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

const char* ssid = "Wokwi-GUEST";
const char* password = "";

const char* mqtt_server = "test.mosquitto.org";

WiFiClient espClient;
PubSubClient client(espClient);

#define LED_BUILTIN 15
#define LED_BUILTIN 5
#define LED_BUILTIN 4
#define LED_BUILTIN 2

unsigned long lastMsg = 0;
#define MSG_BUFFER_SIZE	(50)

char msg[MSG_BUFFER_SIZE];
int value = 0;

void setup_wifi();
void callback(char* topic, byte* payload, unsigned int length);
void reconnect();

void setup()
{
  pinMode(BUILTIN_LED, OUTPUT);     // Initialize the LED pin as an output
  Serial.begin(115200);
  setup_wifi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
}

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

}

//==== implementação das funções =====

void setup_wifi() 
{
  delay(10);
  // We start by connecting to a WiFi network
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) 
  {
    delay(500);
    Serial.print(".");
  }

  randomSeed(micros());

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void callback(char* topic, byte* payload, unsigned int length) 
{
  Serial.print("Mensagem recebida [");
  Serial.print(topic);
  Serial.print("] ");
  for (int i = 0; i < length; i++) 
  {
    Serial.print((char)payload[i]);
  }
  Serial.println();

  //=== TRATAMENTO DAS MENSAGENS RECEBIDAS (MQTT) =================
  if ( (char)payload[0] == 'o'&(char)payload[1] == 'l'&(char)payload[2] == 'a' )
  {
    client.publish("mba2_sub", "Olá, tudo bem?");
  } else {
    client.publish("mba2_sub", "Não entendi!!                                              ");
  }
}

void reconnect() 
{
  // Loop until we're reconnected
  while (!client.connected()) 
  {
    Serial.print("Attempting MQTT connection...");
    // Create a random client ID
    String clientId = "ESP32Client-";
    clientId += String(random(0xffff), HEX);
    // Attempt to connect
    if (client.connect(clientId.c_str())) 
    {
      Serial.println("connected");
      // Once connected, publish an announcement...
      //client.publish("outOutTopic", "starting....");
      // ... and resubscribe
      client.subscribe("mba2_pub");
    } else {
            Serial.print("failed, rc=");
            Serial.print(client.state());
            Serial.println(" try again in 5 seconds");
            delay(5000);
    }
  }//end while
}//end reconnect