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

RTC_DS3231 rtc;

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1
#define SCREEN_ADDRESS 0x3C
#define BUTTON_PIN 3
#define UP_BUTTON_PIN 4
#define DOWN_BUTTON_PIN 5
#define LED_PIN 11
#define BUZZER_PIN 12  // Buzzer pin
#define SERVO_PIN 9     // Servo pin
#define LED_ON_TIME 1000

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
Servo servoMotor;

enum State {
  NORMAL,
  SETTING_ALARM_DATE,
  SETTING_ALARM_HOUR,
  SETTING_ALARM_MINUTE,
  SETTING_ALARM_CONFIRM,
  MELODY_PLAYBACK
};

State currentState = NORMAL;
DateTime alarmTime;
DateTime currentTime;
unsigned long alarmActivationTime = 0;
bool updateDisplay = true;  // Flag to control display updates

void setup() {
  Serial.begin(9600);

  pinMode(BUTTON_PIN, INPUT_PULLUP);
  pinMode(UP_BUTTON_PIN, INPUT_PULLUP);
  pinMode(DOWN_BUTTON_PIN, INPUT_PULLUP);
  pinMode(LED_PIN, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);

  servoMotor.attach(SERVO_PIN);

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

  if (rtc.lostPower()) {
    Serial.println("RTC lost power, setting the time...");
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  }

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

  display.display();
  delay(1000);
  display.clearDisplay();
}

void loop() {
  currentTime = rtc.now();
  handleButtons();

  switch (currentState) {
    case NORMAL:
      displayNormalView(currentTime);
      break;
    case SETTING_ALARM_DATE:
    case SETTING_ALARM_HOUR:
    case SETTING_ALARM_MINUTE:
    case SETTING_ALARM_CONFIRM:
      displaySettingAlarmView(alarmTime);
      break;
    case MELODY_PLAYBACK:
      ringAlarm();
      delay(900);
  }

  // Check if the alarm time has been reached
  if (checkAlarmTimeReached(currentTime, alarmTime)) {
    activateAlarm();  // Activate the alarm
  } else {
    deactivateAlarm();  // Deactivate the alarm
  }

  if (updateDisplay) {
    display.display();
    delay(500);
    display.clearDisplay();
  }
}

void handleButtons() {
  static unsigned long lastButtonPressTime = 0;
  static const unsigned long buttonDebounceDelay = 200;
  unsigned long currentMillis = millis();

  if (currentMillis - lastButtonPressTime >= buttonDebounceDelay) {
    if (digitalRead(BUTTON_PIN) == LOW) {
      handleEnterButtonPress();
    }

    if (currentState == SETTING_ALARM_DATE) {
      handleSettingAlarmDateButtons();
    } else if (currentState == SETTING_ALARM_HOUR || currentState == SETTING_ALARM_MINUTE) {
      handleSettingAlarmTimeButtons();
    }

    lastButtonPressTime = currentMillis;
  }
}

void handleEnterButtonPress() {
  switch (currentState) {
    case NORMAL:
      currentState = SETTING_ALARM_DATE;
      alarmTime = currentTime;
      break;
    case SETTING_ALARM_DATE:
      currentState = SETTING_ALARM_HOUR;
      break;
    case SETTING_ALARM_HOUR:
      currentState = SETTING_ALARM_MINUTE;
      break;
    case SETTING_ALARM_MINUTE:
      currentState = SETTING_ALARM_CONFIRM;
      break;
    case SETTING_ALARM_CONFIRM:
      currentState = NORMAL;
      // Save the alarm time or take any necessary action
      break;
  }
}

void handleSettingAlarmDateButtons() {
  if (digitalRead(UP_BUTTON_PIN) == LOW) {
    incrementDate(alarmTime, 1);
  }

  if (digitalRead(DOWN_BUTTON_PIN) == LOW) {
    decrementDate(alarmTime, 1);
  }
}

void handleSettingAlarmTimeButtons() {
  if (digitalRead(UP_BUTTON_PIN) == LOW) {
    incrementTime(alarmTime, 1);
  }

  if (digitalRead(DOWN_BUTTON_PIN) == LOW) {
    decrementTime(alarmTime, 1);
  }
}

void activateAlarm() {
  if (currentState == NORMAL && !digitalRead(LED_PIN)) {
    digitalWrite(LED_PIN, HIGH);  // Turn on the LED
    updateDisplay = false;  // Avoid display updates during melody playback
    rotateServo();  // Rotate the servo
    ringAlarm();
  }
}

