-toward-movement that frame.
    /// </summary>
    private bool HandleGroundPoseAdjust(float h, float v, float dt)
    {
        _offsetDragging = false;

        bool offsetDrag = InputUtil.LeftMouseHeld();
        bool yawDrag = InputUtil.RightMouseHeld();
        bool hasMoveInput = (h * h + v * v) > 1e-4f;

        if (offsetDrag || yawDrag)
        {
            _offsetDragging = true;
            Vector2 drag = InputUtil.ReadMouseDelta();
            if (offsetDrag)
                _groundOffset = Mathf.Clamp(
                    _groundOffset + drag.y * wallOffsetSensitivity, -wallMaxInset, wallMaxOffset);
            if (yawDrag)
                transform.Rotate(0f, drag.x * wallRotateSensitivity, 0f, Space.World);
        }

        // The raise eases home only while actually moving; standing still holds it for posing.
        if (!offsetDrag && hasMoveInput)
            _groundOffset = Mathf.MoveTowards(_groundOffset, 0f, wallOffsetReturnSpeed * dt);

        return yawDrag;
    }

    /// <summary>
    /// Resizes the CharacterController capsule to the active pose's dimensions, driven by
    /// <see cref="PlayerPoseController"/>. Only the collision capsule changes. Cached so an
    /// unchanged value skips the write (a resize re-bakes the capsule internally).
    /// </summary>
    public void SetCapsule(float centerY, float radius, float height)
    {
        Vector3 c = _controller.center;
        if (c.y == centerY && _controller.radius == radius && _controller.height == height) return;
        c.y = centerY;
        _controller.center = c;
        _controller.radius = radius;
        _controller.height = height;
    }

    /// <summary>
    /// Places the camera target at the given local-up offset relative to its authored local position,
    /// without moving the body. Driven by <see cref="PlayerPoseController"/>; 0 restores the authored
    /// height. Cached so an unchanged value skips the write.
    /// </summary>
    public void SetCameraTargetLocalYOffset(float y)
    {
        if (!cameraTarget || _cameraYOffset == y) return;
        _cameraYOffset = y;
        cameraTarget.localPosition = _cameraTargetBaseLocalPos + Vector3.up * y;
    }

    // The serialized capsule center/radius/height are authored at scale-1; transform.localScale
    // resizes the actual collision capsule but not those numbers. Every climb probe casts in WORLD
    // space, so it must use the scaled dimensions and scale its distance paddings too. Uniform
    // player scale is enforced by PlayerScaler, so a single lossyScale component suffices.
    private float CapsuleScale => transform.lossyScale.y;
    private Vector3 WorldCapsuleCenter => transform.TransformPoint(_controller.center);
    private float WorldRadius => _controller.radius * CapsuleScale;
    private float WorldHalfHeight => _controller.height * 0.5f * CapsuleScale;
    private const float ProbeReachSlack = 0.5f; // extra cast length beyond the capsule surface (scale-1 units)

    /// <summary>
    /// True if the collider belongs to ANY player avatar (self or a networked remote): avatars still
    /// collide physically, but another chameleon's body must never register as climbable.
    /// </summary>
    private static bool IsPlayerCollider(Collider c) => c.GetComponentInParent<PlayerCharacterController>();

    /// <summary>
    /// True if the collider is tagged as non-climbable (<see cref="noClimbTag"/>): it blocks the
    /// capsule but is never grabbed, re-probed onto, or treated as a ceiling. Empty tag disables.
    /// </summary>
    private bool IsNoClimb(Collider c) => !string.IsNullOrEmpty(noClimbTag) && c && c.CompareTag(noClimbTag);

    /// <summary>
    /// Probes from the capsule center toward the climbed surface (along -_wallNormal) for the
    /// current normal and the gap (clearance beyond the capsule surface). False = no hit.
    /// </summary>
    private bool ProbeWall(out Vector3 normal, out float gap)
    {
        Vector3 dir = -_wallNormal;
        float extent = CapsuleExtent(dir);
        float maxDist = extent + wallMaxOffset + ProbeReachSlack * CapsuleScale;

        if (NearestClimbHit(WorldCapsuleCenter, dir, maxDist, extent, ceilingOnly: false, out normal, out gap))
            return true;

        normal = _wallNormal;
        return false;
    }

    /// <summary>
    /// Capsule support distance from the center along a unit direction: the radius sideways,
    /// the half-height straight up/down, interpolated by the vertical component in between.
    /// </summary>
    private float CapsuleExtent(Vector3 dir)
    {
        float radius = WorldRadius;
        return radius + Mathf.Abs(dir.y) * (WorldHalfHeight - radius);
    }

