#include <LiquidCrystal_I2C.h>
#include <DHTesp.h>
#include <WiFi.h>
#include <PubSubClient.h>
#include <OneWire.h>
#include <DallasTemperature.h>
#include <ESP32Servo.h>

// WiFi credentials
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// MQTT Broker
const char* mqtt_broker = "test.mosquitto.org"; // a Mosquitto Public Test Server
const int mqtt_port = 1883;
const char* mqtt_username = "";
const char* mqtt_password = "";

// MQTT topics
const char* tempTopic = "zied/temperature"; // to send temperature values to broker
const char* humTopic = "zied/humidity";     // to send humidity values to broker
const char* servoTopic = "zied/onoff";      // to control the servo

// Define pin constants
#define DHTpin 25   // Pin for DHT22 sensor
#define BUTTON 18   // Pin for push button
#define LED 23      // Pin for LED
#define BUZZER 4    // Pin for buzzer
#define ONE_WIRE_BUS 19 // Pin for OneWire bus
#define TRIG_PIN 5   // Pin for ultrasonic sensor trigger
#define ECHO_PIN 18  // Pin for ultrasonic sensor echo
#define SERVO_PIN 21 // Pin for servo

// Define thresholds for triggering the alarm
#define TEMPERATURE_THRESHOLD 45.0   // Temperature threshold in Celsius
#define HUMIDITY_THRESHOLD 50.0      // Humidity threshold in percentage
#define SOUND_SPEED 0.034 // Speed of sound in cm/ms

// Create instances
DHTesp dhtSensor;
LiquidCrystal_I2C lcd(0x27, 16, 2);
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);
Servo servoMotor;

// WiFi and MQTT clients
WiFiClient wifiClient;
PubSubClient mqttClient(wifiClient);

// Function to check if alarm conditions are met
bool isAlarmTriggered(float temperature, float humidity) {
  // Check if temperature exceeds the threshold
  if (temperature > TEMPERATURE_THRESHOLD || humidity > HUMIDITY_THRESHOLD) {
    return true;
  }
  return false;
}

// Function to connect to WiFi
void connectWiFi() {
  Serial.println("Connecting to WiFi...");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting...");
  }
  Serial.println("Connected to WiFi");
}

// Function to connect to MQTT broker
void connectMQTT() {
  Serial.println("Connecting to MQTT Broker...");
  mqttClient.setServer(mqtt_broker, mqtt_port);
  while (!mqttClient.connected()) {
    if (mqttClient.connect("ESP32Client", mqtt_username, mqtt_password)) {
      Serial.println("Connected to MQTT Broker");
    } else {
      Serial.print("MQTT connection failed, rc=");
      Serial.print(mqttClient.state());
      Serial.println(" Retrying in 5 seconds...");
      delay(5000);
    }
  }
}

// MQTT callback function
void callback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Message arrived on topic: ");
  Serial.print(topic);
  Serial.print(". Message: ");
  String message;
  for (int i = 0; i < length; i++) {
    Serial.print((char)payload[i]);
    message += (char)payload[i];
  }
  Serial.println();
  
  // Process the message based on the topic
  if (String(topic) == servoTopic) {
    if (message == "on") {
      servoMotor.write(90); // Turn on servo
    } else if (message == "off") {
      servoMotor.write(0);  // Turn off servo
    }
  }
}

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

  // Initialize LCD
  lcd.init();
  lcd.backlight();

  // Initialize DHT sensor
  dhtSensor.setup(DHTpin, DHTesp::DHT22);

  // Initialize OneWire bus and DallasTemperature sensors
  sensors.begin();

  // Set pin modes
  pinMode(LED, OUTPUT);
  pinMode(BUTTON, INPUT);
  pinMode(BUZZER, OUTPUT);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  
  // Attach servo to pin
  servoMotor.attach(SERVO_PIN);

  // Subscribe to MQTT topics
  mqttClient.subscribe(servoTopic);
  mqttClient.setCallback(callback);
}

void loop() {
  // Read temperature and humidity
  TempAndHumidity data = dhtSensor.getTempAndHumidity();
  float temperature = data.temperature;
  float humidity = data.humidity;

  // Display temperature and humidity on LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Temp: ");
  lcd.print(temperature);
  lcd.print("C");
  lcd.setCursor(0, 1);
  lcd.print("Humidity: ");
  lcd.print(humidity);
  lcd.print("%");

  // Check if alarm conditions are met
  if (isAlarmTriggered(temperature, humidity)) {
    // Turn on LED
    digitalWrite(LED, HIGH);

    // Play alarm sound effect
    for (int i = 0; i < 5; i++) {
      tone(BUZZER, 2000);  // Adjust frequency as needed
      delay(100);          // Adjust duration as needed
      noTone(BUZZER);
      delay(100);
    }

    // Turn off LED
    digitalWrite(LED, LOW);
  }

  // Publish temperature and humidity to MQTT broker
  if (mqttClient.connected()) {
    mqttClient.publish(tempTopic, String(temperature).c_str());
    mqttClient.publish(humTopic, String(humidity).c_str());
  }

  // Maintain MQTT connection
  if (!mqttClient.connected()) {
    connectMQTT();
  }

  // Check MQTT messages
  mqttClient.loop();

  // Delay before next iteration
  delay(2000);
}