#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <DHT.h>
#include <RTClib.h>  // Include the RTClib library for DS1307

// Pin configuration
#define DHTPIN 2
#define MQ2PIN A1 // Analog pin for MQ2 sensor
#define BUZZERPIN 3
#define BUTTON1PIN 4
#define BUTTON2PIN 5
#define BUTTON3PIN 6
#define BUTTON4PIN 7 // Mute button

// DHT setup
#define DHTTYPE DHT22  // Change to DHT22
DHT dht(DHTPIN, DHTTYPE);

// LCD setup
#define I2C_ADDR 0x27
#define LCD_COLUMNS 20
#define LCD_LINES 4
LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

// RTC setup
RTC_DS1307 rtc; // Initialize the DS1307 RTC

// Thresholds
const int temperatureThresholds[] = {85, 95, 90, 87}; // Example thresholds, replace as needed
const int MQ2Threshold = 800;  // Set MQ2 threshold for fire detection

// Variables
int currentPage = 1; 
bool buzzerActive = false;
bool buzzerMQ2Active = false;
bool buzzerMuted = false;
unsigned long buzzerStartTime = 0;
int currentThresholdIndex = 0;
unsigned long lastButtonPress = 0;
const unsigned long debounceDelay = 300;
unsigned long lastDHTRead = 0;
const unsigned long DHTReadInterval = 500;

// Function declarations
void updateDisplay(float temperature = NAN, float humidity = NAN, int mq2Value = -1);
void togglePage();
void manageBuzzer(float temperature, int mq2Value);
void scrollPresets();
void muteBuzzer();
void printDateTime();

// Initialize setup()
void setup() {
  lcd.init(); // Initialize the LCD
  lcd.backlight(); // Turn on the backlight

  dht.begin(); // Initialize the DHT sensor
  rtc.begin(); // Initialize the RTC
  if (!rtc.isrunning()) {
    rtc.adjust(DateTime(2023, 10, 13, 0, 0, 0)); // Set the RTC to the current date and time if not running
  }

  pinMode(MQ2PIN, INPUT);
  pinMode(BUZZERPIN, OUTPUT);
  pinMode(BUTTON1PIN, INPUT_PULLUP);
  pinMode(BUTTON2PIN, INPUT_PULLUP);
  pinMode(BUTTON3PIN, INPUT_PULLUP);
  pinMode(BUTTON4PIN, INPUT_PULLUP);

  lcd.setCursor(0, 0);
  lcd.print("Welcome to your");
  lcd.setCursor(0, 1);
  lcd.print("Smart 3D Enclosure");
  lcd.setCursor(0, 2);
  lcd.print("Version 4.1.0");
  delay(5000); // Display for 5 seconds
  lcd.clear();

  updateDisplay(); // Display initial page
}

void loop() {
  unsigned long currentMillis = millis();
  
  if (digitalRead(BUTTON1PIN) == LOW && (currentMillis - lastButtonPress) > debounceDelay) {
    lastButtonPress = currentMillis;
    togglePage();
  }

  if (digitalRead(BUTTON2PIN) == LOW && (currentMillis - lastButtonPress) > debounceDelay) {
    lastButtonPress = currentMillis;
    lcd.clear();
  }

  if (digitalRead(BUTTON3PIN) == LOW && (currentMillis - lastButtonPress) > debounceDelay) {
    lastButtonPress = currentMillis;
    scrollPresets();
  }

  if (digitalRead(BUTTON4PIN) == LOW && (currentMillis - lastButtonPress) > debounceDelay) {
    lastButtonPress = currentMillis;
    muteBuzzer();
  }

  if (currentMillis - lastDHTRead >= DHTReadInterval) {
    lastDHTRead = currentMillis;
    float temperature = dht.readTemperature(true);
    float humidity = dht.readHumidity();
    int mq2Value = analogRead(MQ2PIN);

    manageBuzzer(temperature, mq2Value); // Manage buzzer for fire alarm
    updateDisplay(temperature, humidity, mq2Value);
  }

  delay(100); // Short delay for stability
}

void togglePage() {
  currentPage = (currentPage == 1) ? 2 : (currentPage == 2) ? 3 : (currentPage == 3) ? 4 : 1;
  lcd.clear(); // Clear the display to avoid overlapping content
  updateDisplay(); // Update display based on the new page
}

void manageBuzzer(float temperature, int mq2Value) {
  unsigned long currentTime = millis();

  // Fire alarm conditions
  if (temperature >= 121.0 && mq2Value >= MQ2Threshold) {
    // Clear the display and show fire alert
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("FIRE ALERT!");
    lcd.setCursor(0, 1);
    lcd.print("Evacuate Now!");

