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

namespace Funique
{
    /// <summary>
    /// Toggle UI element with On/Off triggers and texture swap <br />
    /// ------------------------------------------------ <br />
    /// 勾選使用者介面元件, 包含 開/關 事件和圖片素材轉換
    /// </summary>
    [AddComponentMenu("Funique/Core/Toggle Button")]
    [RequireComponent(typeof(Button))]
    public class ToggleButton : MonoBehaviour
    {
        // 欄位
        #region Field
        [SerializeField] public UnityEvent OnClick;
        [SerializeField] public UnityEvent OffClick;
        [SerializeField] bool isoff;
        [SerializeField] Sprite OnTex;
        [SerializeField] Sprite OffTex;
        Button button;
        public bool IsOn => !isoff;
        #endregion


        // Unity 事件 
        #region Unity Event
        private void Start()
        {
            button = GetComponent<Button>();
            button.onClick.AddListener(ButtonOnClick);
            UpdateState();
        }
        #endregion


        // 配置
        #region Setter
        /// <summary>
        /// Override the on property <br />
        /// ------------------------------------------------ <br />
        /// 複寫 on 屬性
        /// </summary>
        /// <param name="b">value</param>
        /// <param name="call">Call triggers</param>
        public void SetState(bool b, bool call = false)
        {
            isoff = b;
            UpdateState();
            if (call) ButtonOnClick();
        }
        #endregion


        // 功能
        #region Utility
        void ButtonOnClick()
        {
            bool state = isoff;
            isoff = !state;
            UpdateState();
            if (state) OnClick.Invoke();
            else OffClick.Invoke();
        }
        void UpdateState()
        {
            button.image.sprite = isoff ? OnTex : OffTex;
        }
        #endregion
    }
}