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

// OLED Configuration
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// RTC Module
RTC_DS3231 rtc;

// Button Pins
#define BTN_INC 7    // Increment button
#define BTN_DEC 9    // Decrement button
#define BTN_MODE 10  // Change mode button

// Alarm Pin
#define ALARM_PIN 8

// Modes for adjusting time and alarms
enum Mode { YEAR, MONTH, DAY, HOUR, MINUTE, SET_ALARM };
Mode currentMode = YEAR;

// Time variables
int year = 2024, month = 12, day = 2, hour = 20, minute = 7, second = 0; // Set to 8:07 PM

// Alarm times and labels (24-hour format)
const int alarmCount = 6;
int alarmTimes[alarmCount][2] = {
  {8, 0},    // Breakfast
  {9, 15},   // Get ready for ITI
  {12, 1},   // Lunch
  {13, 0},   // Lunch end
  {17, 30},  // Tea
  {19, 0}    // Dinner
};
const char* alarmLabels[alarmCount] = {
  "Breakfast", "Get Ready for ITI", "Lunch", "Lunch End", "Tea", "Dinner"
};

bool isHoliday = false; // Flag for holidays
String currentAlarmStatus = "No Alarm"; // To display current alarm status

void setup() {
  // Initialize Serial Monitor
  Serial.begin(9600);

  // Initialize OLED
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    while (1);
  }
  display.clearDisplay();

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

  // Initialize buttons
  pinMode(BTN_INC, INPUT_PULLUP);
  pinMode(BTN_DEC, INPUT_PULLUP);
  pinMode(BTN_MODE, INPUT_PULLUP);

  // Initialize Alarm
  pinMode(ALARM_PIN, OUTPUT);
  digitalWrite(ALARM_PIN, LOW);

  // Set RTC to start at 8:07 PM, December 2, 2024
  rtc.adjust(DateTime(year, month, day, hour, minute, second));
}

void loop() {
  DateTime now = rtc.now();

  // Check buttons for manual adjustments
  if (digitalRead(BTN_INC) == LOW) {
    incrementValue();
    delay(200); // Debounce
  }
  if (digitalRead(BTN_DEC) == LOW) {
    decrementValue();
    delay(200); // Debounce
  }
  if (digitalRead(BTN_MODE) == LOW) {
    changeMode();
    delay(200); // Debounce
  }

  // Check and trigger alarm
  triggerAlarm(now);

  // Update OLED
  displayStatus(now);
}

void incrementValue() {
  switch (currentMode) {
    case YEAR: year++; break;
    case MONTH: month = (month % 12) + 1; break;
    case DAY: day = (day % 31) + 1; break;
    case HOUR: hour = (hour + 1) % 24; break;
    case MINUTE: minute = (minute + 1) % 60; break;
    case SET_ALARM:
      alarmTimes[0][0]++; // Increment the first alarm for testing
      break;
  }
}

void decrementValue() {
  switch (currentMode) {
    case YEAR: year--; break;
    case MONTH: month = (month == 1) ? 12 : month - 1; break;
    case DAY: day = (day == 1) ? 31 : day - 1; break;
    case HOUR: hour = (hour == 0) ? 23 : hour - 1; break;
    case MINUTE: minute = (minute == 0) ? 59 : minute - 1; break;
    case SET_ALARM:
      alarmTimes[0][0]--; // Decrement the first alarm for testing
      break;
  }
}

void changeMode() {
  currentMode = static_cast<Mode>((currentMode + 1) % 6);
}

void displayStatus(DateTime now) {
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);

  // Display current time
  display.print("Date: ");
  display.print(now.year());
  display.print('/');
  display.print(now.month());
  display.print('/');
  display.println(now.day());

  display.print("Time: ");
  if (now.hour() < 10) display.print('0');
  display.print(now.hour());
  display.print(':');
  if (now.minute() < 10) display.print('0');
  display.print(now.minute());
  display.print(':');
  if (now.second() < 10) display.print('0');
  display.println(now.second());

  // Display current mode
  display.print("Mode: ");
  switch (currentMode) {
    case YEAR: display.println("Year"); break;
    case MONTH: display.println("Month"); break;
    case DAY: display.println("Day"); break;
    case HOUR: display.println("Hour"); break;
    case MINUTE: display.println("Minute"); break;
    case SET_ALARM: display.println("Set Alarm"); break;
  }

  // Display current alarm status
  display.setCursor(0, 48);
  display.print("Alarm: ");
  display.println(currentAlarmStatus);

  display.display();
}

void triggerAlarm(DateTime now) {
  // Check if today is Sunday or a holiday
  if (now.dayOfTheWeek() == 0 || isHoliday) {
    digitalWrite(ALARM_PIN, LOW); // No alarm
    currentAlarmStatus = "Holiday";
    return;
  }

  // Check if the current time matches any alarm time
  currentAlarmStatus = "No Alarm"; // Default status
  for (int i = 0; i < alarmCount; i++) {
    if (now.hour() == alarmTimes[i][0] && now.minute() == alarmTimes[i][1]) {
      digitalWrite(ALARM_PIN, HIGH); // Turn alarm on
      currentAlarmStatus = alarmLabels[i]; // Update alarm status
      delay(180000);                      // Keep alarm on for 3 minutes
      digitalWrite(ALARM_PIN, LOW);       // Turn alarm off
    }
  }
}