#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <RTClib.h>

RTC_DS1307 rtc;
Adafruit_SSD1306 display(128, 64, &Wire, -1);

int hour_button = 2;
int minute_button = 3;
int set_button = 4;
int exit_button = 5;
int show_alarms_button = 7;
int led1 = 6;

const int numTimers = 3;
int alarmHour[numTimers] = {0, 0, 0};
int alarmMinute[numTimers] = {0, 0, 0};
int activate[numTimers] = {0, 0, 0};
int setAlarm[numTimers] = {0, 0, 0};
bool setTimeMode = false;
int activeTimer = 0;
bool alarmTriggered = false;
int triggeredAlarmIndex = -1;

unsigned long setButtonPressStartTime = 0;
unsigned long hourButtonPressStartTime = 0;
bool hourButtonLongPressed = false;

enum DaysOfWeek { Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday };

void setDefaultTime();
String getDayOfWeek(int day);
void displayCurrentTime(DateTime currentTime);
void displaySetTime(int timerIndex, int hour, int minute);
void displayActiveAlarms();
void stopAlarm();
void cycleAlarmSettings();
void incrementAlarmAndDisplay();
void showButtonInterrupt();

void setup() {
  pinMode(hour_button, INPUT_PULLUP);
  pinMode(minute_button, INPUT_PULLUP);
  pinMode(set_button, INPUT_PULLUP);
  pinMode(exit_button, INPUT_PULLUP);
  pinMode(show_alarms_button, INPUT_PULLUP);
  pinMode(led1, OUTPUT);

  Serial.begin(9600);

  if (!rtc.begin()) {
    Serial.println(F("Couldn't find RTC"));
    while (1);
  }

  if (!rtc.isrunning()) {
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  }

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for (;;) {
    }
  }

  display.display();
  delay(50);

  display.clearDisplay();
  display.display();

  attachInterrupt(digitalPinToInterrupt(show_alarms_button), showButtonInterrupt, FALLING);
}

void showButtonInterrupt() {
  static unsigned long showButtonPressStartTime = 0;
  static bool showButtonLongPressed = false;

  if (digitalRead(show_alarms_button) == LOW) {
    if (showButtonPressStartTime == 0) {
      showButtonPressStartTime = millis();
    } else {
      unsigned long currentTime = millis();
      if (currentTime - showButtonPressStartTime >= 1000 && !showButtonLongPressed) {
        showButtonLongPressed = true;
        showButtonPressStartTime = 0;
        setDefaultTime();
      }
    }
  } else {
    showButtonPressStartTime = 0;
    showButtonLongPressed = false;
  }
}

String getDayOfWeek(int day) {
  switch (day) {
    case 1:
      return "Monday";
    case 2:
      return "Tuesday";
    case 3:
      return "Wednesday";
    case 4:
      return "Thursday";
    case 5:
      return "Friday";
    case 6:
      return "Saturday";
    case 7:
      return "Sunday";
    default:
      return "Invalid Day";
  }
}

void setDefaultTime() {
  int defaultHour = 12;
  int defaultMinute = 0;
  DaysOfWeek defaultDay = Monday;

  display.clearDisplay();
  display.setTextSize(1.5);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.println("Set Default Time");

  display.print("Hour:");
  display.setCursor(100, 20);
  display.print(defaultHour);
  display.setCursor(0, 35);
  display.print("Minute:");
  display.setCursor(100, 35);
  display.print(defaultMinute);
  display.setCursor(0, 50);
  display.print("Day:");
  display.setCursor(100, 50);
  display.print(getDayOfWeek(defaultDay));

  display.display();

  while (1) {
    int hour_button_state = digitalRead(hour_button);
    int minute_button_state = digitalRead(minute_button);
    int exit_button_state = digitalRead(exit_button);
    int set_button_state = digitalRead(set_button);

    if (hour_button_state == LOW) {
      defaultHour++;
      if (defaultHour > 23) {
        defaultHour = 0;
      }
      display.setCursor(100, 20);
      display.print("   ");
      display.setCursor(100, 20);
      display.print(defaultHour);
      delay(50);
    }

    if (minute_button_state == LOW) {
      defaultMinute++;
      if (defaultMinute > 59) {
        defaultMinute = 0;
      }
      display.setCursor(100, 35);
      display.print("   ");
      display.setCursor(100, 35);
      display.print(defaultMinute);
      delay(50);
    }

    if (exit_button_state == LOW) {
      setTimeMode = false;
      display.clearDisplay();
      displayCurrentTime(rtc.now());
      return;
    }

    if (set_button_state == LOW) {
      // Set the default time for both RTC and display
      rtc.adjust(DateTime(rtc.now().year(), rtc.now().month(), rtc.now().day(), defaultHour, defaultMinute, 0));
      display.clearDisplay();
      displayCurrentTime(rtc.now());
      return;
    }
  }
}

void displayCurrentTime(DateTime currentTime) {
  display.clearDisplay();

  display.setTextSize(2);
  display.setTextColor(SSD1306_WHITE);

  display.setCursor(0, 0);
  display.println(getDayOfWeek(currentTime.dayOfTheWeek()));
  display.print(currentTime.month());
  display.print("/");
  display.print(currentTime.day());
  display.print("/");
  display.println(currentTime.year());

  display.setCursor(0, 32);
  display.print(currentTime.hour());
  display.print(":");
  display.print(currentTime.minute());
  display.print(":");
  display.println(currentTime.second());

  display.display();
}

void displaySetTime(int timerIndex, int hour, int minute) {
  display.clearDisplay();
  display.setTextSize(1.5);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.print("Set Alarm ");
  display.print(timerIndex + 1);
  display.setCursor(0, 20);
  display.print("Hour:");
  display.setCursor(100, 20);
  display.print(hour);
  display.setCursor(0, 35);
  display.print("Minute:");
  display.setCursor(100, 35);
  display.print(minute);
  display.display();
}

