#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <DHT.h>

#define DHTPIN 4      // Pin connected to the DHT sensor
#define DHTTYPE DHT22 // Type of the DHT sensor

LiquidCrystal_I2C lcd(0x27, 16, 2); // Initialize the LCD with I2C address 0x27

#define TRIG_PIN 13   // TRIG pin of the ultrasonic sensor
#define ECHO_PIN 12   // ECHO pin of the ultrasonic sensor

#define GREEN_LED_PIN 2   // Green LED pin
#define ORANGE_LED_PIN 14 // Orange LED pin
#define RED_LED_PIN 15    // Red LED pin
#define BUZZER_PIN 27     // Buzzer pin

DHT dht(DHTPIN, DHTTYPE); // Initialize the DHT sensor

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

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

  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(GREEN_LED_PIN, OUTPUT);
  pinMode(ORANGE_LED_PIN, OUTPUT);
  pinMode(RED_LED_PIN, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);

  dht.begin();

  digitalWrite(GREEN_LED_PIN, LOW);
  digitalWrite(ORANGE_LED_PIN, LOW);
  digitalWrite(RED_LED_PIN, LOW);
  digitalWrite(BUZZER_PIN, LOW);

  lcd.setCursor(0, 0);
  lcd.print("Flood Monitoring");
  lcd.setCursor(0, 1);
  lcd.print("Alerting System");
  delay(5000);
  lcd.clear();
}

void loop() {
  float temperature = dht.readTemperature();
  float humidity = dht.readHumidity();

  if (isnan(temperature) || isnan(humidity)) {
    lcd.print("ERROR");
    return;
  }

  long duration, distance;
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  duration = pulseIn(ECHO_PIN, HIGH);
  distance = duration * 0.034 / 2;

  int waterLevelPercentage = map(distance, 2, 400, 0, 100);
  waterLevelPercentage = constrain(waterLevelPercentage, 0, 100);

  Serial.print("Humidity: ");
  Serial.print(humidity);
  Serial.print("%  Temperature: ");
  Serial.print(temperature);
  Serial.print("C  Water Level: ");
  Serial.print(waterLevelPercentage);
  Serial.println("%");

  lcd.setCursor(0, 0);
  lcd.print("Temperature:");
  lcd.setCursor(0, 1);
  lcd.print("Humidity   :");
  lcd.setCursor(12, 0);
  lcd.print(temperature);
  lcd.setCursor(12, 1);
  lcd.print(humidity);
  delay(1000);
  lcd.clear();

  lcd.print("Water Level:");
  lcd.print(waterLevelPercentage);
  lcd.print("%  ");

  if (distance <= 3) {
    lcd.setCursor(0, 1);
    lcd.print("Red Alert!   ");
    digitalWrite(RED_LED_PIN, HIGH);
    digitalWrite(GREEN_LED_PIN, LOW);
    digitalWrite(ORANGE_LED_PIN, LOW);
    tone(BUZZER_PIN, 1000); // Turn on the buzzer
    delay(2000);
    noTone(BUZZER_PIN); // Turn off the buzzer
    delay(2000);
  } else if (distance <= 10) {
    lcd.setCursor(0, 1);
    lcd.print("Orange Alert!  ");
    digitalWrite(ORANGE_LED_PIN, HIGH);
    digitalWrite(RED_LED_PIN, LOW);
    digitalWrite(GREEN_LED_PIN, LOW);
    tone(BUZZER_PIN, 1000); // Turn on the buzzer
    delay(2000);
    noTone(BUZZER_PIN); // Turn off the buzzer
    delay(2000);
  } else {
    lcd.setCursor(0, 1);
    lcd.print("Green Alert!  ");
    digitalWrite(GREEN_LED_PIN, HIGH);
    digitalWrite(ORANGE_LED_PIN, LOW);
    digitalWrite(RED_LED_PIN, LOW);
    noTone(BUZZER_PIN); // Turn off the buzzer
  }
}