#include <RtcDS1307.h>
#include <ThreeWire.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Arduino.h>
enum Mode
{
  CLOCK,
  ALARM,
  SET_DATE,
  SET_TIME
};
Mode mode = CLOCK;
byte AlarmHour = 7;
byte AlarmMin = 0;
byte AlarmDay = 1;
byte AlarmMon = 1;
bool AlarmArmed = false;
bool IsRinging = false;
unsigned long previousMillis = 0;
const unsigned long debouncedelay = 50;
const long interval = 500;
int ModeCount = 0;
int Previous_AlarmHour = 0;
int Previous_AlarmMin = 0;
int Previous_AlarmDay = 0;
int Previous_AlarmMon = 0;
#define BTN_MODE 2
#define BTN_HOUR 3
#define BTN_MIN 4
#define RTC_CLK 6
#define RTC_DAT 7
#define RTC_RST 8
#define BUZZER 9
int LastState_Mode = 1;
int LastState_Hour = 1;
int LastState_Min = 1;
int ButtonState_Mode = 1;
int ButtonState_Hour = 1;
int ButtonState_Min = 1;
unsigned long LastDebounce_Mode = 1;
unsigned long LastDebounce_Hour = 1;
unsigned long LastDebounce_Min = 1;
LiquidCrystal_I2C lcd(0x27, 16, 2);
RtcDS1307<TwoWire> Rtc(Wire);

void SaveAlarm()
{
  Rtc.SetMemory(1, 165);
  Rtc.SetMemory(2, AlarmMin);
  Rtc.SetMemory(3, AlarmHour);
  Rtc.SetMemory(4, AlarmDay);
  Rtc.SetMemory(5, AlarmMon);
  Rtc.SetMemory(6, AlarmArmed);
}

void LoadAlarm()
{
  if (Rtc.GetMemory(1) == 165)
  {
    AlarmHour = Rtc.GetMemory(3);
    AlarmMin = Rtc.GetMemory(2);
    AlarmDay = Rtc.GetMemory(4);
    AlarmMon = Rtc.GetMemory(5);
    AlarmArmed = Rtc.GetMemory(6);
  }
}

void setup()
{
  pinMode(BTN_MODE, INPUT_PULLUP);
  pinMode(BTN_HOUR, INPUT_PULLUP);
  pinMode(BTN_MIN, INPUT_PULLUP);
  pinMode(BUZZER, OUTPUT);
  lcd.init();
  lcd.backlight();
  Serial.begin(9600);
  Rtc.Begin();
  LoadAlarm();
  Rtc.SetIsRunning(true);
  RtcDateTime currentTime = RtcDateTime(__DATE__, __TIME__);
  if (!Rtc.IsDateTimeValid() || Rtc.GetDateTime() < currentTime)
  {
    Rtc.SetDateTime(currentTime);
  }
  Serial.println("RTC Successfully Booted!");
  Serial.println("------------------------");
}

void loop()
{
  RtcDateTime now = Rtc.GetDateTime();
  if (!now.IsValid())
  {
    Serial.println("RTC Wire Error! Check wires on pins A4,A5");
    delay(1000);
    return;
  }

  int Reading_Mode = digitalRead(BTN_MODE);
  if (Reading_Mode != LastState_Mode)
  {
    LastDebounce_Mode = millis();
  }
  if ((millis() - LastDebounce_Mode) > debouncedelay)
  {
    if (Reading_Mode != ButtonState_Mode)
    {
      ButtonState_Mode = Reading_Mode;
      if (ButtonState_Mode == 0)
      {
        if (IsRinging == true)
        {
          noTone(BUZZER);
          IsRinging = false;
        }
        else
        {
          ModeCount++;
          if (ModeCount > 3)
          {
            ModeCount = 0;
            if (Previous_AlarmDay != AlarmDay || Previous_AlarmHour != AlarmHour || Previous_AlarmMin != AlarmMin || Previous_AlarmMon != AlarmMon)
            {
              AlarmArmed = true;
            }
            SaveAlarm();
          }
          if (ModeCount == 0)
          {
            mode = CLOCK;
          }
          if (ModeCount == 1)
          {
            mode = ALARM;
          }
          if (ModeCount == 2)
          {
            mode = SET_DATE;
            if (!AlarmArmed)
            {
              AlarmDay = now.Day();
              AlarmMon = now.Month();
            }
            Previous_AlarmDay = AlarmDay;
            Previous_AlarmHour = AlarmHour;
            Previous_AlarmMin = AlarmMin;
            Previous_AlarmMon = AlarmMon;
          }
          if (ModeCount == 3)
          {
            mode = SET_TIME;
          }
          lcd.clear();
        }
      }
    }
  }
  LastState_Mode = Reading_Mode;

  int Reading_Hour = digitalRead(BTN_HOUR);
  if (Reading_Hour != LastState_Hour)
  {
    LastDebounce_Hour = millis();
  }
  if ((millis() - LastDebounce_Hour) > debouncedelay)
  {
    if (Reading_Hour != ButtonState_Hour)
    {
      ButtonState_Hour = Reading_Hour;
      if (ButtonState_Hour == 0)
      {
        if (IsRinging == true)
        {
          noTone(BUZZER);
          IsRinging = false;
        }
        else
        {

