#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <EEPROM.h>
#include <RTClib.h>

// Pin definitions
const int menuButtonPin = 2;
const int upButtonPin = 3;
const int downButtonPin = 4;
const int setButtonPin = 5;
const int relayPin = 6;

// Create LCD and RTC objects
LiquidCrystal_I2C lcd(0x27, 16, 2);  // Adjust I2C address if needed
RTC_DS3231 rtc;

struct AlarmEvent {
  uint8_t hour;
  uint8_t minute;
};

AlarmEvent alarms[10];  // Array to store 10 alarm events

int currentMenu = 0;  // 0: Time, 1: Alarm Settings
int selectedAlarm = 0;  // Index of selected alarm event
bool isSettingTime = true;
bool settingHour = true;  // Toggle between hour and minute settings

// Variables to hold the last displayed information
String lastDisplay = "";
int lastAlarm = -1;

// Buzzer control variables
bool buzzerOn = false;
unsigned long buzzerStartTime = 0;
const unsigned long buzzerDuration = 5000;  // Buzzer duration in milliseconds

// Add a new variable to store the alarm duration
unsigned long alarmDuration = 10000; // 10 seconds
unsigned long alarmStartTime = 0;

void setup() {
  pinMode(menuButtonPin, INPUT_PULLUP);
  pinMode(upButtonPin, INPUT_PULLUP);
  pinMode(downButtonPin, INPUT_PULLUP);
  pinMode(setButtonPin, INPUT_PULLUP);
  pinMode(relayPin, OUTPUT);

  digitalWrite(relayPin, LOW);

  lcd.init();
  lcd.backlight();

  if (!rtc.begin()) {
    lcd.clear();
    lcd.print("RTC not found!");
    while (1);
  }

  // Load alarms from EEPROM
  for (int i = 0; i < 10; i++) {
    alarms[i].hour = EEPROM.read(i * 2);
    alarms[i].minute = EEPROM.read(i * 2 + 1);
  }

  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("    PISD SHS");
  lcd.setCursor(0,1);
  lcd.print("AUTO BELL ALARM");
  delay(2000);
}

void loop(){
  // Read button states
  bool menuButtonState = digitalRead(menuButtonPin) == LOW;
  bool upButtonState = digitalRead(upButtonPin) == LOW;
  bool downButtonState = digitalRead(downButtonPin) == LOW;
  bool setButtonState = digitalRead(setButtonPin) == LOW;

  // Handle menu navigation
  if (menuButtonState) {
    digitalWrite(relayPin, LOW);
    delay(200);  // Debounce
    currentMenu = (currentMenu + 1) % 2;
    if (currentMenu == 1) {  // When in Alarm Settings menu, reset to first alarm
      selectedAlarm = 0;
    }
    while (digitalRead(menuButtonPin) == LOW);  // Wait until button is released
  }

  // Handle setting change
  if (setButtonState) {
    delay(200);  // Debounce
    if (currentMenu == 0) {
      isSettingTime = !isSettingTime;
    } else {
      if (settingHour) {
        settingHour = false;  // Switch to minute setting
      } else {
        // Save alarm settings
        EEPROM.write(selectedAlarm * 2, alarms[selectedAlarm].hour);
        EEPROM.write(selectedAlarm * 2 + 1, alarms[selectedAlarm].minute);
        settingHour = true;  // Reset to hour setting for the next alarm
        
        selectedAlarm++;  // Move to the next alarm
        if (selectedAlarm >= 10) {
          // All alarms set
          lcd.clear();
          lcd.print("ALARM SAVED!");
          delay(2000);  // Display the message for 2 seconds
          selectedAlarm = 0;  // Reset to the first alarm
          currentMenu = 0;  // Go back to time display
        }
      }
    }
    while (digitalRead(setButtonPin) == LOW);  // Wait until button is released
  }

