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/edges, and a wall-climb mode.
///
/// Wall-climb (entered by pushing the move input into a wall): W/S climb straight up/down the
/// wall at a constant speed, A/D strafe left/right relative to the camera, and the body always
/// faces the wall. Holding the left mouse button and dragging up/down leans the visual mesh out
/// of or into the wall (only the model + its paint collider move; the capsule stays put, so the
/// lean can sink into the wall); holding the right mouse button and dragging left/right turns the
/// body. Either pauses the camera orbit; the lean offset eases back to zero while moving, the turn
/// is held until leaving the wall.
/// On leaving, the body eases back to its movement direction. Jumping detaches and works
/// normally; re-grab is blocked while rising and resumes once falling and pushing into a wall.
/// Reaching the top edge mantles the character over onto the surface.
///
/// Ceiling-climb shares the same mode: entered by jumping up into a ceiling or by climbing a
/// wall up into an overhang. The body stays upright and clings to the ceiling, moving in the
/// horizontal plane camera-relative (like on the ground). Jump (or reaching a ceiling edge)
/// lets go and drops.
///
/// On the ground the same mouse scheme fine-tunes a pose without moving the capsule: holding the
/// left mouse button and dragging up/down raises/lowers the visual mesh, holding the right mouse
/// button and dragging left/right turns the body. The raise eases back while walking and holds while
/// standing; the turn holds until movement re-aims the body. Both pause the camera orbit while held.
///
/// Named PlayerCharacterController to avoid a clash with Unity.VisualScripting's
/// example "PlayerController".
/// </summary>
[RequireComponent(typeof(CharacterController))]
[DisallowMultipleComponent]
public partial 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;

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

    /// <summary>
    /// True while the player is idle (under control and essentially still): standing on the floor
    /// below the run threshold, or attached to a wall/ceiling with no climb input. 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 (ground, air, wall, or ceiling).</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 actually moving above the run threshold (the ground-locomotion state).
    /// Airborne, wall/ceiling, and standing still all read false. This is the same signal that drives
    /// the run bool, exposed so the pose system can pick its walk/run locomotion clips.
    /// </summary>
    public bool IsMovingOnGround => _movingOnGround;

    /// <summary>
    /// Set by <see cref="PlayerPoseController"/> while a pose Playable graph owns the Animator output.
    /// While set, the run-bool is not poked: it would be moot (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 — with the humanoid rig the Animator sits on this same node, so it
    /// lands in the reset subtree and would otherwise be snapped back to base every frame, wiping the offset.
    /// </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 (see <see cref="BaseCapsuleCenterY"/>).</summary>
    public float BaseCapsuleRadius { get; private set; }

    /// <summary>Authored CharacterController capsule height, captured in Awake (see <see cref="BaseCapsuleCenterY"/>).</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 float _verticalVelocity;
    private Vector3 _horizontalVelocity;  // smoothed horizontal move velocity (accel/decel ramp)
    private bool _sprinting;              // sprint key state this frame (exposed via IsSprinting)
    private bool _isIdle;                 // snapshot: player essentially still this frame (exposed via IsIdle)
    private bool _movingOnGround;         // snapshot: grounded & moving above the run threshold (exposed via IsMovingOnGround)
    private float _groundOffset;          // signed vertical mesh raise from the ground mouse pose-adjust (+ up / - down); folded into SetMeshLean

    // Ground contact normal from the latest Move (for slope sliding).
    private Vector3 _groundNormal = Vector3.up;
    private bool _groundNormalUpdated;
    private float _slideSpeed;

