using System.Collections.Generic;
using AibisDream.Framework;
using UnityEngine;
using UnityEngine.UI;

namespace AibisDream
{
    public class CursorManager : MonoBehaviour
    {
        [Header("指针图片")] public Sprite defaultCursor;
        public Sprite nextTalk, talking, option, interactive, holding, disable, eye;

        private Image _cursor;
        private RectTransform _cursorCanvas;

        // 卸载时注销事件
        private List<IUnRegister> _eventUnRegisters = new();

        public void Awake()
        {
            InitRefs();
            InitCursor();
        }

        private void InitCursor()
        {
            SwitchCursorImage(defaultCursor);
        }

        private void OnEnable()
        {
            RegisterEvent();
        }

        private void OnDisable()
        {
            // 注销所有事件
            foreach (var eventUnRegister in _eventUnRegisters)
            {
                eventUnRegister.UnRegister();
            }

            _eventUnRegisters.Clear();
        }

        private void InitRefs()
        {
            _cursor = transform.Find("Cursor").GetComponent<Image>();
            _cursorCanvas = GetComponent<RectTransform>();
        }

        private void RegisterEvent()
        {
            // 此处监听所有可能对鼠标状态产生影响的事件
            // 对话相关
            EnumEventSystem.Global.Register<DialogEventEnum, DialogLine>(DialogEventEnum.LineStart, OnDialogLineStart);
            EnumEventSystem.Global.Register(DialogEventEnum.OptionShow, () => SwitchCursorImage(option));
            
        }

        private void LateUpdate()
        {
            // 获取鼠标指针在UI Camera上的位置
            RectTransformUtility.ScreenPointToLocalPointInRectangle(_cursorCanvas, Input.mousePosition,
                CameraKit.Instance.uiCamera, out var worldPos);

            _cursor.rectTransform.localPosition = worldPos;
        }

        private void SwitchCursorImage(Sprite sprite)
        {
            _cursor.sprite = sprite;
        }

        private void OnDialogLineStart(DialogLine line)
        {
            // 对话指针
            if (!line.isOption) SwitchCursorImage(talking);
        }

        private void OnDialogLineEnd()
        {
            // 下一句指针
            SwitchCursorImage(nextTalk);
        }
    }
}