using Unity.Cinemachine;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.Events;

namespace BrewMonster
{
    public class CameraController : MonoBehaviour, IPointerDownHandler, IPointerUpHandler, IDragHandler
    {
        public static CameraController Instance;
        [SerializeField] private CinemachineCamera _cinemachineCamera;
        [SerializeField] private CinemachineOrbitalFollow orbital;
        private bool fingerDown = false;
        [SerializeField, Min(0f)] private float dragDeadZone = 10f;
        [SerializeField] private float horizontalRotationPerScreen = 60f;
        [SerializeField] private float verticalRotationPerScreen = 500f;
        [SerializeField, HideInInspector] private bool _migratedDeadZoneToNormalized;

        [Header("Lock view")]
        [Tooltip("When locked: no zoom; drag only orbits around world Y (horizontal axis).")]
        [SerializeField] private bool _lockView;
        [SerializeField] private UnityEvent<bool> onViewLockChanged;

        [Header("Zoom (orbit scale)")]
        [Tooltip("RadialAxis scales camera distance: effective distance = Orbital Follow Radius × this value.")]
        [SerializeField] private bool enableZoom = true;
        [SerializeField] private float orbitScaleMin = 0.5f;
        [SerializeField] private float orbitScaleMax = 2f;
        [SerializeField] private float defaultOrbitScale = 1f;
        [SerializeField] private float zoomSensitivityScroll = 0.15f;
        [SerializeField] private float zoomSensitivityPinch = 0.004f;

        private float _lastPinchDistance;
        private bool _pinchZoomActive;
        private int _touchCount = 0;

        public CinemachineOrbitalFollow Orbital { get => orbital;}

        public bool ViewLocked => _lockView;

        public void SetViewLocked(bool locked)
        {
            if (_lockView == locked)
            {
                return;
            }

            _lockView = locked;
            onViewLockChanged?.Invoke(_lockView);
        }

        public void ToggleViewLocked()
        {
            SetViewLocked(!_lockView);
        }

        private bool CanApplyZoom => enableZoom && !_lockView;

        void OnEnable()
        {
            Instance = this;
            MigrateLegacyDeadZone();
        }

        private void Start()
        {
            SyncRadialAxisRange();
        }

        public void OnDrag(PointerEventData eventData)
        {
            if (!fingerDown || orbital == null)
            {
                return;
            }

            float screenReference = Mathf.Max(1f, Mathf.Min(Screen.width, Screen.height));
            Vector2 normalizedDelta = eventData.delta / screenReference;
            float normalizedDeadZone = Mathf.Max(0.0001f, dragDeadZone);

            if (normalizedDelta.sqrMagnitude >= normalizedDeadZone * normalizedDeadZone)
            {
                orbital.HorizontalAxis.Value += normalizedDelta.x * horizontalRotationPerScreen;
                if (!_lockView)
                {
                    orbital.VerticalAxis.Value -= normalizedDelta.y * verticalRotationPerScreen;
                    orbital.VerticalAxis.Value = Mathf.Clamp(orbital.VerticalAxis.Value, -360f, 360f);
                }
            }
        }

        public void OnPointerDown(PointerEventData eventData)
        {
            fingerDown = true;
            if(_touchCount < 2)
            {
                _touchCount++;
            }
        }

        public void OnPointerUp(PointerEventData eventData)
        {
            fingerDown = false;
            if(_touchCount > 0)
            {
                _touchCount--;
            }
        }

        private void OnValidate()
        {
            MigrateLegacyDeadZone();
            orbitScaleMin = Mathf.Max(0.01f, orbitScaleMin);
            orbitScaleMax = Mathf.Max(orbitScaleMin, orbitScaleMax);
            defaultOrbitScale = Mathf.Clamp(defaultOrbitScale, orbitScaleMin, orbitScaleMax);
            SyncRadialAxisRange();
        }