    // Wall-climb state. A climb surface counts as a ceiling (horizontal-crawl model) rather
    // than a wall (up/down model) once its normal points down past this threshold (~>120 deg
    // from up); between that and wallMinAngle it is treated as a wall.
    private const float CeilingNormalThreshold = -0.5f;
    // Hysteresis band around the threshold: in the inner wall/ceiling corner the capsule touches
    // both surfaces, so the per-frame contact normal mixes horizontal (wall) and downward (ceiling)
    // and its y crosses -0.5 back and forth -- flipping the climb mode and snapping the body's yaw
    // between "face the wall" and "face the move direction". Latch the class and only flip when the
    // normal is unambiguously past one edge of the band.
    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; see thresholds above)
    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): + = out from the wall, - = into it; moves only the model, not the capsule
    private float _wallYaw;               // body yaw offset from facing the wall (mouse drag); held until leaving
    private int _wallStrafeSign;          // latched sideways direction (camera picks it once per strafe); 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 (enables ground-detach)
    private Vector3 _meshBaseLocalPos;    // meshOffsetTarget's authored local position; the lean offset is applied relative to this
    private Vector3 _cameraTargetBaseLocalPos; // cameraTarget's authored local position; the pose/ceiling camera offset is applied relative to this
    private float _cameraYOffset;         // last camera-target local-up offset written (cached so an unchanged value skips the transform write)
    private float _meshOffsetResidual;    // leftover mesh lean still easing back to 0 after leaving the wall (no longer climbing)
    private Vector3 _meshOffsetExitNormal; // wall normal latched at exit; the residual eases along it (live _wallNormal may shift on stray contact)
    private readonly RaycastHit[] _wallProbe = new RaycastHit[8];

    // Mantle (top-out) state.
    private const float TopOutRegrabCooldown = 0.3f; // blocks re-grab right after any top-out so holding W tops out cleanly instead of 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;       // blocks re-grabbing right after topping out

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

        // Resolve the model root to offset: walk up from the skinned mesh to the topmost node still
        // under this transform, so it 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()
    {
        float h = 0f, v = 0f;
        bool jumpPressed = false;
        bool sprinting = false;

        // Skip input when control is disabled (e.g. paint mode); gravity and
        // grounding below still run so the player stays planted.
        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)
        {
            // Project the camera axes onto the ground plane so movement stays horizontal.
            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: the per-frame contact blend mixes ceiling
        // and wall normals in an inner corner (e.g. ~(0,-0.97,-0.26)), which would fight the
        // probed surface and flip the wall/ceiling classification frame to frame. Reset the
        // accumulators regardless (OnControllerColliderHit refills them during Move).
        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 (e.g. paint mode): keep the
            // grip, no movement or gravity, 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; // drop ground momentum so resuming starts from rest
            _isIdle = ControlEnabled && (h * h + v * v) <= 1e-4f; // attached & no climb input = holding a pose
            _movingOnGround = false;            // on a wall/ceiling, never ground locomotion
            return;
        }

        // Ground pose-adjust (mouse): left button + vertical drag raises/lowers the mesh, right
        // button + horizontal drag turns the body -- the wall scheme mirrored to the ground. Either
        // pauses the camera orbit so the same drag isn't also spent orbiting. 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;

        // Glide the leftover wall lean home and re-apply the composed mesh offset (residual lean +
        // ground raise + pose y-offset) in this frame's single write of meshOffsetTarget.
        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
            && _controller.isGrounded
            && slopeAngle > _controller.slopeLimit + 0.01f;

        if (_controller.isGrounded)
        {
            if (_verticalVelocity < 0f)
                _verticalVelocity = groundedStickVelocity;

            // No jumping off a slope too steep to stand on.
            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; // reduced steering while sliding
        }
        else
        {
            _slideSpeed = 0f;
        }

        float currentSpeed = sprinting ? moveSpeed * sprintSpeedMultiplier : moveSpeed;
        // Ease horizontal velocity toward the target so movement accelerates/decelerates
        // instead of snapping. Accel while there is input, decel when it eases off.
        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;
        // fall back to "up" if nothing was hit.
        _groundNormalUpdated = false;
        _controller.Move(velocity * Time.deltaTime);
        if (!_groundNormalUpdated)
            _groundNormal = Vector3.up;

        // Face the movement direction, unless the right-button turn is actively steering the body.
        if (rotateTowardMovement && !groundYawDrag && moveDir.sqrMagnitude > 0.0001f)
        {
            Quaternion target = Quaternion.LookRotation(moveDir, Vector3.up);
            transform.rotation = Quaternion.RotateTowards(
                transform.rotation, target, rotationSpeed * Time.deltaTime);
        }

        // Run animation: only while grounded and actually moving (airborne/sliding-blocked = idle).
        // 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; // standing still on the floor
    }

    /// <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)
        {
            if (_isWallClimbing)
                ExitWallClimb();
            return;
        }