          if (mode == ALARM)
          {
            AlarmArmed = true;
            SaveAlarm();
          }
          if (mode == SET_DATE)
          {
            AlarmMon++;
          }
          if (AlarmMon > 12)
          {
            AlarmMon = 1;
          }
          if (mode == SET_TIME)
          {
            AlarmHour++;
          }
          if (AlarmHour > 23)
          {
            AlarmHour = 0;
          }
        }
      }
    }
  }
  LastState_Hour = Reading_Hour;

  int Reading_Min = digitalRead(BTN_MIN);
  if (Reading_Min != LastState_Min)
  {
    LastDebounce_Min = millis();
  }
  if ((millis() - LastDebounce_Min) > debouncedelay)
  {
    if (Reading_Min != ButtonState_Min)
    {
      ButtonState_Min = Reading_Min;
      if (ButtonState_Min == 0)
      {
        if (IsRinging == true)
        {
          noTone(BUZZER);
          IsRinging = false;
        }
        else
        {

          if (mode == ALARM)
          {
            AlarmArmed = false;
            SaveAlarm();
          }
          if (mode == SET_DATE)
          {
            AlarmDay++;
          }
          if (AlarmDay > 31)
          {
            AlarmDay = 1;
          }
          if (mode == SET_TIME)
          {
            AlarmMin++;
          }
          if (AlarmMin > 59)
          {
            AlarmMin = 0;
          }
        }
      }
    }
  }
  LastState_Min = Reading_Min;

  if (mode == CLOCK)
  {
    unsigned long currentMillis = millis();
    if (currentMillis - previousMillis >= interval)
    {
      previousMillis = currentMillis;

      Serial.print("Date: ");
      if (now.Day() < 10)
        Serial.print("0");
      Serial.print(now.Day());
      Serial.print("/");
      if (now.Month() < 10)
        Serial.print("0");
      Serial.print(now.Month());
      Serial.print("/");
      Serial.print(now.Year());
      Serial.print("   |   ");
      Serial.print("Time: ");
      if (now.Hour() < 10)
        Serial.print("0");
      Serial.print(now.Hour());
      Serial.print(":");
      if (now.Minute() < 10)
        Serial.print("0");
      Serial.print(now.Minute());
      Serial.print(":");
      if (now.Second() < 10)
        Serial.print("0");
      Serial.println(now.Second());

      lcd.setCursor(0, 0);
      lcd.print("Date: ");
      if (now.Day() < 10)
        lcd.print("0");
      lcd.print(now.Day());
      lcd.print("/");
      if (now.Month() < 10)
        lcd.print("0");
      lcd.print(now.Month());
      lcd.print("/");
      lcd.print(now.Year());
      lcd.setCursor(0, 1);
      lcd.print("Time: ");
      if (now.Hour() < 10)
        lcd.print("0");
      lcd.print(now.Hour());
      lcd.print(":");
      if (now.Minute() < 10)
        lcd.print("0");
      lcd.print(now.Minute());
      lcd.print(":");
      if (now.Second() < 10)
        lcd.print("0");
      lcd.print(now.Second());
    }
  }
  if (mode == ALARM)
  {
    unsigned long currentMillis = millis();
    if (currentMillis - previousMillis >= interval)
    {
      previousMillis = currentMillis;
      lcd.setCursor(0, 0);
      lcd.print("Alarm ");
      if (AlarmDay < 10)
      {
        lcd.print("0");
      }
      lcd.print(AlarmDay);
      lcd.print("/");
      if (AlarmMon < 10)
      {
        lcd.print("0");
      }
      lcd.print(AlarmMon);
      lcd.setCursor(0, 1);
      lcd.print("Time ");
      if (AlarmHour < 10)
      {
        lcd.print("0");
      }
      lcd.print(AlarmHour);
      lcd.print(":");
      if (AlarmMin < 10)
      {
        lcd.print("0");
      }
      lcd.print(AlarmMin);
      if (AlarmArmed == false)
      {
        lcd.print(" OFF");
      }
      else
      {
        lcd.print(" ON ");
      }
    }
  }
  if (mode == SET_DATE)
  {
    unsigned long currentMillis = millis();
    if (currentMillis - previousMillis >= interval)
    {
      previousMillis = currentMillis;
      lcd.setCursor(0, 0);
      lcd.print("Month: ");
      if (AlarmMon < 10)
      {
        lcd.print("0");
      }
      lcd.print(AlarmMon);
      lcd.setCursor(0, 1);
      lcd.print("Day:   ");
      if (AlarmDay < 10)
      {
        lcd.print("0");
      }
      lcd.print(AlarmDay);
    }
  }
  if (mode == SET_TIME)
  {
    unsigned long currentMillis = millis();
    if (currentMillis - previousMillis >= interval)
    {
      previousMillis = currentMillis;
      lcd.setCursor(0, 0);
      lcd.print("Hour:   ");
      if (AlarmHour < 10)
      {
        lcd.print("0");
      }
      lcd.print(AlarmHour);
      lcd.setCursor(0, 1);
      lcd.print("Minute: ");
      if (AlarmMin < 10)
      {
        lcd.print("0");
      }
      lcd.print(AlarmMin);
    }
  }
  if (now.Month() == AlarmMon && now.Day() == AlarmDay && now.Hour() == AlarmHour && now.Minute() == AlarmMin && AlarmArmed == true)
  {
    AlarmArmed = false;
    tone(BUZZER, 300);
    IsRinging = true;
    SaveAlarm();
  }
}