    /// <summary>
    /// Probes straight up from the center for a ceiling overhead and its head clearance
    /// (top of the capsule to the surface). Only downward-facing (ceiling) hits count.
    /// </summary>
    private bool ProbeCeiling(out Vector3 normal, out float gap)
    {
        float half = WorldHalfHeight;
        float maxDist = half + wallMaxOffset + ProbeReachSlack * CapsuleScale;

        if (NearestClimbHit(WorldCapsuleCenter, Vector3.up, maxDist, half, ceilingOnly: true, out normal, out gap))
            return true;

        normal = Vector3.down;
        return false;
    }

    /// <summary>
    /// Sweeps a capsule-wide sphere along <paramref name="dir"/> and returns the nearest hit that a
    /// climb probe accepts (player avatars and no-climb surfaces never count;
    /// <paramref name="ceilingOnly"/> additionally rejects non-ceiling normals).
    /// <paramref name="gap"/> is the clearance beyond the capsule's support <paramref name="extent"/>.
    ///
    /// A swept sphere instead of a ray, for two reasons: its volume keeps contact with thin/narrow
    /// surfaces (boards) that a zero-width ray slips past, and its edge contacts return smoothly
    /// varying normals — a ray flips between adjacent face normals at an edge (cylinder facets,
    /// wall corners), snapping the body's facing back and forth. The cast starts one radius back so
    /// a surface at skin-width standoff can never be an (undetectable) initial overlap; with that
    /// backup, hit.distance measures from <paramref name="origin"/> like a plain ray would.
    /// </summary>
    private bool NearestClimbHit(Vector3 origin, Vector3 dir, float maxDist, float extent,
        bool ceilingOnly, out Vector3 normal, out float gap)
    {
        normal = Vector3.zero;
        gap = 0f;

        float radius = WorldRadius;
        int count = Physics.SphereCastNonAlloc(
            origin - dir * radius, radius, dir, _wallProbe, maxDist, ~0, QueryTriggerInteraction.Ignore);
        WarnIfProbeSaturated(count);

        float best = float.MaxValue;
        bool found = false;
        for (int i = 0; i < count; i++)
        {
            if (_wallProbe[i].distance <= 0f) // initial overlap; no usable point/normal
                continue;
            if (IsPlayerCollider(_wallProbe[i].collider) || IsNoClimb(_wallProbe[i].collider))
                continue;
            if (ceilingOnly && _wallProbe[i].normal.y >= CeilingNormalThreshold)
                continue;
            if (_wallProbe[i].distance < best)
            {
                best = _wallProbe[i].distance;
                normal = _wallProbe[i].normal;
                found = true;
            }
        }

        if (found)
            gap = Mathf.Max(0f, best - extent);
        return found;
    }

    private void WarnIfProbeSaturated(int hitCount)
    {
        if (hitCount != _wallProbe.Length || _wallProbeSaturated) return;
        _wallProbeSaturated = true;
        Debug.LogWarning($"PlayerCharacterController: climb probe buffer saturated ({hitCount}); the nearest surface may be missed.", this);
    }

    /// <summary>
    /// Pulls the character up and over the wall's top edge: phase 1 rises until the capsule clears
    /// the edge, phase 2 moves forward onto the surface, then exits. A short re-grab cooldown stops
    /// the passed edge from re-triggering a climb.
    /// </summary>
    private void MantleOverEdge(float dt)
    {
        _mantleTimer += dt;
        float speed = moveSpeed * wallMantleSpeedMultiplier;

        Vector3 forward = -_wallNormal;
        forward.y = 0f;
        forward = forward.sqrMagnitude > 1e-6f ? forward.normalized : transform.forward;

        if (!_mantleClearedFeet)
        {
            _controller.Move(Vector3.up * (speed * dt));
            if (!WallPresentAt(-WorldHalfHeight))
                _mantleClearedFeet = true;
        }
        else
        {
            _controller.Move(forward * (speed * dt));
            _mantleOverDist += speed * dt;
            if (_mantleOverDist >= WorldRadius * 2f + 0.15f * CapsuleScale || _controller.isGrounded)
            {
                _reentryCooldown = TopOutRegrabCooldown;
                ExitWallClimb();
                return;
            }
        }

        // Safety: never mantle indefinitely (e.g. blocked by other geometry).
        if (_mantleTimer >= 2f)
        {
            _reentryCooldown = TopOutRegrabCooldown;
            ExitWallClimb();
        }
    }

