using System;
using System.Collections;
using System.Collections.Generic;
using System.Globalization;
using TMPro;
using Unity.VisualScripting;
using UnityEngine;
using UnityEngine.UI;
using WI;

public class UI_Calendar : UIBase
{
    public List<UI_CalendarItem> calendarItemList = new List<UI_CalendarItem>();
    public GameObject prefab_calendarItem;
    public RectTransform Text_Sunday;
    public RectTransform Text_Monday;
    public RectTransform ItemRoot;
    public TextMeshProUGUI Text_Day;
    public Button Button_PrevMonth;
    public Button Button_NextMonth;
   
    private const int totalItemNum = 42;

    private DateTime originDateTime;
    private DateTime curDateTime;

    private TextMeshProUGUI targetText;
    public float startSpace;
    public float endSpace;

    public Action<TextMeshProUGUI> onSelectDate;

    public override void AfterAwake()
    {
        Button_PrevMonth.onClick.AddListener(OnClickPrevMonth);
        Button_NextMonth.onClick.AddListener(OnClickNextMonth);

        prefab_calendarItem = Resources.Load<GameObject>("Prefabs/UI/PRF_UI_CalendarItem");
        float sundayPosX = Text_Sunday.anchoredPosition.x;
        float mondayPosX = Text_Monday.anchoredPosition.x;
        float space = mondayPosX - sundayPosX;
        Vector2 prefabSize = prefab_calendarItem.GetComponent<RectTransform>().sizeDelta;
        Vector2 itemStartPos = new Vector2(Text_Sunday.anchoredPosition.x, Text_Sunday.anchoredPosition.y - startSpace);

        for (int i = 0; i < totalItemNum; i++)
        {
            UI_CalendarItem item = Instantiate(prefab_calendarItem.gameObject, ItemRoot).GetComponent<UI_CalendarItem>();
            item.onClickEvent += OnClickItem;
            item.GetComponent<RectTransform>().anchoredPosition = new Vector3((i % 7) * space + itemStartPos.x, itemStartPos.y - (i / 7) * endSpace);
            calendarItemList.Add(item);
        }
    }

    public void Open(TextMeshProUGUI target)
    {
        targetText = target;
        originDateTime = Convert.ToDateTime(targetText.text);
        curDateTime = Convert.ToDateTime(targetText.text);
        SetActive(true);
        SetCalendar();
    }

    public void Close()
    {
        SetActive(false);
    }
    void Update()
    {
        if (Input.GetMouseButtonDown(0))
        {
            if (RectTransformUtility.RectangleContainsScreenPoint(rectTransform, Input.mousePosition))
                return;

            Close();
        }
    }

    void SetCalendar()
    {
        DateTime firstDay = curDateTime.AddDays(-(curDateTime.Day - 1));
        int weekIndex = (int)firstDay.DayOfWeek;
        int curMonthDaysCount = DateTime.DaysInMonth(curDateTime.Year, curDateTime.Month);
        DateTime lastMonth = firstDay.AddDays(-1);
        int lastMonthDaysCount = DateTime.DaysInMonth(lastMonth.Year, lastMonth.Month);
        DateTime today = DateTime.Today;

        int date = 0;

        for (int i = 0; i < totalItemNum; i++)
        {
            if (i >= weekIndex)
            {
                DateTime day = firstDay.AddDays(date);
                if (day.Month == firstDay.Month) // ÇöÀç ´Þ
                {
                    calendarItemList[i].SetDate(day, Color.white);

                    if (originDateTime.Date == day.Date)
                    {
                        calendarItemList[i].ShowSelectUI();
                    }
                    else if(today == day.Date)
                    {
                        calendarItemList[i].ShowTodayUI();
                    }
                }
                else // ´ÙÀ½ ´Þ
                {
                    int nextMonthDay = date + 1 - curMonthDaysCount;
                    DateTime nextMonthDate = new DateTime(day.Year, day.Month, nextMonthDay);
                    calendarItemList[i].SetDate(nextMonthDate, Color.gray);

                    if (today == nextMonthDate)
                    {
                        calendarItemList[i].ShowTodayUI();
                    }
                }

                date++;
            }
            else // ÀÌÀü ´Þ
            {
                DateTime LastMonthDate = new DateTime(lastMonth.Year, lastMonth.Month, lastMonthDaysCount - (weekIndex - i - 1));
                calendarItemList[i].SetDate(LastMonthDate, Color.gray);

                if (today == LastMonthDate)
                {
                    calendarItemList[i].ShowTodayUI();
                }
            }
        }

        Text_Day.text = $"{curDateTime.ToString("MMMM", new CultureInfo("en-US"))} {curDateTime.Year}";
    }

    private void OnClickItem(DateTime date)
    {
        targetText.text = date.ToString("yyyy-MM-dd");
        onSelectDate?.Invoke(targetText);
        Close();
    }

    private void OnClickPrevMonth()
    {
        curDateTime = curDateTime.AddMonths(-1);
        SetCalendar();
    }

    private void OnClickNextMonth()
    {
        curDateTime = curDateTime.AddMonths(1);
        SetCalendar();
    }
}