using ActionRPG.Input;
using UnityEngine;

namespace ActionRPG.Camera
{
    /// <summary>
    /// Third-person camera controller. Place this script on an empty pivot GameObject.
    /// Add a child GameObject for the physical camera and assign it to _cameraBoom.
    /// </summary>
    public class PlayerCameraController : MonoBehaviour
    {
        // ── References ─────────────────────────────────────────────────
        [Header("References")]
        [SerializeField] private PlayerInputReader _input;
        [SerializeField] private Transform _followTarget;
        [SerializeField] private UnityEngine.Camera _camera;
        [SerializeField] private Transform _cameraBoom;

        // ── Sensitivity & Inversion ────────────────────────────────────
        [Header("Sensitivity")]
        [SerializeField, Min(0.1f)] private float _mouseSensitivity = 5f;
        [SerializeField, Min(0.1f)] private float _gamepadSensitivity = 120f;
        [SerializeField] private bool _invertY = false;

        // ── Camera Position ────────────────────────────────────────────
        [Header("Position")]
        [SerializeField] private float _cameraDistance = 5f;
        [SerializeField] private float _heightOffset = 1.5f;
        [SerializeField] private float _horizontalOffset = 0.5f;
        [SerializeField] private float _tiltOffset = 0f;
        [SerializeField] private Vector2 _tiltBounds = new Vector2(-20f, 60f);

        // ── Lag ────────────────────────────────────────────────────────
        [Header("Lag")]
        [SerializeField, Min(0.01f)] private float _positionalLag = 0.05f;
        [SerializeField, Min(0.01f)] private float _rotationalLag = 0.05f;

        // ── Shoulder Switch ────────────────────────────────────────────
        [Header("Shoulder Switch")]
        [SerializeField] private bool _allowShoulderSwitch = true;
        [SerializeField] private float _shoulderSwitchSpeed = 8f;
        private float _currentHorizontalOffset;
        private bool _isRightShoulder = true;

        // ── Collision ──────────────────────────────────────────────────
        [Header("Collision")]
        [SerializeField] private bool _enableCollision = true;
        [SerializeField] private float _collisionRadius = 0.2f;
        [SerializeField] private LayerMask _collisionLayers;

        // ── Camera Shake ───────────────────────────────────────────────
        [Header("Camera Shake")]
        [SerializeField, Min(0f)] private float _shakeDecaySpeed = 3f;
        private float _shakeMagnitude;
        private float _shakeTimer;

        // ── Lock-On ────────────────────────────────────────────────────
        [Header("Lock-On")]
        [SerializeField] private bool _isLockedOn;
        [SerializeField] private Transform _lockOnTarget;
        [SerializeField, Min(0.1f)] private float _lockOnRotationSpeed = 8f;

        // ── Cursor ─────────────────────────────────────────────────────
        [Header("Cursor")]
        [SerializeField] private bool _hideCursor = true;

        // ── Internal state ─────────────────────────────────────────────
        private Vector3 _currentPosition;
        private float _yaw;
        private float _pitch;
        private float _currentYaw;
        private float _currentPitch;

        private void Start()
        {
            if (_hideCursor)
            {
                Cursor.visible = false;
                Cursor.lockState = CursorLockMode.Locked;
            }

            if (_followTarget != null)
            {
                transform.position = _followTarget.position;
                _yaw = transform.eulerAngles.y;
                _currentYaw = _yaw;
            }

            _currentHorizontalOffset = _horizontalOffset;
            ApplyBoomPosition();
        }

        private void LateUpdate()
        {
            if (_followTarget == null) return;

            HandleRotation();
            HandlePositionalFollow();
            HandleShoulderOffset();
            HandleCollision();
            HandleShake();
            ApplyBoomPosition();
        }

        // ── Rotation ───────────────────────────────────────────────────

        private void HandleRotation()
        {
            if (_isLockedOn && _lockOnTarget != null)
            {
                // Smoothly rotate to face the lock-on target
                Vector3 toTarget = _lockOnTarget.position - transform.position;
                toTarget.y = 0f;
                if (toTarget != Vector3.zero)
                {
                    float targetYaw = Quaternion.LookRotation(toTarget).eulerAngles.y;
                    _yaw = Mathf.LerpAngle(_currentYaw, targetYaw, _lockOnRotationSpeed * Time.deltaTime);
                }

                // Keep pitch level when locked on
                _pitch = Mathf.Lerp(_currentPitch, 0f, _lockOnRotationSpeed * Time.deltaTime);
            }
            else
            {
                Vector2 look = _input.LookInput;
                float invertSign = _invertY ? 1f : -1f;

                // Detect gamepad (larger raw values) vs mouse
                bool isGamepad = look.magnitude > 1f;
                float sensitivity = isGamepad ? _gamepadSensitivity * Time.deltaTime : _mouseSensitivity;