        // Decide whether the contacted surface is being pushed into. A wall is grabbed by
        // pushing the move input horizontally into it while not rising (mere contact, e.g.
        // standing at a wall's base, must not grab). A ceiling can't be pushed into
        // horizontally, so it is grabbed by rising up into it (jumping up against 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 (e.g. paint mode) so switching modes never drops us off the surface.
        // 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;       // drop any ground pose-adjust raise so it doesn't ride onto the wall
            _meshOffsetResidual = 0f; // fresh grab: the climb path owns the mesh, drop any leftover ease
            _wallYaw = 0f;
            _wallStrafeSign = 0;
            _climbLeftGround = false;
        }
    }

    /// <summary>
    /// Movement while climbing, for both walls and ceilings (distinguished by the surface
    /// normal). On a WALL: W/S climb straight up/down at a constant speed (camera pitch never
    /// tilts them), A/D strafe left/right relative to the camera, the body faces the wall, the
    /// left mouse button + vertical drag leans the mesh out of / into the wall via
    /// <see cref="_wallOffset"/> (capsule stays put), and the right
    /// mouse button + horizontal drag turns the body via <see cref="_wallYaw"/>. On a
    /// CEILING: the body stays upright and moves WASD camera-relative in the horizontal plane
    /// (like on the ground), facing the move direction unless the right mouse button + horizontal
    /// drag turns it; the lean-out drag pulls down off the ceiling. Surface normal and gap are
    /// re-measured each frame; reaching a wall's top edge
    /// mantles, climbing a wall up 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;

        // Jump detaches. Off a wall it pushes straight up; off a ceiling it just lets go and
        // drops. Re-grab stays blocked appropriately by UpdateWallClimbState's push-in test.
        if (jumpPressed)
        {
            ExitWallClimb();
            _verticalVelocity = onCeiling ? 0f : Mathf.Sqrt(jumpHeight * -2f * gravity);
            return;
        }

        // Wall->ceiling hand-off: while climbing up a wall into an overhang, switch to the
        // ceiling right above the head instead of trying to mantle over a (non-existent) top.
        if (!onCeiling && v > 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 (ProbeCeiling), NOT along -_wallNormal: the ceiling normal tilts a
        // little toward the wall in an inner corner, so the -_wallNormal ray would clip the wall
        // and demote us to "wall" — then the hand-off re-promotes next frame, flipping the body's
        // facing ~9 deg every frame (the corner twitch). Stay latched on the ceiling until it is
        // genuinely gone overhead; only then fall back to the wall probe.
        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 (no
        // longer steep enough to be a wall). Hand back to normal grounded movement instead of
        // clinging to a "wall" that is really just ground now.
        if (found && !onCeiling && _climbLeftGround
            && Vector3.Angle(_wallNormal, Vector3.up) < wallMinAngle)
        {
            // Hop over the lip only when actually moving up onto the flattened face (a real
            // top-out); if we reached it going down, just step off cleanly with no hop.
            if (v > 0f) TopOutDetach();
            else ExitWallClimb();
            return;
        }

        Vector3 alongSurface;
        if (onCeiling)
        {
            // Crawl across the ceiling in the horizontal plane, camera-relative (moveDir is
            // already the ground-projected camera input); project onto the ceiling for safety.
            alongSurface = Vector3.ProjectOnPlane(moveDir, _wallNormal);
        }
        else
        {
            // W/S climb straight up/down the wall at a constant speed (camera pitch never tilts
            // them). Strafe along the wall's own horizontal tangent, not the live camera-right
            // vector: feeding camera-right in here coupled movement to the orbit camera's
            // per-frame re-aim and jittered sideways motion. The camera only picks the sign.
            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 it every frame flips wallRight while rounding a curved (cylindrical)
            // wall: exactly at 90 deg to the camera the dot crosses zero, so the sideways input
            // inverts frame-to-frame and you lock there, jittering back and forth. Latching keeps
            // a strafe continuous around the curve; it resets when the strafe input releases so
            // the next one re-syncs to the camera.
            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 * v + wallRight * h;
        }
        if (alongSurface.sqrMagnitude > 1f) alongSurface.Normalize();
        bool hasMoveInput = (h * h + v * v) > 1e-4f;

        if (!found)
        {
            // Wall only: losing the center ray while climbing up the face = top edge → mantle.
            if (!onCeiling && alongSurface.y > 0f && WallInFront(WorldHalfHeight))
            {
                _mantling = true;
                _mantleClearedFeet = false;
                _mantleOverDist = 0f;
                _mantleTimer = 0f;
                MantleOverEdge(dt);
                return;
            }