void deactivateAlarm() {
  // Check if the LED has been on for more than 5 seconds
  if (digitalRead(LED_PIN) && millis() - alarmActivationTime >= LED_ON_TIME) {
    digitalWrite(LED_PIN, LOW);  // Turn off the LED
    alarmActivationTime = 0;  // Reset the activation time
    noTone(BUZZER_PIN);  // Turn off the buzzer
  }
}

bool checkAlarmTimeReached(const DateTime &current, const DateTime &alarm) {
  // Check if all components are equal except for seconds
  return (current.year() == alarm.year() &&
          current.month() == alarm.month() &&
          current.day() == alarm.day() &&
          current.hour() == alarm.hour() &&
          current.minute() == alarm.minute());
}

void incrementDate(DateTime &dateTime, int days) {
  dateTime = dateTime + TimeSpan(days, 0, 0, 0);
}

void decrementDate(DateTime &dateTime, int days) {
  dateTime = dateTime - TimeSpan(days, 0, 0, 0);
}

void incrementTime(DateTime &dateTime, int minutes) {
  if (currentState == SETTING_ALARM_HOUR) {
    dateTime = dateTime + TimeSpan(0, minutes, 0, 0);
  } else if (currentState == SETTING_ALARM_MINUTE) {
    dateTime = dateTime + TimeSpan(0, 0, minutes, 0);
  }
}

void decrementTime(DateTime &dateTime, int minutes) {
  if (currentState == SETTING_ALARM_HOUR) {
    dateTime = dateTime - TimeSpan(0, minutes, 0, 0);
  } else if (currentState == SETTING_ALARM_MINUTE) {
    dateTime = dateTime - TimeSpan(0, 0, minutes, 0);
  }
}

String dayStr(uint8_t day) {
  switch (day) {
    case 0:
      return "Sunday";
    case 1:
      return "Monday";
    case 2:
      return "Tuesday";
    case 3:
      return "Wednesday";
    case 4:
      return "Thursday";
    case 5:
      return "Friday";
    case 6:
      return "Saturday";
    default:
      return "Unknown";
  }
}

void displayNormalView(DateTime &currentTime) {
  display.clearDisplay();
  
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);

  display.print(currentTime.year(), DEC);
  display.print('/');
  display.print(currentTime.month(), DEC);
  display.print('/');
  display.print(currentTime.day(), DEC);
  display.print(" ");
  display.print(dayStr(currentTime.dayOfTheWeek()));

  display.setTextSize(2);
  display.setCursor(0, 18);

  display.print(currentTime.hour(), DEC);
  display.print(':');
  printTwoDigits(currentTime.minute());
  display.print(':');
  printTwoDigits(currentTime.second());
}

void displaySettingAlarmView(DateTime &alarmTime) {
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);

  switch (currentState) {
    case SETTING_ALARM_DATE:
      display.print("Setting Date:");
      display.setCursor(0, 20);
      display.print(alarmTime.year(), DEC);
      display.print('/');
      display.print(alarmTime.month(), DEC);
      display.print('/');
      display.print(alarmTime.day(), DEC);
      display.print(" ");
      display.print(dayStr(alarmTime.dayOfTheWeek()));
      break;
    case SETTING_ALARM_HOUR:
      display.print("Setting Hour:");
      display.setCursor(0, 20);
      display.print(alarmTime.hour(), DEC);
      break;
    case SETTING_ALARM_MINUTE:
      display.print("Setting Minute:");
      display.setCursor(0, 20);
      display.print(alarmTime.hour(), DEC);
      display.print(':');
      printTwoDigits(alarmTime.minute());
      break;
    case SETTING_ALARM_CONFIRM:
      display.print("Press OK to Confirm");
      display.setCursor(0, 40);
      display.print("Alarm set for: ");
      display.print(alarmTime.year(), DEC);
      display.print('/');
      display.print(alarmTime.month(), DEC);
      display.print('/');
      display.print(alarmTime.day(), DEC);
      display.print(" ");
      display.print(dayStr(alarmTime.dayOfTheWeek()));
      display.print(" ");
      display.print(alarmTime.hour(), DEC);
      display.print(':');
      printTwoDigits(alarmTime.minute());
      display.print(':');
      printTwoDigits(alarmTime.second());
      break;
  }
}

void printTwoDigits(int number) {
  if (number < 10) {
    display.print("0");
  }
  display.print(number);
}

void ringAlarm() {
  tone(BUZZER_PIN, HIGH); // Start the buzzer tone
  delay(5000); // Ring the alarm for 5 seconds
  digitalWrite(BUZZER_PIN, LOW); // Turn off the buzzer
}

void rotateServo() {
   servoMotor.attach(SERVO_PIN); // Use the correct pin
   servoMotor.write(0);   // Move to 0 degrees
  delay(1000);
  servoMotor.write(90);  // Move to 90 degrees
  delay(1000);
}