#include <Arduino.h>
#include <Adafruit_GFX.h>
#include <Adafruit_ILI9341.h>
//#include <RTClib.h>
//#include "button.h"
#include <time.h>

#define TFT_CS 10
#define TFT_DC 7
#define TFT_RST -1


const char *days[] = {"Mo", "Tu", "We", "Th", "Fr", "Sa", "Su"};

Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC, TFT_RST);

//RTC_DS1307 rtc;

int getDaysInMonth(int year, int month)
{
  if (month == 2)
  {
    if ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0))
    {
      return 29; // February in a leap year
    }
    else
    {
      return 28; // February in a non-leap year
    }
  }
  else if (month == 4 || month == 6 || month == 9 || month == 11)
  {
    return 30; // April, June, September, and November
  }
  else
  {
    return 31; // All other months
  }
}

void drawCalendar(int currentDay, int month, int year) {
  tft.setTextColor(ILI9341_WHITE);
  tft.setTextSize(1);

  char text[30];
  int text_w, pos_x, pos_y;
  int16_t x1, y1;
  uint16_t w, h;



  // Calculate the day of the week for the first day of the month
  struct tm tm = {0};
  tm.tm_mday = 1;
  tm.tm_mon = month - 1; // Months are 0-based in tm structure
  tm.tm_year = year - 1900; // Years are years since 1900 in tm structure
  mktime(&tm); // Update the tm structure with the correct values
  //int firstDayOfWeek = tm.tm_wday; // Get the day of the week
  int firstDayOfWeek = (tm.tm_wday == 1) ? 7 : (tm.tm_wday - 1);
  int day = 1;
  String str_day = (String) day;
  int days_of_month = getDaysInMonth(year, month);

  pos_x = 0;
  pos_y = 36;
  for (int i = 0; i < 7; i++)
  {
    pos_x = 104 + i * (tft.width() - 108) / 7;
    
    tft.getTextBounds(days[i], 0, 0, &x1, &y1, &w, &h);
    tft.setCursor(pos_x + ((tft.width() - 100) / 7 - w) / 2, pos_y);
    tft.print(days[i]);
    //  tft.setCursor(pos_x+((tft.width()-100)/7-w)/2, pos_y);
  }


  tft.drawLine(102, 48, 260, 48, ILI9341_BLUE);

  //pos_y = 55;
  pos_y = 55;

  // Skip the days before the first day of the month
  /*
    for (int i=0; i<firstDayOfWeek; i++)
    {
    pos_x = 104 + i*(tft.width()-108)/7;
    tft.setCursor(pos_x, pos_y);
    tft.print(" "); // Print two spaces for empty days
    }
  */
  day = (firstDayOfWeek - 1) * -1;
  int startDay = firstDayOfWeek;
  Serial.print("Start Day:"); Serial.println(startDay);

  while (day <= days_of_month)
  {
    for (int i = 0; i < 7; i++)
    {
      //      pos_x = 104 + ((i + firstDayOfWeek - 1) % 7) * (tft.width()-108)/7;
      pos_x = 104 + (i % 7) * (tft.width() - 108) / 7;

      if ((day >= 1) && (day <= days_of_month))
      {
        tft.getTextBounds(str_day, 0, 0, &x1, &y1, &w, &h);
        pos_x += (tft.width() - 108) / 7 / 2 - w / 2;
        tft.setCursor(pos_x, pos_y);

        // highlight today with filled red circle
        if (day == currentDay)
        {
          int cur_x = tft.getCursorX();
          int cur_y = tft.getCursorY();

          tft.setTextColor(ILI9341_RED);

          tft.fillCircle(cur_x + 3, cur_y + 3, 7, ILI9341_RED);
          tft.setTextColor(ILI9341_WHITE);
          if (day > 0)
            tft.print(day);
        }
        else
        {
          if (day > 0)
            tft.print(day);
        }
      }
      day++;
    }
    pos_y += 16;
    startDay = 0;
  }
}


void setup() {
  Serial.begin(115200);
  tft.begin();
  // rtc.begin();

  char buf[4];
  struct tm tm = {0};
  for (int month=0; month<12; month++) {
    tm = {0};
    tm.tm_mday = 1;
    tm.tm_mon = month;
    tm.tm_year = 2025 - 1900;

    mktime(&tm);
    strftime(buf, sizeof(buf), "%U", &tm); Serial.print("week:  "); Serial.print(buf);
    strftime(buf, sizeof(buf), "%b", &tm); Serial.print(", month: "); Serial.println(buf);
  }
  while (1);

  drawCalendar(4, 1, 2026);

}

void loop() {
}