        /// <summary> Keeps Cinemachine RadialAxis range in sync with serialized min/max. </summary>
        private void SyncRadialAxisRange()
        {
            if (orbital == null)
            {
                return;
            }

            float min = Mathf.Min(orbitScaleMin, orbitScaleMax);
            float max = Mathf.Max(orbitScaleMin, orbitScaleMax);
            var radial = orbital.RadialAxis;
            var range = radial.Range;
            range.x = min;
            range.y = max;
            radial.Range = range;
            radial.Value = radial.ClampValue(radial.Value);
            orbital.RadialAxis = radial;
        }

        private void ResetFollowCameraAxes()
        {
            if (orbital == null)
            {
                return;
            }

            orbital.HorizontalAxis.Value = 208;
            orbital.VerticalAxis.Value = -268;
            SyncRadialAxisRange();
            var radial = orbital.RadialAxis;
            radial.Value = radial.ClampValue(defaultOrbitScale);
            orbital.RadialAxis = radial;
        }

        private void ApplyRadialZoomDelta(float delta)
        {
            if (!CanApplyZoom || orbital == null || Mathf.Abs(delta) < 1e-6f)
            {
                return;
            }

            var radial = orbital.RadialAxis;
            radial.Value = radial.ClampValue(radial.Value + delta);
            orbital.RadialAxis = radial;
        }

        private void UpdatePinchZoom()
        {
            if (!CanApplyZoom || orbital == null)
            {
                _pinchZoomActive = false;
                return;
            }

            if (_touchCount == 2)
            {
                Touch t0 = Input.GetTouch(0);
                Touch t1 = Input.GetTouch(1);
                float dist = Vector2.Distance(t0.position, t1.position);
                if (!_pinchZoomActive)
                {
                    _pinchZoomActive = true;
                    _lastPinchDistance = dist;
                }
                else
                {
                    float delta = dist - _lastPinchDistance;
                    _lastPinchDistance = dist;
                    // Pinch outward increases distance → larger scale
                    ApplyRadialZoomDelta(delta * zoomSensitivityPinch);
                }
            }
            else
            {
                _pinchZoomActive = false;
            }
        }

        private void MigrateLegacyDeadZone()
        {
            if (_migratedDeadZoneToNormalized)
            {
                return;
            }

            // Older values were serialized in pixels; convert once to normalized short-side ratio.
            if (dragDeadZone > 0.05f)
            {
                dragDeadZone /= 1080f;
            }

            dragDeadZone = Mathf.Max(0.0001f, dragDeadZone);

            _migratedDeadZoneToNormalized = true;
        }

        private void Update()
        {
            //todo: should not always update
            if (_cinemachineCamera.Follow == null && CECGameRun.Instance.GetHostPlayer() != null)
            {
                if(CECGameRun.Instance.GetHostPlayer().PointCam != null)
                {
                    _cinemachineCamera.Follow = CECGameRun.Instance.GetHostPlayer().PointCam;
                    _cinemachineCamera.ForceCameraPosition(CECGameRun.Instance.GetHostPlayer().PointCam.position, Quaternion.identity);
                    ResetFollowCameraAxes();
                }
                else
                {
                    _cinemachineCamera.Follow = CECGameRun.Instance.GetHostPlayer().transform;
                    _cinemachineCamera.ForceCameraPosition(CECGameRun.Instance.GetHostPlayer().ObjectPosition, Quaternion.identity);
                    ResetFollowCameraAxes();
                }
            }

#if UNITY_EDITOR || UNITY_STANDALONE || UNITY_WEBGL
            if (CanApplyZoom && orbital != null)
            {
                float scroll = Input.mouseScrollDelta.y;
                if (Mathf.Abs(scroll) > Mathf.Epsilon)
                {
                    ApplyRadialZoomDelta(scroll * zoomSensitivityScroll);
                }
            }
#endif
            UpdatePinchZoom();
        }
        public void UpdateFollowObject(Transform followObject)
        {
            _cinemachineCamera.Follow = followObject;
            _cinemachineCamera.ForceCameraPosition(followObject.position, Quaternion.identity);
            ResetFollowCameraAxes();
        }
    }
}