using System;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.EventSystems;

namespace JCUnityLib.UI
{
    [ExecuteAlways]
    [RequireComponent(typeof(RectBorder))]
    public class TwoPoleSwitch : MonoBehaviour, IPointerClickHandler
    {
        public RectTransform rectTransform { get => transform as RectTransform; }
        public RectTransform point;
        [SerializeField] bool _isSwitchOn = true;
        public bool isSwitchOn
        {
            get => _isSwitchOn;
            set 
            {
                _isSwitchOn = value;
                UpdateStatus();
            }
        }
        public Color colorSwitchOn = new Color(99/255f, 221/255f, 251/255f, 1);
        public Color colorSwitchOff = new Color(142/255f, 142/255f, 142/255f, 1);
        public Func<bool, bool> onClick;
        Image _image;
        void Start()
        {
            UpdateStatus();
        }
        void Update()
        {
            #if UNITY_EDITOR
            UpdateStatus();
            #endif
        }
        void UpdateStatus()
        {
            if (!_image) _image = GetComponent<Image>();
            _image.color = isSwitchOn ? colorSwitchOn : colorSwitchOff;
            var borderWidth = (rectTransform.rect.height - point.rect.height) / 2;
            point.localPosition = (isSwitchOn ? Vector2.right : Vector2.left) * (rectTransform.rect.width / 2 - borderWidth - point.rect.width / 2);
        }
        public void OnPointerClick(PointerEventData eventData)
        {
            bool nextStatus = !isSwitchOn;
            bool canChange = true;
            if (onClick != null) canChange = onClick.Invoke(nextStatus);
            if (canChange) isSwitchOn = nextStatus;
        }
    }
}