#include <WiFi.h>
#include <WiFiClientSecure.h>
#include <PubSubClient.h>
#include <DHT.h>

// Wi-Fi and AWS IoT configuration
const char* ssid = "YOUR_WIFI_SSID";
const char* password = "YOUR_WIFI_PASSWORD";
const char* awsEndpoint = "YOUR_AWS_IOT_ENDPOINT";  // e.g., "xxxxxx.iot.us-east-1.amazonaws.com"

// Device certificate details
const char* awsCertCa = "YOUR_CA_CERT";  // Root CA certificate
const char* awsCertCrt = "YOUR_DEVICE_CERT";  // Device certificate
const char* awsCertPrivate = "YOUR_PRIVATE_KEY";  // Device private key

#define DHTPIN 25      
#define DHTTYPE DHT22  
DHT dht(DHTPIN, DHTTYPE);

WiFiClientSecure net;
PubSubClient client(net);

void connectAWS() {
  net.setCACert(awsCertCa);
  net.setCertificate(awsCertCrt);
  net.setPrivateKey(awsCertPrivate);

  // Connect to AWS IoT
  client.setServer(awsEndpoint, 8883);
  while (!client.connected()) {
    Serial.println("Connecting to AWS IoT...");
    if (client.connect("ESP32_DHT22")) {  // Device ID
      Serial.println("Connected to AWS IoT");
    } else {
      Serial.print("Failed to connect. State: ");
      Serial.print(client.state());
      delay(2000);
    }
  }
}

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

  // Connect to Wi-Fi
  Serial.print("Connecting to Wi-Fi...");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("Connected to Wi-Fi");

  // Connect to AWS IoT
  connectAWS();
}

void loop() {
  if (!client.connected()) {
    connectAWS();
  }
  client.loop();

  float humidity = dht.readHumidity();
  float temperature = dht.readTemperature();

  // Check if reading was successful
  if (isnan(humidity) || isnan(temperature)) {
    Serial.println("Failed to read from DHT22 sensor!");
    return;
  }

  // Print the values to Serial Monitor
  Serial.print("Humidity: ");
  Serial.print(humidity);
  Serial.print(" %\t");
  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.println(" °C");

  // Create JSON payload
  String payload = "{\"temperature\": ";
  payload += String(temperature);
  payload += ", \"humidity\": ";
  payload += String(humidity);
  payload += "}";

  // Publish data to AWS IoT Core
  if (client.publish("esp32/dht22", payload.c_str())) {
    Serial.println("Data sent to AWS IoT Core.");
  } else {
    Serial.println("Failed to send data to AWS IoT Core.");
  }

  delay(2000);  // Delay between readings
}