  // Handle up/down buttons
  if (upButtonState) {
    delay(200);  // Debounce
    if (currentMenu == 0) {
      if (isSettingTime) {
        // Update time settings here (code for updating current time should be added)
      }
    } else {
      // Adjust alarm settings
      if (settingHour) {
        alarms[selectedAlarm].hour = (alarms[selectedAlarm].hour + 1) % 24;
      } else {
        alarms[selectedAlarm].minute = (alarms[selectedAlarm].minute + 1) % 60;
      }
    }
    while (digitalRead(upButtonPin) == LOW);  // Wait until button is released
  }

  if (downButtonState) {
    delay(200);  // Debounce
    if (currentMenu == 0) {
      if (isSettingTime) {
        // Update time settings here (code for updating current time should be added)
      }
    } else {
      // Adjust alarm settings
      if (settingHour) {
        alarms[selectedAlarm].hour = (alarms[selectedAlarm].hour - 1 + 24) % 24;
      } else {
        alarms[selectedAlarm].minute = (alarms[selectedAlarm].minute - 1 + 60) % 60;
      }
    }
    while (digitalRead(downButtonPin) == LOW);  // Wait until button is released
  }

  // Update LCD based on menu
  DateTime now = rtc.now();
  String displayText;

  if (currentMenu == 0) {
    if (isSettingTime) {
      displayText = "Time: ";
      displayText += format12Hour(now.hour()) + ":" + formatTime(now.minute()) + " " + (now.hour() < 12 ? "AM" : "PM");
      lcd.setCursor(0,1); // Set cursor to second line
      lcd.print(displayText); // Print the time on the second line
    } else {
      displayText = "Time: ";
      displayText += format12Hour(now.hour()) + ":" + formatTime(now.minute()) + " " + (now.hour() < 12 ? "AM" : "PM");
      lcd.setCursor(0,1); // Set cursor to second line
      lcd.print(displayText); // Print the time on the second line
    }
    lcd.setCursor(0, 0); // Set cursor to first line
    lcd.print("Date: ");
    lcd.println(formatDate(now)); // Print the date on the first line
  } else {
    lcd.setCursor(0, 0);
    lcd.print("SET ALARM " + String(selectedAlarm + 1)); // Display Alarm setting
    String timeText = format12Hour(alarms[selectedAlarm].hour) + ":" + formatTime(alarms[selectedAlarm].minute);
    String amPm = alarms[selectedAlarm].hour < 12 ? "AM" : "PM";
    
    lcd.setCursor(0, 1); // Set cursor to second line
    lcd.print(timeText + " " + amPm); // Print the time with AM/PM on the second line
    if (settingHour) {
      lcd.print("  Hour  "); // Append "(Hour)" if setting the hour
    } else {
      lcd.print(" Minute  "); // Append "(Minute)" if setting the minute
    }
  }

  // Only update the display if the text has changed
  if (displayText != lastDisplay || selectedAlarm != lastAlarm) {
    lcd.clear();
    lcd.print(displayText);
    lastDisplay = displayText;
    lastAlarm = selectedAlarm;
  }

  // Check alarms and control buzzer
  if (!buzzerOn) {
    for (int i = 0; i < 10; i++) {
      if (alarms[i].hour == now.hour() && alarms[i].minute == now.minute()) {
        buzzerOn = true;
        alarmStartTime = millis();  // Store the start time of the alarm
        lcd.setCursor(0,1);
        lcd.print("  Alarm is ON..");
        digitalWrite(relayPin, HIGH);  // Turn on the buzzer
        delay(10000);
        digitalWrite(relayPin, LOW);
        delay(50000);
        break;
      }
    }
  } else {
    // Check if the alarm has been active for the specified duration
    if (millis() - alarmStartTime >= alarmDuration) {
      buzzerOn = false;
      digitalWrite(relayPin, LOW);  // Turn off the buzzer
    }
  }
}

// Helper function to format time with leading zeros
String formatTime(int value) {
  if (value < 10) {
    return"0" + String(value);
  } else {
    return String(value);
  }
}

// Helper function to convert 24-hour format to 12-hour format
String format12Hour(int hour) {
  if (hour == 0) return"12";  // Midnight
  if (hour == 12) return"12"; // Noon
  if (hour > 12) return String(hour - 12);  // PM times
  return String(hour);  // AM times
}

// Helper function to format date
String formatDate(DateTime now) {
  return String(now.day(), DEC) + "/" + String(now.month(), DEC) + "/" + String(now.year(), DEC);
}