            // Surface genuinely gone (incl. crawling off a ceiling edge): leave after grace,
            // dropping into normal gravity.
            _lostContactTimer += dt;
            if (_lostContactTimer >= wallExitGrace)
            {
                ExitWallClimb();
                return;
            }
        }

        // Left button + vertical drag sets the lean offset (mouse up = out from the surface, mouse
        // down = into it; the offset is signed and moves only the visual mesh, so it can sink into
        // the wall where the capsule can't); right button + horizontal drag turns the body. The
        // offset eases back to zero while moving and never detaches. On a WALL the turn is a held
        // yaw offset from the wall normal (kept until leaving); on a CEILING the body is free like
        // on the ground, so the drag rotates the transform directly. Either drag pauses the orbit.
        bool offsetDrag = found && IsLeftMouseHeld();
        bool yawDrag = found && IsRightMouseHeld();
        if (offsetDrag || yawDrag)
        {
            _offsetDragging = true;
            Vector2 drag = 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);
        }
        ApplyMeshOffset(_wallOffset);

        float climbSpeed = moveSpeed * wallClimbSpeedMultiplier;
        if (sprinting) climbSpeed *= sprintSpeedMultiplier;
        Vector3 velocity = Vector3.zero;
        if (alongSurface.sqrMagnitude > 1e-6f)
            velocity += alongSurface.normalized * climbSpeed;
        if (found)
        {
            // Smoothly hold the capsule one skin-width off the surface (flush): the lean offset no
            // longer moves the capsule (only the visual mesh), so it always rests against the wall.
            // The controller's depenetration never fights back, so there's no buzz and no quantizing
            // deadzone is needed. Exponential follow keeps it framerate-stable; 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 back to normal grounded movement. The top-out hop
        // (carry over the lip) fires ONLY when topping out upward over an edge (v > 0). Arriving
        // at the floor by descending, OR pressing down/away (S, v < 0) at the wall's base while
        // grounded, just lets go cleanly with no hop -- the latter is the only detach path that
        // doesn't require having left the ground first, so a wall grabbed at its base can be
        // released by pressing away. We test walkable ground under the feet rather than trusting
        // isGrounded: the standoff correction can lift the capsule just off the surface, so at a
        // slope's top isGrounded stays false and the old check never fired.
        bool onWalkableGround = _controller.isGrounded || WalkableGroundBelow();
        if (!onWalkableGround)
        {
            _climbLeftGround = true;
        }
        else if (_climbLeftGround && v > 0f)
        {
            TopOutDetach(); // topped out upward onto walkable ground: hop over the lip (holding W carries on)
            return;
        }
        else if (_climbLeftGround || v < 0f)
        {
            ExitWallClimb(); // descended to the floor, or pulling down/away at the base: let go, no hop
            return;
        }

        if (rotateTowardMovement)
        {
            if (onCeiling)
            {
                // Stay upright and face the horizontal move direction, like on the ground -- unless
                // the right-button turn is actively steering the body (then the manual yaw holds).
                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.
                // On leaving, the ground rotation eases the body back to its movement direction.
                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 with hysteresis on the surface normal's
    /// downward tilt. In the inner corner the live normal jitters across the single threshold; the
    /// band keeps the climb mode (and the body yaw it drives) from flipping frame to frame.
    /// </summary>
    private void UpdateCeilingClass()
    {
        if (_onCeiling)
        {
            if (_wallNormal.y > CeilingExitThreshold) _onCeiling = false;
        }
        else if (_wallNormal.y < CeilingEnterThreshold)
        {
            _onCeiling = true;
        }
    }

    /// <summary>
    /// Offsets only the visual model (mesh + its baked paint collider) along the wall normal by the
    /// given signed distance (+ = out from the wall, - = into it), relative to the model's authored
    /// local position. The CharacterController capsule is untouched, so the lean can sink into the
    /// wall where the capsule would be blocked. Applied in the player's local space so it tracks the
    /// body yaw; offset 0 restores the authored pose.
    /// </summary>
    private void ApplyMeshOffset(float offset) => SetMeshLean(_wallNormal, offset);

    /// <summary>
    /// Places the visual model at the given signed lean along <paramref name="dir"/> (world space),
    /// relative to its authored local pose. Local-space conversion tracks the live body yaw.
    /// </summary>
    private void SetMeshLean(Vector3 dir, float offset)
    {
        if (!meshOffsetTarget) return;
        Vector3 worldOffset = dir * offset;
        meshOffsetTarget.localPosition = _meshBaseLocalPos
            + transform.InverseTransformVector(worldOffset)
            + Vector3.up * _groundOffset; // ground mouse raise (0 unless in use)
    }