                _yaw   += look.x * sensitivity;
                _pitch += look.y * sensitivity * invertSign;
                _pitch  = Mathf.Clamp(_pitch, _tiltBounds.x, _tiltBounds.y);
            }

            _currentYaw   = Mathf.LerpAngle(_currentYaw, _yaw, _rotationalLag > 0 ? Time.deltaTime / _rotationalLag : 1f);
            _currentPitch = Mathf.LerpAngle(_currentPitch, _pitch, _rotationalLag > 0 ? Time.deltaTime / _rotationalLag : 1f);

            transform.rotation = Quaternion.Euler(_currentPitch + _tiltOffset, _currentYaw, 0f);
        }

        // ── Positional Follow ──────────────────────────────────────────

        private void HandlePositionalFollow()
        {
            Vector3 targetPos = _followTarget.position + Vector3.up * _heightOffset;
            _currentPosition = Vector3.Lerp(_currentPosition == Vector3.zero ? targetPos : _currentPosition,
                targetPos,
                _positionalLag > 0 ? Time.deltaTime / _positionalLag : 1f);

            transform.position = _currentPosition;
        }

        // ── Shoulder Switch ────────────────────────────────────────────

        private void HandleShoulderOffset()
        {
            float targetOffset = _isRightShoulder ? _horizontalOffset : -_horizontalOffset;
            _currentHorizontalOffset = Mathf.Lerp(_currentHorizontalOffset, targetOffset, _shoulderSwitchSpeed * Time.deltaTime);
        }

        // ── Collision ──────────────────────────────────────────────────

        private void HandleCollision()
        {
            if (!_enableCollision || _cameraBoom == null) return;

            Vector3 origin = transform.position;
            Vector3 dir    = _cameraBoom.position - origin;
            float   maxDist = _cameraDistance;

            if (Physics.SphereCast(origin, _collisionRadius, dir.normalized, out RaycastHit hit, maxDist, _collisionLayers))
            {
                float adjustedDistance = Mathf.Clamp(hit.distance - _collisionRadius, 0.5f, maxDist);
                _cameraBoom.localPosition = new Vector3(_currentHorizontalOffset, 0f, -adjustedDistance);
            }
        }

        // ── Camera Shake ───────────────────────────────────────────────

        private void HandleShake()
        {
            if (_shakeTimer > 0f)
            {
                _shakeTimer -= Time.deltaTime * _shakeDecaySpeed;
                float shake = Mathf.Lerp(0f, _shakeMagnitude, _shakeTimer);
                _cameraBoom.localPosition += (Vector3)Random.insideUnitCircle * shake;
            }
            else
            {
                _shakeTimer = 0f;
            }
        }

        // ── Boom Position ──────────────────────────────────────────────

        private void ApplyBoomPosition()
        {
            if (_cameraBoom == null) return;
            _cameraBoom.localPosition = new Vector3(_currentHorizontalOffset, 0f, -_cameraDistance);
            _cameraBoom.localEulerAngles = Vector3.zero;
        }

        // ── Public API ─────────────────────────────────────────────────

        /// <summary>Enables or disables lock-on to a target.</summary>
        public void SetLockOn(bool enabled, Transform target = null)
        {
            _isLockedOn  = enabled;
            _lockOnTarget = target != null ? target : _lockOnTarget;
        }

        /// <summary>Switches the camera between left and right shoulder.</summary>
        public void SwitchShoulder()
        {
            if (!_allowShoulderSwitch) return;
            _isRightShoulder = !_isRightShoulder;
        }

        /// <summary>Triggers a camera shake effect.</summary>
        /// <param name="magnitude">Strength of the shake.</param>
        /// <param name="duration">Duration in seconds (controls decay speed).</param>
        public void Shake(float magnitude, float duration = 1f)
        {
            _shakeMagnitude = magnitude;
            _shakeTimer     = duration;
        }

        /// <summary>Returns the camera's forward vector with Y zeroed and normalised. Use for movement direction.</summary>
        public Vector3 CameraForwardFlat => new Vector3(_camera.transform.forward.x, 0f, _camera.transform.forward.z).normalized;

        /// <summary>Returns the camera's right vector with Y zeroed and normalised.</summary>
        public Vector3 CameraRightFlat => new Vector3(_camera.transform.right.x, 0f, _camera.transform.right.z).normalized;

        /// <summary>Returns the camera's current yaw in world space.</summary>
        public float CameraYaw => _currentYaw;

        private void OnDrawGizmosSelected()
        {
            if (_cameraBoom == null) return;
            Gizmos.color = Color.cyan;
            Gizmos.DrawWireSphere(_cameraBoom.position, _collisionRadius);
        }
    }
}