using Cysharp.Threading.Tasks;
using DG.Tweening;
using System;
using System.Collections.Generic;
using TMPro;
using UnityEngine;
using UVC.Log;
using UVC.Util;

namespace UVC.UI.Modal.DatePicker
{
    public class DatePicker : MonoBehaviour
    {
        private static string PrefabPath = "Prefabs/UI/Modal/DatePicker/DatePicker";
        private const string blockerPrefabPath = "Prefabs/UI/Modal/ModalBlocker"; //menu blocker prefab path
        private static DatePicker instance;
        private static Action<DateTime> _onDateSelectedCallback;

        private Canvas parentCanvas;

        private static GameObject? blockerPrefabObj;
        private static GameObject currentBlockerInstance;

        [Header("Calendar")]
        [SerializeField]
        public GameObject _calendarPanel;
        [SerializeField]
        public TextMeshProUGUI _yearNumText;
        [SerializeField]
        public TextMeshProUGUI _monthNumText;
        [SerializeField]
        public GameObject _item;


        [Header("Colors")]
        [SerializeField]
        public Color textColor = ColorUtil.FromHex("808080");
        [SerializeField]
        public Color selectColor = ColorUtil.FromHex("F5A623");
        [SerializeField]
        public Color todayColor = Color.white;
        [SerializeField]
        public Color saturdayColor = ColorUtil.FromHex("4A90E2");
        [SerializeField]
        public Color sundayColor = ColorUtil.FromHex("FF5E5E");

        private List<GameObject> _dateItems = new List<GameObject>();
        private const int _totalDateNum = 42;

        private DateTime _initTime;
        private DateTime _dateTime;


        public static async UniTask Show(DateTime initialDate, Action<DateTime> onDateSelected)
        {
            bool hasInstance = true;
            if (instance == null)
            {
                hasInstance = false;
                var prefab = await Resources.LoadAsync<DatePicker>(PrefabPath) as DatePicker;
                instance = Instantiate(prefab);
                if (instance == null)
                {
                    Debug.LogError("No DatePicker prefab active on 'Start' in scene");
                    return;
                }
                Canvas[] canvases = FindObjectsByType<Canvas>(FindObjectsSortMode.None);
                //sortingOrder로 정렬 내림차순 - sortingOrder가 높은 캔버스가 먼저 오도록
                Array.Sort(canvases, (x, y) => y.sortingOrder.CompareTo(x.sortingOrder));
                foreach (Canvas c in canvases)
                {
                    if (c.renderMode != RenderMode.WorldSpace)
                    {
                        instance.transform.SetParent(c.transform, false);
                        instance.parentCanvas = c;
                        break;
                    }
                }
            }


            instance.gameObject.SetActive(true);
            instance._initTime = initialDate;
            instance._dateTime = initialDate;

            //화면 센터에 위치 시키기
            RectTransform rectTransform = instance.GetComponent<RectTransform>();
            rectTransform.anchoredPosition = new Vector2((Screen.width - rectTransform.sizeDelta.x) / 2, -(Screen.height - rectTransform.sizeDelta.y) / 2);
            _onDateSelectedCallback = onDateSelected;

            if (hasInstance) instance.CreateCalendar();

            ShowBlock();
        }

        public static void Hide()
        {
            if (instance != null) instance.gameObject.SetActive(false);
            _onDateSelectedCallback = null; // 콜백 참조 정리
            HideBlock();
        }

        private static async void ShowBlock()
        {
            if (blockerPrefabObj == null)
            {
                blockerPrefabObj = await Resources.LoadAsync<GameObject>(blockerPrefabPath) as GameObject;
            }
            if (blockerPrefabObj != null)
            {
                // 화면에서 가장 큰 그림판(Canvas)을 찾아서 그 위에 방패를 놓을 거예요.
                Canvas mainCanvasForBlocker = instance.parentCanvas;
                if (mainCanvasForBlocker != null)
                {
                    // 방패를 복제해서(Instantiate) 그림판 위에 놓고, 가장 위로 오도록 순서를 조정해요.
                    currentBlockerInstance = UnityEngine.Object.Instantiate(blockerPrefabObj, mainCanvasForBlocker.transform);
                    int siblingIndex = instance.transform.GetSiblingIndex();
                    currentBlockerInstance.transform.SetSiblingIndex(Math.Max(0, siblingIndex - 1));

