#include <LiquidCrystal.h>

LiquidCrystal lcd(7, 6, 5, 4, 3, 2);

int setButtonPin = 8;
int leftButtonPin = 10;
int rightButtonPin = 11;
int upButtonPin = 12;
int downButtonPin = 13;
int alarmPin = 9;

bool alarmActive = false;
int clockHour = 0;
int clockMinute = 0;
int clockSecond = 0;
int alarmHour = 0;
int alarmMinute = 0;

unsigned long previousMillis = 0;
const long interval = 1000;

enum Mode { NORMAL, CLOCK_SET, ALARM_SET };
Mode currentMode = NORMAL;
int cursorPosition = 0;

unsigned long buttonPreviousMillis = 0;
const long buttonInterval = 200;

void setup() {
  lcd.begin(16, 2);
  lcd.print("Clock and Alarm");
  // No delay here
  lcd.clear();

  pinMode(setButtonPin, INPUT_PULLUP);
  pinMode(leftButtonPin, INPUT_PULLUP);
  pinMode(rightButtonPin, INPUT_PULLUP);
  pinMode(upButtonPin, INPUT_PULLUP);
  pinMode(downButtonPin, INPUT_PULLUP);
  pinMode(alarmPin, OUTPUT);
  digitalWrite(alarmPin, LOW);
}

void loop() {
  unsigned long currentMillis = millis();

  if (currentMillis - previousMillis >= interval) {
    previousMillis = currentMillis;
    incrementTime();
  }

  if (currentMode == NORMAL) {
    displayClockAndAlarm();
    handleButtons();
  } else if (currentMode == CLOCK_SET) {
    displayClockSetting();
    handleClockSetModeButtons();
  } else if (currentMode == ALARM_SET) {
    displayAlarmSetting();
    handleAlarmSetModeButtons();
  }
}

void incrementTime() {
  clockSecond++;
  if (clockSecond == 60) {
    clockSecond = 0;
    clockMinute++;
    if (clockMinute == 60) {
      clockMinute = 0;
      clockHour++;
      if (clockHour == 24) {
        clockHour = 0;
      }
    }
  }
}

void displayClockAndAlarm() {
  lcd.setCursor(0, 0);
  lcd.print("Clock: ");
  if (clockHour < 10) lcd.print("0");
  lcd.print(clockHour);
  lcd.print(":");
  if (clockMinute < 10) lcd.print("0");
  lcd.print(clockMinute);
  lcd.print(":");
  if (clockSecond < 10) lcd.print("0");
  lcd.print(clockSecond);

  lcd.setCursor(0, 1);
  lcd.print("Alarm: ");
  if (alarmHour < 10) lcd.print("0");
  lcd.print(alarmHour);
  lcd.print(":");
  if (alarmMinute < 10) lcd.print("0");
  lcd.print(alarmMinute);
  lcd.print(alarmActive ? " ON " : " OFF");
}

void handleButtons() {
  unsigned long buttonCurrentMillis = millis();

  if (buttonCurrentMillis - buttonPreviousMillis >= buttonInterval) {
    buttonPreviousMillis = buttonCurrentMillis;

    if (digitalRead(setButtonPin) == LOW) {
      currentMode = (currentMode == NORMAL) ? CLOCK_SET : NORMAL;
      lcd.clear();
    }
  }
}

void displayClockSetting() {
  lcd.setCursor(0, 0);
  lcd.print("Set Clock: ");
  if (clockHour < 10) lcd.print("0");
  lcd.print(clockHour);
  lcd.print(":");
  if (clockMinute < 10) lcd.print("0");
  lcd.print(clockMinute);
  lcd.print(":");
  if (clockSecond < 10) lcd.print("0");
  lcd.print(clockSecond);

  lcd.setCursor(0, 1);
  lcd.print("Set Alarm: ");
  if (alarmHour < 10) lcd.print("0");
  lcd.print(alarmHour);
  lcd.print(":");
  if (alarmMinute < 10) lcd.print("0");
  lcd.print(alarmMinute);
}

void handleClockSetModeButtons() {
  unsigned long buttonCurrentMillis = millis();

  if (buttonCurrentMillis - buttonPreviousMillis >= buttonInterval) {
    buttonPreviousMillis = buttonCurrentMillis;

    if (digitalRead(setButtonPin) == LOW) {
      currentMode = (currentMode == CLOCK_SET) ? NORMAL : ALARM_SET;
      lcd.clear();
    } else if (digitalRead(leftButtonPin) == LOW) {
      cursorPosition = (cursorPosition == 0) ? 1 : 0;
    } else if (digitalRead(rightButtonPin) == LOW) {
      cursorPosition = (cursorPosition == 0) ? 1 : 0;
    } else if (digitalRead(upButtonPin) == LOW) {
      if (cursorPosition == 0) {
        clockHour = (clockHour + 1) % 24;
      } else if (cursorPosition == 1) {
        clockMinute = (clockMinute + 1) % 60;
      } else {
        clockSecond = (clockSecond + 1) % 60;
      }
    } else if (digitalRead(downButtonPin) == LOW) {
      if (cursorPosition == 0) {
        clockHour = (clockHour - 1 + 24) % 24;
      } else if (cursorPosition == 1) {
        clockMinute = (clockMinute - 1 + 60) % 60;
      } else {
        clockSecond = (clockSecond - 1 + 60) % 60;
      }
    }
  }
}

void displayAlarmSetting() {
  lcd.setCursor(0, 0);
  lcd.print("Set Clock: ");
  if (clockHour < 10) lcd.print("0");
  lcd.print(clockHour);
  lcd.print(":");
  if (clockMinute < 10) lcd.print("0");
  lcd.print(clockMinute);
  lcd.print(":");
  if (clockSecond < 10) lcd.print("0");
  lcd.print(clockSecond);

  lcd.setCursor(0, 1);
  lcd.print("Set Alarm: ");
  if (alarmHour < 10) lcd.print("0");
  lcd.print(alarmHour);
  lcd.print(":");
  if (alarmMinute < 10) lcd.print("0");
  lcd.print(alarmMinute);
  lcd.print(alarmActive ? " ON " : " OFF");
}

void handleAlarmSetModeButtons() {
  unsigned long buttonCurrentMillis = millis();

  if (buttonCurrentMillis - buttonPreviousMillis >= buttonInterval) {
    buttonPreviousMillis = buttonCurrentMillis;

    if (digitalRead(setButtonPin) == LOW) {
      currentMode = (currentMode == ALARM_SET) ? NORMAL : CLOCK_SET;
      lcd.clear();
    } else if (digitalRead(leftButtonPin) == LOW) {
      cursorPosition = (cursorPosition == 0) ? 2 : 0;
    } else if (digitalRead(rightButtonPin) == LOW) {
      cursorPosition = (cursorPosition == 0) ? 2 : 0;
    } else if (digitalRead(upButtonPin) == LOW) {
      if (cursorPosition == 0) {
        alarmHour = (alarmHour + 1) % 24;
      } else if (cursorPosition == 2) {
        alarmMinute = (alarmMinute + 1) % 60;
      } else {
        alarmActive = !alarmActive;
      }
    } else if (digitalRead(downButtonPin) == LOW) {
      if (cursorPosition == 0) {
        alarmHour = (alarmHour - 1 + 24) % 24;
      } else if (cursorPosition == 2) {
        alarmMinute = (alarmMinute - 1 + 60) % 60;
      } else {
        alarmActive = !alarmActive;
      }
    }
  }
}