using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.InputSystem.OnScreen;
using UnityEngine.Serialization;

namespace Superlazy.UI
{
    public class SLScreenStick : OnScreenControl, IPointerDownHandler, IPointerUpHandler, IDragHandler
    {
        public void OnPointerDown(PointerEventData eventData)
        {
            if (eventData == null)
                throw new System.ArgumentNullException(nameof(eventData));

            RectTransformUtility.ScreenPointToLocalPointInRectangle(transform.parent.GetComponentInParent<RectTransform>(), eventData.position, eventData.pressEventCamera, out pointerDownPos);
            padImagePos = rangeImage.position;
            rangeImage.position = eventData.position;
        }

        public void OnDrag(PointerEventData eventData)
        {
            if (eventData == null)
                throw new System.ArgumentNullException(nameof(eventData));

            RectTransformUtility.ScreenPointToLocalPointInRectangle(transform.parent.GetComponentInParent<RectTransform>(), eventData.position, eventData.pressEventCamera, out var position);
            var delta = position - pointerDownPos;

            delta = Vector2.ClampMagnitude(delta, MovementRange);
            padImage.anchoredPosition = startPos + (Vector3)delta;

            var newPos = new Vector2(delta.x / MovementRange, delta.y / MovementRange);
            SendValueToControl(newPos);
        }

        public void OnPointerUp(PointerEventData eventData)
        {
            SendValueToControl(Vector2.zero);
            padImage.anchoredPosition = startPos;
            rangeImage.position = padImagePos;
        }

        private void Start()
        {
            startPos = padImage.anchoredPosition;
        }

        public float MovementRange
        {
            get => movementRange;
            set => movementRange = value;
        }

        [FormerlySerializedAs("movementRange")]
        [SerializeField]
        private float movementRange = 50;

        [FormerlySerializedAs("PadImage")]
        [SerializeField]
        private readonly RectTransform padImage;

        [FormerlySerializedAs("RangeImage")]
        [SerializeField]
        private readonly Transform rangeImage;

        [FormerlySerializedAs("ControlPath")]
        [SerializeField]
        private new string controlPath;

        private Vector3 startPos;
        private Vector3 padImagePos;
        private Vector2 pointerDownPos;

        protected override string controlPathInternal
        {
            get => controlPath;
            set => controlPath = value;
        }
    }
}