using UnityEngine;
using UnityEngine.Events;
using UnityEngine.EventSystems;
using UnityEngine.UI;

namespace SepCore.UI
{
    public class CommonButton : Button
    {
        [SerializeField] private Image _background = null;
        
        [SerializeField] private UnityEvent _onPointerEnterAction = new();

        [SerializeField] private UnityEvent _onPointerExitAction = new();

        public override void OnPointerEnter(PointerEventData eventData)
        {
            base.OnPointerEnter(eventData);
            if (eventData.button != PointerEventData.InputButton.Left || !IsActive() || !IsInteractable())
            {
                return;
            }

            EnterHoverState();
        }

        public override void OnPointerExit(PointerEventData eventData)
        {
            base.OnPointerExit(eventData);
            if (eventData.button != PointerEventData.InputButton.Left)
            {
                return;
            }

            ExitHoverState();
        }

        public override void OnSelect(BaseEventData eventData)
        {
            base.OnSelect(eventData);
            if (!IsActive() || !IsInteractable())
            {
                return;
            }

            EnterHoverState();
        }

        public override void OnDeselect(BaseEventData eventData)
        {
            base.OnDeselect(eventData);
            ExitHoverState();
        }

        protected override void DoStateTransition(SelectionState state, bool instant)
        {
            base.DoStateTransition(state, instant);
            if (transition == Transition.SpriteSwap)
            {
                _background.canvasRenderer.SetColor(
                    state == SelectionState.Highlighted || state == SelectionState.Selected
                        ? new Color(1f, 0.96f, 0.8f, 1f)
                        : Color.white);
            }
        }

        private void EnterHoverState()
        {
            if (EventSystem.current.currentSelectedGameObject != gameObject)
            {
                EventSystem.current.SetSelectedGameObject(this.gameObject);
            }

            _onPointerEnterAction.Invoke();
        }

        private void ExitHoverState()
        {
            _onPointerExitAction.Invoke();
        }

        public void RegisterPointerEnterAction(UnityAction action)
        {
            _onPointerEnterAction.AddListener(action);
        }

        public void RegisterPointerExitAction(UnityAction action)
        {
            _onPointerExitAction.AddListener(action);
        }

        public void UnregisterPointerEnterAction(UnityAction action)
        {
            _onPointerEnterAction.RemoveListener(action);
        }

        public void UnregisterPointerExitAction(UnityAction action)
        {
            _onPointerExitAction.RemoveListener(action);
        }
    }
}