    /// <summary>
    /// Re-applies the resting mesh offset every non-climbing frame in a single write of
    /// <see cref="meshOffsetTarget"/>: eases the leftover wall lean back toward the authored pose
    /// (latched exit normal) while composing in the ground mouse raise and any pose y-offset. Writing
    /// unconditionally (even at rest) keeps this the sole owner of the offset transform, so a held
    /// ground raise stays applied after the residual has reached zero. Offset 0 restores the pose.
    /// </summary>
    private void EaseMeshOffsetToRest(float dt)
    {
        if (_meshOffsetResidual != 0f)
            _meshOffsetResidual = Mathf.MoveTowards(_meshOffsetResidual, 0f, wallOffsetReturnSpeed * dt);
        SetMeshLean(_meshOffsetExitNormal, _meshOffsetResidual);
    }

    /// <summary>
    /// Ground pose-adjust via the mouse, mirroring the wall-climb scheme: holding the LEFT button and
    /// dragging up/down raises/lowers the visual mesh vertically (<see cref="_groundOffset"/>, capsule
    /// untouched), holding the RIGHT button and dragging left/right turns the body (world-up yaw). The
    /// raise eases back to the authored height while moving and holds while standing or dragging; the
    /// turn persists until movement re-aims the body. Returns true while a right-button turn is active
    /// so the caller skips auto-rotate-toward-movement that frame. Call site gates on ControlEnabled so
    /// paint mode keeps the left button for painting.
    /// </summary>
    private bool HandleGroundPoseAdjust(float h, float v, float dt)
    {
        _offsetDragging = false;
        
        bool offsetDrag = IsLeftMouseHeld();
        bool yawDrag = IsRightMouseHeld();
        bool hasMoveInput = (h * h + v * v) > 1e-4f;

        if (offsetDrag || yawDrag)
        {
            _offsetDragging = true;
            Vector2 drag = 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 (center Y, radius, height) to the active pose's dimensions,
    /// driven by <see cref="PlayerPoseController"/> so a low pose can fit where the default standing capsule
    /// is too tall. Only the collision capsule changes — the visual model and camera target are untouched.
    /// 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 (the ThirdPersonCamera's follow/look target) at the given local-up
    /// offset relative to its authored local position, without moving the body. Driven by
    /// <see cref="PlayerPoseController"/> with the active pose's camera y-offset plus the ceiling offset;
    /// 0 restores the authored target 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 CharacterController's serialized center/radius/height are authored at the player's base
    // (scale-1) size; transform.localScale resizes the ACTUAL collision capsule via lossyScale but
    // leaves those serialized numbers untouched. Every climb probe below raycasts in WORLD space, so
    // it must use the scaled (world) capsule dimensions and scale its world-distance paddings too --
    // otherwise the wall grab range, head-to-ceiling gap and mantle distance are all measured at the
    // authored size on a shrunk/grown player (PlayerScaler scales the tunables but not these probes).
    // 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 ray length beyond the capsule surface (scale-1 units)

    /// <summary>
    /// Raycasts from the character center toward the surface (along -_wallNormal) to find the
    /// current normal and the gap (surface clearance) to it. The capsule's support distance
    /// along the probe direction is the radius sideways but up to the half-height vertically,
    /// so the gap is correct for ceilings too. Our own colliders are skipped. False = no hit.
    /// </summary>
    private bool ProbeWall(out Vector3 normal, out float gap)
    {
        normal = _wallNormal;
        gap = 0f;

        Vector3 origin = WorldCapsuleCenter;
        Vector3 dir = -_wallNormal;
        float extent = CapsuleExtent(dir);
        float maxDist = extent + wallMaxOffset + ProbeReachSlack * CapsuleScale;

        int count = Physics.RaycastNonAlloc(
            origin, dir, _wallProbe, maxDist, ~0, QueryTriggerInteraction.Ignore);

        float best = float.MaxValue;
        bool found = false;
        for (int i = 0; i < count; i++)
        {
            if (_wallProbe[i].collider.transform.IsChildOf(transform)) // skip our own colliders
                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;
    }

    /// <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>
    /// Raycasts straight up from the center to find 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)
    {
        normal = Vector3.down;
        gap = 0f;

