#include <WiFi.h>
#include "secrets.h"           
#include <WiFiClientSecure.h>
#include <PubSubClient.h>
#include <ArduinoJson.h>
#include <DHTesp.h>             

// Wi-Fi and AWS IoT settings
const int DHT_PIN = 15;         
DHTesp dhtSensor;
#define AWS_IOT_PUBLISH_TOPIC   "iotresc/pub"
#define AWS_IOT_SUBSCRIBE_TOPIC "iotresc/sub"
String h;                       
String t;                       

WiFiClientSecure net;
PubSubClient client(net);

// Connect to AWS IoT
void connectAWS() {
  WiFi.mode(WIFI_STA);          
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);  

  Serial.println("Connecting to Wi-Fi...");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nConnected to Wi-Fi!");

  // Configure WiFiClientSecure to use AWS IoT device credentials
  net.setCACert(AWS_CERT_CA);       // Root CA
  net.setCertificate(AWS_CERT_CRT); // Device Certificate
  net.setPrivateKey(AWS_CERT_PRIVATE); // Device Private Key

  // Connect to AWS IoT MQTT broker
  client.setServer(AWS_IOT_ENDPOINT, 8883);
  client.setCallback(messageHandler);

  Serial.println("Connecting to AWS IoT...");
  while (!client.connect(THINGNAME)) {
    Serial.print(".");
    delay(100);
  }

  if (!client.connected()) {
    Serial.println("AWS IoT Timeout!");
    return;
  }

  client.subscribe(AWS_IOT_SUBSCRIBE_TOPIC);  // Subscribe to topic
  Serial.println("\nAWS IoT Connected!");
}

// Publish sensor data to AWS IoT
void publishMessage() {
  StaticJsonDocument<200> doc;
  doc["humidity"] = h;
  doc["temperature"] = t;
  char jsonBuffer[512];
  serializeJson(doc, jsonBuffer); // Convert to JSON format

  client.publish(AWS_IOT_PUBLISH_TOPIC, jsonBuffer);  // Publish to MQTT topic
}

// Handle incoming MQTT messages
void messageHandler(char* topic, byte* payload, unsigned int length) {
  Serial.print("Incoming message from topic: ");
  Serial.println(topic);

  StaticJsonDocument<200> doc;
  deserializeJson(doc, payload);  // Parse incoming JSON message
  const char* message = doc["message"];
  Serial.println(message);
}

void setup() {
  Serial.begin(115200);
  Serial.println("Starting...");

  dhtSensor.setup(DHT_PIN, DHTesp::DHT22);  // Setup DHT sensor

  connectAWS();  // Connect to Wi-Fi and AWS IoT
}

void loop() {
  TempAndHumidity data = dhtSensor.getTempAndHumidity();  // Read sensor data

  h = String(data.humidity, 1);        // Humidity with 1 decimal place
  t = String(data.temperature, 2);     // Temperature with 2 decimal places

  Serial.println("Temp: " + t + "°C");
  Serial.println("Humidity: " + h + "%");
  Serial.println("---");

  publishMessage();                    // Send data to AWS IoT
  client.loop();                       // Keep MQTT client alive
  delay(5000);                         // Wait 5 seconds before next reading
}