//Include needed libraries
#include <PubSubClient.h>
#include <WiFi.h>
#include <string>
#define PIN_LED 15 //PIN USED FOR LED

#define MQTT_TOPIC "/polimi/iot/22-23/temperature" //the MQTT topic
#define MQTT_CLIENT_ID "iot-polimi-palmese-sub1" // the MQTT client identifier for connection

char strTemperature[10] = "24.5"; //string where we store the temperature for subscription
float threshold = 24.0;
WiFiClient espClient;
PubSubClient mqtt_client(espClient);


void callback(char* topic, byte* payload, unsigned int length) {
  memcpy(strTemperature,payload,length);
  Serial.println(strTemperature);
}

void setup() {
  Serial.begin(115200);
  //init pins
  pinMode(PIN_LED, OUTPUT);

   // Setup Wi-Fi
  WiFi.mode(WIFI_STA);
  WiFi.begin("Wokwi-GUEST", "");

  delay(1000);

  // Setup MQTT
  mqtt_client.setServer("test.mosquitto.org", 1883);
  mqtt_client.setCallback(callback);      //Set the callback for the subscription
  mqtt_client.connect(MQTT_CLIENT_ID);    //connect to broker
  delay(1000);
  mqtt_client.subscribe(MQTT_TOPIC);      //subscribe to topic
  
}

void loop() {
  mqtt_client.loop();
  double temp = std::stod(strTemperature);
  if(temp > threshold)
    digitalWrite(PIN_LED,HIGH);
  else
    digitalWrite(PIN_LED,LOW);
}