using System.Collections.Generic;
using System.Linq;
using AibisDream.Framework;
using AibisDream.Kit;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;

namespace AibisDream
{
    public class CursorManager : Singleton<CursorManager>
    {
        [SerializeField] private GameObject border;

        [Header("指针图片")] public Sprite defaultCursor;
        public Sprite nextTalk, talking, option, interactive, holding, disable;

        private Image _cursor;
        private GraphicRaycaster _raycaster;

        private CursorState _stateCache;

        #region 状态相关

        private Coroutine _switchCoroutine;
        private CursorState _curState = CursorState.Default;
        private bool _isTalking;
        private bool _isInGame;

        #endregion

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

        private void Start()
        {
            border.SetActive(true);
            InitRefs();
            InitCursor();
        }

        private void InitCursor()
        {
            Cursor.visible = false;
            _cursor.sprite = defaultCursor;
        }

        private void OnEnable()
        {
            RegisterEvent();
        }

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

            _unRegisters.Clear();
        }

        private void InitRefs()
        {
            _cursor = transform.Find("Cursor").GetComponent<Image>();
            _raycaster = UIManager.Instance.Canvas.GetComponent<GraphicRaycaster>();
        }

        private void RegisterEvent()
        {
            // 此处监听所有可能对鼠标状态产生影响的事件
            RegisterGameEvent();
        }

        private void RegisterGameEvent()
        {
            _unRegisters.Add(EnumEventSystem.Global.Register(GameLoopEnum.GameStart, OnGameStart));
            _unRegisters.Add(EnumEventSystem.Global.Register(GameLoopEnum.GameQuit, OnGameQuit));
            _unRegisters.Add(EnumEventSystem.Global.Register(GameLoopEnum.PauseGame, OnPauseGame));
            _unRegisters.Add(EnumEventSystem.Global.Register(GameLoopEnum.UnPauseGame, OnUnPauseGame));
        }

        private void OnGameStart()
        {
            _isInGame = true;
        }

        private void OnUnPauseGame()
        {
            _curState = _stateCache;
            _stateCache = CursorState.Default;

            _isInGame = true;
        }

        private void OnPauseGame()
        {
            _stateCache = _curState;
            _curState = CursorState.Default;

            _isInGame = false;
        }

        private void OnGameQuit()
        {
            _curState = CursorState.Default;
            _stateCache = CursorState.Default;

            _isInGame = false;
        }

        private bool IsOverSelected()
        {
            if (!EventSystem.current.IsPointerOverGameObject())
            {
                return false;
            }

            var eventData = new PointerEventData(EventSystem.current)
            {
                position = Input.mousePosition
            };

            var results = new List<RaycastResult>();
            _raycaster.Raycast(eventData, results);

            return results.Count > 0 && results.Any(result => result.gameObject.CompareTag("Selectable"));
        }

        private void LateUpdate()
        {
            // // 将虚拟指针与鼠标位置同步
            // RectTransformUtility.ScreenPointToLocalPointInRectangle(_cursorCanvas, Input.mousePosition,
            //     CameraKit.Instance.uiCamera, out var worldPos);

            _cursor.rectTransform.position = Input.mousePosition;

            // 在输入状态，要单独处理
        }
    }

    public enum CursorState
    {
        Default,
        Interactive
    }
}