                    // 방패가 부드럽게 나타나도록 CanvasGroup 컴포넌트를 사용해요. 없으면 새로 추가!
                    CanvasGroup blockerCanvasGroup = currentBlockerInstance.GetComponent<CanvasGroup>();
                    if (blockerCanvasGroup == null) blockerCanvasGroup = currentBlockerInstance.AddComponent<CanvasGroup>();
                    blockerCanvasGroup.alpha = 0f;// 처음엔 완전히 투명하게
                    blockerCanvasGroup.DOFade(0.7f, 0.3f);// 0.3초 동안 서서히 나타나게 (투명도 70%)
                }
                else ULog.Error("[Modal] UIBlocker를 표시할 Canvas를 찾을 수 없습니다."); // 그림판을 못 찾으면 에러!
            }
            else ULog.Warning($"[Modal] UIBlocker 프리팹을 다음 경로에서 찾을 수 없습니다: {blockerPrefabPath}");
        }

        private static void HideBlock()
        {
            if (currentBlockerInstance != null)
            {
                var blockerCG = currentBlockerInstance.GetComponent<CanvasGroup>();
                if (blockerCG != null)
                {
                    blockerCG.DOFade(0f, 0.3f).OnComplete(() =>
                    {
                        UnityEngine.Object.Destroy(currentBlockerInstance); // 완전히 제거
                    }); // 부드럽게 사라지게
                }
            }
        }

        void Start()
        {

            Vector3 startPos = _item.transform.localPosition;
            _dateItems.Clear();
            _dateItems.Add(_item);

            for (int i = 1; i < _totalDateNum; i++)
            {
                GameObject item = GameObject.Instantiate(_item) as GameObject;
                item.name = "Item" + (i + 1).ToString();
                item.transform.SetParent(_item.transform.parent);
                item.transform.localScale = Vector3.one;
                item.transform.localRotation = Quaternion.identity;
                item.transform.localPosition = new Vector3((i % 7) * 36 + startPos.x, startPos.y - (i / 7) * 30, startPos.z);

                _dateItems.Add(item);
            }

            //_dateTime = DateTime.Now;

            CreateCalendar();
        }

        void CreateCalendar()
        {

            DateTime firstDay = _dateTime.AddDays(-(_dateTime.Day - 1));
            int index = GetDays(firstDay.DayOfWeek);

            int date = 0;
            for (int i = 0; i < _totalDateNum; i++)
            {
                TextMeshProUGUI label = _dateItems[i].GetComponentInChildren<TextMeshProUGUI>();
                _dateItems[i].SetActive(false);

                DateTime day = firstDay.AddDays(date);

                Color txtColor = textColor;
                //토요일 색 변경
                if (day.DayOfWeek == DayOfWeek.Saturday) //토요일
                {
                    txtColor = saturdayColor;
                }
                else if (day.DayOfWeek == DayOfWeek.Sunday) //일요일
                {
                    txtColor = sundayColor;
                }

                //오늘 날짜인지 확인해서 text 색 변경
                if (day.Date == DateTime.Now.Date)
                {
                    txtColor = todayColor;
                }


                if (day.Date == _initTime.Date)
                {
                    //_initTime날짜와 같은 날짜면 색 변경
                    txtColor = selectColor;
                }

                label.color = txtColor;

                if (i >= index)
                {
                    DateTime thatDay = firstDay.AddDays(date);
                    if (thatDay.Month == firstDay.Month)
                    {
                        _dateItems[i].SetActive(true);

                        label.text = (date + 1).ToString();
                        date++;
                    }
                }
            }
            _yearNumText.text = _dateTime.Year.ToString();
            _monthNumText.text = _dateTime.Month.ToString("D2");
        }

        int GetDays(DayOfWeek day)
        {
            switch (day)
            {
                case DayOfWeek.Monday: return 1;
                case DayOfWeek.Tuesday: return 2;
                case DayOfWeek.Wednesday: return 3;
                case DayOfWeek.Thursday: return 4;
                case DayOfWeek.Friday: return 5;
                case DayOfWeek.Saturday: return 6;
                case DayOfWeek.Sunday: return 0;
            }

            return 0;
        }
        public void YearPrev()
        {
            _dateTime = _dateTime.AddYears(-1);
            CreateCalendar();
        }

        public void YearNext()
        {
            _dateTime = _dateTime.AddYears(1);
            CreateCalendar();
        }

        public void MonthPrev()
        {
            _dateTime = _dateTime.AddMonths(-1);
            CreateCalendar();
        }

        public void MonthNext()
        {
            _dateTime = _dateTime.AddMonths(1);
            CreateCalendar();
        }

        //Item 클릭했을 경우 Text에 표시.
        public void OnDateItemClick(string day)
        {
            string date = _yearNumText.text + "-" + _monthNumText.text + "-" + int.Parse(day).ToString("D2");
            _onDateSelectedCallback?.Invoke(DateTime.Parse(date));
            Hide();
        }

    }

}