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

WiFiClient espClient;
PubSubClient client(espClient);

#define ssid "Wokwi-GUEST"
#define password ""
#define mqtt_server "test.mosquitto.org"
#define mqtt_topic "/MQTT/thanakrit"
String clientId = "mqtt-explorer-f275e0ec";

#define DHTPIN 15          // กำหนดหมายเลขขาที่เชื่อมต่อกับ DHT sensor
#define DHTTYPE DHT22      // หรือ DHT22 หรือ DHT21

DHT dht(DHTPIN, DHTTYPE);

void setup_wifi() {
  delay(200);
  Serial.println();
  Serial.println();
  Serial.print("Connecting to WiFi: ");
  Serial.println(ssid);
     
  WiFi.begin(ssid, password);   
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }     
  if(WiFi.status() == WL_CONNECTED){
    Serial.println("");
    Serial.println("ESP32 has connected to WiFi !!");  
    Serial.print("IP address : ");
    Serial.println(WiFi.localIP());  
  }
  else{
    Serial.println("\nFailed to connect to WiFi !!");
  } 
}

void reconnect() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    clientId += String(random(0xffff), HEX);
    
    if (client.connect(clientId.c_str())) {
      Serial.println("Connected");
      client.subscribe(mqtt_topic);
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

void setup() {
  Serial.begin(115200);
  setup_wifi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
  dht.begin();
}

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

  float temperature = dht.readTemperature(); // อ่านค่าอุณหภูมิจาก DHT sensor
  float humidity = dht.readHumidity();       // อ่านค่าความชื้นจาก DHT sensor

  String payload = "{\"temperature\":" + String(temperature) + ",\"humidity\":" + String(humidity) + "}";
  
  boolean dataout = client.publish(mqtt_topic, payload.c_str());

  Serial.println("\n----------------------------------------------");
  Serial.println("Temperature: " + String(temperature) + " °C");
  Serial.println("Humidity: " + String(humidity) + " %");
  Serial.println("Json Packages: " + payload);
  Serial.println("Publish Information: Data Sent");
  Serial.println("----------------------------------------------");

  delay(2000);
}

void callback(char* topic, byte* payload, unsigned int length) {
  Serial.println("\n----------------------------------------------");
  Serial.print("Message arrived in topic: ");
  Serial.println(topic);
  Serial.print("Subscribe Information: ");
  for (int i = 0; i < length; i++) {
    (char)payload[i];
    Serial.print((char)payload[i]);
  } 
  Serial.println();
}