        Vector3 origin = WorldCapsuleCenter;
        float half = WorldHalfHeight;
        float maxDist = half + wallMaxOffset + ProbeReachSlack * CapsuleScale;

        int count = Physics.RaycastNonAlloc(
            origin, Vector3.up, _wallProbe, maxDist, ~0, QueryTriggerInteraction.Ignore);

        float best = float.MaxValue;
        bool found = false;
        for (int i = 0; i < count; i++)
        {
            if (_wallProbe[i].collider.transform.IsChildOf(transform))
                continue;
            if (_wallProbe[i].normal.y >= CeilingNormalThreshold) // not a ceiling
                continue;
            if (_wallProbe[i].distance < best)
            {
                best = _wallProbe[i].distance;
                normal = _wallProbe[i].normal;
                found = true;
            }
        }

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

    /// <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)
        {
            // Phase 1: climb straight up until no wall is left in front of the feet.
            _controller.Move(Vector3.up * (speed * dt));
            if (!WallInFront(WorldHalfHeight))
                _mantleClearedFeet = true;
        }
        else
        {
            // Phase 2: move forward onto the top surface, then finish.
            _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>
    /// Horizontal ray toward the wall from a point below the center. Distinguishes a
    /// top edge (wall still present lower down) from the wall being truly gone.
    /// </summary>
    private bool WallInFront(float downOffset)
    {
        Vector3 origin = WorldCapsuleCenter - Vector3.up * downOffset;
        float maxDist = WorldRadius + wallMaxOffset + ProbeReachSlack * CapsuleScale;

        int count = Physics.RaycastNonAlloc(
            origin, -_wallNormal, _wallProbe, maxDist, ~0, QueryTriggerInteraction.Ignore);
        for (int i = 0; i < count; i++)
        {
            if (_wallProbe[i].collider.transform.IsChildOf(transform))
                continue;
            return true;
        }
        return false;
    }

    /// <summary>
    /// Short downward ray from the capsule center: true when walkable ground (angle within the
    /// controller's slope limit) sits within step range below the feet. Used to top out of a
    /// climb back onto solid ground without trusting isGrounded, which the standoff correction
    /// can falsify by lifting the capsule slightly off the surface.
    /// </summary>
    private bool WalkableGroundBelow()
    {
        Vector3 origin = WorldCapsuleCenter;
        float maxDist = (_controller.center.y + _controller.stepOffset) * CapsuleScale;

        int count = Physics.RaycastNonAlloc(
            origin, Vector3.down, _wallProbe, maxDist, ~0, QueryTriggerInteraction.Ignore);

        float best = float.MaxValue;
        Vector3 normal = Vector3.up;
        bool found = false;
        for (int i = 0; i < count; i++)
        {
            if (_wallProbe[i].collider.transform.IsChildOf(transform))
                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 onto the ledge 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 (<see cref="UpdateWallClimbState"/>), so the hop is never cut short.
    /// </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;
        // Hand the current lean off to the residual so it eases home (EaseMeshOffsetToRest)
        // instead of snapping; latch the normal since the live one may shift after detaching.
        _meshOffsetResidual = _wallOffset;
        _meshOffsetExitNormal = _wallNormal;
        _wallOffset = 0f;
        _wallYaw = 0f;
        _wallStrafeSign = 0;
        _offsetDragging = false;
        _climbLeftGround = false;
        _mantling = false;
        _mantleClearedFeet = false;
        _mantleOverDist = 0f;
        _mantleTimer = 0f;
    }

    bool IsLeftMouseHeld()
    {
#if ENABLE_INPUT_SYSTEM
        return Mouse.current != null && Mouse.current.leftButton.isPressed;
#else
        return Input.GetMouseButton(0);
#endif
    }

    bool IsRightMouseHeld()
    {
#if ENABLE_INPUT_SYSTEM
        return Mouse.current != null && Mouse.current.rightButton.isPressed;
#else
        return Input.GetMouseButton(1);
#endif
    }

    Vector2 ReadMouseDelta()
    {
#if ENABLE_INPUT_SYSTEM
        return Mouse.current != null ? Mouse.current.delta.ReadValue() : Vector2.zero;
#else
        return new Vector2(Input.GetAxisRaw("Mouse X"), Input.GetAxisRaw("Mouse Y")) * 10f;
#endif
    }

    /// <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)
        {
            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;
        }
    }
}