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

// Pin definitions
// DHT22 temperature/humidity sensor
#define DHTPIN 15 // Data pin -> GPIO15
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

// Ultrasonic (HC-SR04) sensor pins
const int trigPin = 26;
const int echoPin = 25;

// LEDs and buzzer for alerts
const int greenPin = 14;
const int orangePin = 27;
const int redPin = 12;
const int buzzPin = 13;

// I2C LCD (address 0x27, 16x2)
LiquidCrystal_I2C lcd(0x27, 16, 2);

// 🌧️ Rain sensor (Potentiometer simulation)
const int rainPin = 34; // Analog pin
int rainValue = 0;

// Global state
float temperature;
float humidity;
long duration;
long distance;

void setup() {
  Serial.begin(115200);

  // Initialize pins
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(orangePin, OUTPUT);
  pinMode(redPin, OUTPUT);
  pinMode(buzzPin, OUTPUT);

  // Rain pin
  pinMode(rainPin, INPUT);

  // Initialize sensors and LCD
  dht.begin();
  lcd.init();
  lcd.backlight();

  // Show a startup message
  lcd.setCursor(0, 0);
  lcd.print("Flood Detection");
  lcd.setCursor(0, 1);
  lcd.print("System... Online");
  delay(2000);
}

void loop() {
  // Read sensors, update display, and handle alerts
  readSensors();
  updateLCD();
  triggerAlerts();
}

void readSensors() {
  // Read temperature and humidity from DHT22
  humidity = dht.readHumidity();
  temperature = dht.readTemperature();

  // Abort if sensor read failed
  if (isnan(humidity) || isnan(temperature)) {
    Serial.println("Failed to read DHT sensor");
    return;
  }

  // Read Ultrasonic Sensor
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  duration = pulseIn(echoPin, HIGH);
  distance = duration * 0.034 / 2; // Calculate distance in cm

  // 🌧️ Read Rain Sensor (Potentiometer)
  rainValue = analogRead(rainPin);
  Serial.print("Rain Value: ");
  Serial.println(rainValue);
}

void updateLCD() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("T:");
  lcd.print(temperature);
  lcd.print(" H:");
  lcd.print(humidity);

  lcd.setCursor(0, 1);
  lcd.print("W:");
  lcd.print(distance);
  lcd.print(" R:");
  lcd.print(rainValue);
}

void triggerAlerts() {
  // Shorter distance means more water (higher risk)

  if (distance <= 5) {
    // RED: dangerous
    lcd.setCursor(14, 0);
    lcd.print("!!");
    digitalWrite(redPin, HIGH);
    digitalWrite(orangePin, LOW);
    digitalWrite(greenPin, LOW);
    digitalWrite(buzzPin, HIGH); // steady tone
  } else if (distance <= 20) {
    // ORANGE: warning
    digitalWrite(redPin, LOW);
    digitalWrite(orangePin, HIGH);
    digitalWrite(greenPin, LOW);

    // short beep
    digitalWrite(buzzPin, HIGH);
    delay(100);
    digitalWrite(buzzPin, LOW);
  } else {
    // GREEN: safe
    digitalWrite(redPin, LOW);
    digitalWrite(orangePin, LOW);
    digitalWrite(greenPin, HIGH);
    digitalWrite(buzzPin, LOW);
  }
}