void displayActiveAlarms() {
  display.clearDisplay();
  display.setTextSize(1.5);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.println("Active Alarms");

  for (int i = 0; i < numTimers; ++i) {
    display.print("Timer ");
    display.print(i + 1);
    display.print(": ");
    display.print(alarmHour[i]);
    display.print(":");
    display.print(alarmMinute[i]);
    display.println();
  }

  display.display();
}

void stopAlarm() {
  digitalWrite(led1, LOW);
  alarmTriggered = false;
  if (triggeredAlarmIndex != -1) {
    setAlarm[triggeredAlarmIndex] = 0;
    triggeredAlarmIndex = -1;
  }
}

void cycleAlarmSettings() {
  activeTimer = (activeTimer + 1) % numTimers;
  display.clearDisplay();
}

void incrementAlarmAndDisplay() {
  activeTimer = (activeTimer + 1) % numTimers;
  displaySetTime(activeTimer, alarmHour[activeTimer], alarmMinute[activeTimer]);
}

void loop() {
  int set_button_state = digitalRead(set_button);
  int exit_button_state = digitalRead(exit_button);
  int show_alarms_button_state = digitalRead(show_alarms_button);
  int hour_button_state = digitalRead(hour_button);

  if (activate[activeTimer] == 0) {
    DateTime now = rtc.now();
    displayCurrentTime(now);
    delay(50);

    for (int i = 0; i < numTimers; ++i) {
      if (setAlarm[i] == 1 && now.hour() == alarmHour[i] && now.minute() == alarmMinute[i]) {
        if (!alarmTriggered) {
          digitalWrite(led1, HIGH);
          alarmTriggered = true;
          triggeredAlarmIndex = i;
        }

        display.setTextSize(1.5);
        display.setTextColor(SSD1306_WHITE);
        display.setCursor(0, 48);
        display.println("Alarm Triggered!");
        display.display();

        if (exit_button_state == LOW) {
          stopAlarm();
          display.clearDisplay();
          displayCurrentTime(now);
          return;
        } else {
          delay(3000);
          stopAlarm();
          displayCurrentTime(now);
        }
      }
    }
  }

  if (set_button_state == LOW && activate[activeTimer] == 0) {
    setButtonPressStartTime = millis();
    activate[activeTimer] = 1;
    setTimeMode = !setTimeMode;
    display.clearDisplay();
  }

  if (setTimeMode) {
    if (set_button_state == HIGH) {
      unsigned long currentTime = millis();
      if (currentTime - setButtonPressStartTime >= 1000) {
        cycleAlarmSettings();
        setButtonPressStartTime = currentTime;
      }
    }

    static unsigned long showAlarmsButtonPressStartTime = 0;
    if (show_alarms_button_state == LOW) {
      if (showAlarmsButtonPressStartTime == 0) {
        showAlarmsButtonPressStartTime = millis();
      } else {
        unsigned long currentTime = millis();
        if (currentTime - showAlarmsButtonPressStartTime >= 1000) {
          showAlarmsButtonPressStartTime = 0;
          setDefaultTime();
        }
      }
    } else {
      showAlarmsButtonPressStartTime = 0;
    }

    if (hour_button_state == LOW) {
      if (millis() - hourButtonPressStartTime >= 1000 && !hourButtonLongPressed) {
        hourButtonLongPressed = true;
        hourButtonPressStartTime = 0;
        setDefaultTime();
      }
    } else {
      hourButtonPressStartTime = millis();
      hourButtonLongPressed = false;
    }

    if (show_alarms_button_state == LOW) {
      display.clearDisplay();
      incrementAlarmAndDisplay();
    }

    if (exit_button_state == LOW) {
      setTimeMode = false;
      activate[activeTimer] = 0;
      setAlarm[activeTimer] = 1;
      delay(50);
      cycleAlarmSettings();
    }
  }

  if (show_alarms_button_state == LOW) {
    if (setTimeMode) {
      display.clearDisplay();
      incrementAlarmAndDisplay();
    } else {
      if (alarmTriggered) {
        stopAlarm();
      }
      displayActiveAlarms();
      delay(3500);
      displayCurrentTime(rtc.now());
    }
  }

  while (activate[activeTimer] == 1) {
    if (setTimeMode) {
      displaySetTime(activeTimer, alarmHour[activeTimer], alarmMinute[activeTimer]);

      int hour_button_state = digitalRead(hour_button);
      if (hour_button_state == LOW) {
        alarmHour[activeTimer]++;
        if (alarmHour[activeTimer] > 23) {
          alarmHour[activeTimer] = 0;
        }
        delay(50);
      }

      int minute_button_state = digitalRead(minute_button);
      if (minute_button_state == LOW) {
        alarmMinute[activeTimer]++;
        if (alarmMinute[activeTimer] > 59) {
          alarmMinute[activeTimer] = 0;
        }
        delay(50);
      }

      int exit_button_state = digitalRead(exit_button);
      if (exit_button_state == LOW) {
        setTimeMode = false;
        activate[activeTimer] = 0;
        setAlarm[activeTimer] = 1;
        delay(50);
        cycleAlarmSettings();
      }
    } else {
      displayCurrentTime(rtc.now());
    }

    delay(20);
  }

  if (setAlarm[activeTimer] == 1) {
    DateTime now = rtc.now();
    displayCurrentTime(now);
    delay(50);
    display.clearDisplay();
    display.display();
    setAlarm[activeTimer] = 0;
  }
}