    // Buzzer logic for fire alert
    if (!buzzerMuted) {
      tone(BUZZERPIN, 1000); // Turn on buzzer
      delay(1000);           // Buzz for 1 second
      noTone(BUZZERPIN);     // Turn off buzzer
      delay(500);            // Wait for half a second
    }
  } else {
    if (!buzzerMuted) {
      noTone(BUZZERPIN); // Turn off buzzer if not in fire state
    }
  }
}

void updateDisplay(float temperature, float humidity, int mq2Value) {
  DateTime now = rtc.now();
  
  if (currentPage == 1) {
    lcd.setCursor(0, 0);
    lcd.print("Temp: ");
    if (isnan(temperature)) {
      lcd.print("NA");
    } else {
      lcd.print(temperature);
      lcd.print(" F");
    }

    lcd.setCursor(0, 1);
    lcd.print("Hum: ");
    if (isnan(humidity)) {
      lcd.print("NA");
    } else {
      lcd.print(humidity);
      lcd.print(" %");
    }

    lcd.setCursor(0, 2);
    lcd.print("MQ2: ");
    if (mq2Value < 0) {
      lcd.print("NA");
    } else {
      lcd.print(mq2Value);
    }

    lcd.setCursor(0, 3);
    printDateTime(); // Print date and time
  } 
  else if (currentPage == 2) {
       unsigned long uptimeMillis = millis();
    unsigned long uptimeSeconds = uptimeMillis / 1000;
    unsigned long uptimeMinutes = uptimeSeconds / 60;
    unsigned long uptimeHours = uptimeMinutes / 60;
    unsigned long seconds = uptimeSeconds % 60;
    unsigned long minutes = uptimeMinutes % 60;
    unsigned long hours = uptimeHours;

    lcd.setCursor(0, 0);
    lcd.print("Uptime: ");
    lcd.print(hours);
    lcd.print("h ");
    lcd.print(minutes);
    lcd.print("m ");
    lcd.print(seconds);
    lcd.print("s");

    lcd.setCursor(0, 1);
    lcd.print("Preset Temp: ");
    lcd.print(temperatureThresholds[currentThresholdIndex]);

    lcd.setCursor(0, 2);
    lcd.print("Temp: ");
    if (isnan(temperature)) {
      lcd.print("NA");
    } else {
      lcd.print(temperature);
      lcd.print(" F");
    }

    lcd.setCursor(0, 3);
    lcd.print("Page 2");
  } 
  else if (currentPage == 3) {
    lcd.setCursor(0, 0);
    lcd.print("Made by Diego R");

    lcd.setCursor(0, 1);
    lcd.print("Jimenez");

    lcd.setCursor(0, 2);
    lcd.print("Buzzer: ");
    lcd.print(buzzerMuted ? "Muted" : "Active");

    lcd.setCursor(0, 3);
    lcd.print("Page 3");
  } 
  else if (currentPage == 4) {
    lcd.setCursor(0, 0);
    lcd.print("Date: ");
    printDateTime(now);

    lcd.setCursor(0, 1);
    lcd.print("Time: ");
    lcd.print(now.Hour());
    lcd.print(":");
    if (now.Minute() < 10) lcd.print("0");
    lcd.print(now.Minute());

    lcd.setCursor(0, 2);
    lcd.print("v 4.1.0");

    lcd.setCursor(0, 3);
    lcd.print("Page 4");
  }
}

// Print date and time on the LCD
void printDateTime() {
  DateTime now = rtc.now();
  lcd.print(now.year(), DEC);
  lcd.print('/');
  lcd.print(now.month(), DEC);
  lcd.print('/');
  lcd.print(now.day(), DEC);
  lcd.print(' ');
  lcd.print(now.hour(), DEC);
  lcd.print(':');
  lcd.print(now.minute(), DEC);
  lcd.print(':');
  lcd.print(now.second(), DEC);
}

// Scroll through preset values
void scrollPresets() {
  currentThresholdIndex = (currentThresholdIndex + 1) % (sizeof(temperatureThresholds) / sizeof(temperatureThresholds[0]));
  lcd.clear();
  lcd.print("Current Threshold: ");
  lcd.print(temperatureThresholds[currentThresholdIndex]);
}

// Mute the buzzer
void muteBuzzer() {
  buzzerMuted = !buzzerMuted; // Toggle mute state
  if (buzzerMuted) {
    lcd.setCursor(0, 0);
    lcd.print("Buzzer Muted    ");
  } else {
    lcd.setCursor(0, 0);
    lcd.print("Buzzer Unmuted  ");
  }
}