    /// <summary>
    /// The top-edge test that gates the mantle: a genuine top edge still has wall at the feet but is
    /// clear just above the center (that the center probe itself is clear is already known: it failed).
    /// The headroom check is the discriminator against a mid-face gap — there the wall continues
    /// above whatever the probe slipped through, so no mantle fires.
    /// </summary>
    private bool AtWallTopEdge()
    {
        return WallPresentAt(-WorldHalfHeight)
            && !WallPresentAt(WorldHalfHeight * 0.5f);
    }

    /// <summary>
    /// Volumetric wall-presence test toward -_wallNormal at a vertical offset from the capsule
    /// center (negative = below/feet, positive = above/headroom).
    /// </summary>
    private bool WallPresentAt(float upOffset)
    {
        Vector3 origin = WorldCapsuleCenter + Vector3.up * upOffset;
        float maxDist = WorldRadius + wallMaxOffset + ProbeReachSlack * CapsuleScale;
        return NearestClimbHit(origin, -_wallNormal, maxDist, 0f, ceilingOnly: false, out _, out _);
    }

    /// <summary>
    /// True when walkable ground (angle within the controller's slope limit) sits within step range
    /// below the capsule. Used to top out of a climb back onto solid ground without trusting
    /// isGrounded, which the standoff servo can falsify by holding the capsule just off the surface.
    /// No-climb surfaces still count: they can't be grabbed but can be stood on.
    /// </summary>
    private bool WalkableGroundBelow()
    {
        float radius = WorldRadius;
        float maxDist = (_controller.center.y + _controller.stepOffset) * CapsuleScale;

        int count = Physics.SphereCastNonAlloc(
            WorldCapsuleCenter + Vector3.up * radius, radius, Vector3.down,
            _wallProbe, maxDist, ~0, QueryTriggerInteraction.Ignore);
        WarnIfProbeSaturated(count);

        float best = float.MaxValue;
        Vector3 normal = Vector3.up;
        bool found = false;
        for (int i = 0; i < count; i++)
        {
            if (_wallProbe[i].distance <= 0f)
                continue;
            if (IsPlayerCollider(_wallProbe[i].collider))
                continue;
            if (_wallProbe[i].distance < best)
            {
                best = _wallProbe[i].distance;
                normal = _wallProbe[i].normal;
                found = true;
            }
        }
        return found && Vector3.Angle(normal, Vector3.up) <= _controller.slopeLimit;
    }

    /// <summary>
    /// Detaches at the top of a climbed wall/slope with an upward hop, so holding W carries the
    /// player over the lip instead of dropping back onto the face (which would re-grab and stall).
    /// The re-grab cooldown spans the hop, and the grab test only fires when not rising.
    /// </summary>
    private void TopOutDetach()
    {
        _reentryCooldown = TopOutRegrabCooldown;
        ExitWallClimb();
        if (wallTopOutBoost > 0f)
            _verticalVelocity = Mathf.Sqrt(wallTopOutBoost * -2f * gravity);
    }

    /// <summary>Leaves wall-climb mode and resets vertical velocity so the player falls cleanly.</summary>
    private void ExitWallClimb()
    {
        _isWallClimbing = false;
        _onCeiling = false;
        _lostContactTimer = 0f;
        _verticalVelocity = 0f;
        _climbVelocity = Vector3.zero;
        // Hand the current lean off to the residual so it eases home instead of snapping.
        _meshOffsetResidual = _wallOffset;
        _meshOffsetExitNormal = _wallNormal;
        _wallOffset = 0f;
        _wallYaw = 0f;
        _wallStrafeSign = 0;
        _wallClimbSign = 0;
        _offsetDragging = false;
        _climbLeftGround = false;
        _mantling = false;
        _mantleClearedFeet = false;
        _mantleOverDist = 0f;
        _mantleTimer = 0f;
    }

    /// <summary>
    /// Collects contact normals during Move: wall/ceiling contacts feed the wall-climb detector,
    /// the flattest upward contact becomes the ground normal.
    /// </summary>
    private void OnControllerColliderHit(ControllerColliderHit hit)
    {
        if (enableWallClimb && !IsNoClimb(hit.collider))
        {
            float angle = Vector3.Angle(hit.normal, Vector3.up);
            if (angle >= wallMinAngle)
            {
                _wallContactThisFrame = true;
                _wallNormalAccum += hit.normal;
            }
        }

        // Ignore near-vertical walls and ceilings for ground-normal collection.
        if (hit.normal.y <= 0.05f)
            return;

        // Keep the flattest (most supportive) contact seen this frame.
        if (!_groundNormalUpdated || hit.normal.y > _groundNormal.y)
        {
            _groundNormal = hit.normal;
            _groundNormalUpdated = true;
        }
    }
}