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

#define ssid "Wokwi-GUEST"
#define password ""

const char *mqttBroker = "broker.hivemq.com";

WiFiClient wiFiClient;
PubSubClient mqttClient(wiFiClient);
unsigned long tempoUltimaMensagem;

#define RELAY_PIN 16 
#define DHTPIN 4
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

bool conectarWiFi()
{
    Serial.println("Tentando estabelecer uma conexao com a rede Wi-Fi...");
    const unsigned long tempoInicial = millis();
    WiFi.begin(ssid, password);
    do
    {
        if (WiFi.status() == WL_CONNECTED)
        {
            Serial.println("Conexao Wi-Fi estabelecida com sucesso!");
            return true;
        }
        delay(1000);
    } while ((millis() - tempoInicial) < 30000L);
    Serial.println("Impossivel estabelecer uma conexao com a rede Wi-Fi!");
    return false;
}

bool verificarWiFi()
{
    if (WiFi.status() == WL_CONNECTED)
        return true;
    Serial.println("Conexao Wi-Fi perdida.");
    WiFi.disconnect(true);
    delay(5000);
    return conectarWiFi();
}

bool conectarMQTT()
{
    Serial.println("Tentando estabelecer uma conexao com o broker MQTT...");
    const unsigned long tempoInicial = millis();
    char clientId[32];
    sprintf(clientId, "inteli_%02X%02X%02X%02X%02X%02X%02X%02X",
            random(256), random(256), random(256), random(256),
            random(256), random(256), random(256), random(256));
    do
    {
        if (mqttClient.connect(clientId))
        {
            if (!mqttClient.subscribe("dht_inteli")) #topic
            {
                Serial.println("Erro ao se inscrever em dht_inteli");
            }
            Serial.print("Conectado ao broker MQTT utilizando o client id ");
            Serial.print(clientId);
            Serial.println(", e inscrito no tópico dht_inteli");
            return true;
        }
        delay(1000);
        if (!verificarWiFi())
            break;
    } while ((millis() - tempoInicial) < 30000L);
    Serial.println("Impossivel estabelecer uma conexao com o broker MQTT!");
    return false;
}

bool verificarMQTT()
{
    if (!verificarWiFi())
        return false;
    if (mqttClient.connected())
        return true;
    Serial.println("Conexao com o broker perdida.");
    mqttClient.disconnect();
    delay(5000);
    return conectarMQTT();
}

void mensagemRecebida(char *topic, byte *payload, unsigned int length)
{
    String mensagem = "";
    Serial.print("Mensagem recebida! Topic: ");
    Serial.print(topic);
    Serial.print(" - Payload (");
    Serial.print(length);
    Serial.print(" bytes): ");
    for (int i = 0; i < length; i++)
    {
        mensagem += (char)payload[i];
    }
    Serial.println(mensagem);
    if (strcmp(topic, "relay_inteli") == 0)
    {
        if (mensagem == "liga")
        {
            Serial.println("LIGA");
            digitalWrite(RELAY_PIN, HIGH);
        }
        if (mensagem == "desliga")
        {
            Serial.println("DESLIGA");
            digitalWrite(RELAY_PIN, LOW);
        }
    }
    Serial.println();
}

void setup()
{
    Serial.begin(115200);
    Serial.println();
    Serial.flush();
    delay(1000);
    Serial.println();
    Serial.flush();
    delay(1000);
    Serial.println("Iniciando...");
    WiFi.mode(WIFI_STA);
    conectarWiFi();
    mqttClient.setBufferSize(256);
    mqttClient.setKeepAlive(60);
    mqttClient.setSocketTimeout(15);
    mqttClient.setCallback(mensagemRecebida);
    mqttClient.setServer(mqttBroker, 1883);
    tempoUltimaMensagem = millis();
    randomSeed(micros());
    conectarMQTT();
    Serial.println("Iniciando o envio...");
    dht.begin();
    pinMode(RELAY_PIN, OUTPUT);
}

void loop()
{
    if (!verificarMQTT())
        return;
    mqttClient.loop();

    float temperatura = dht.readTemperature();
    char payload[16];

    const unsigned long agora = millis();
    if ((agora - tempoUltimaMensagem) >= 5000L)
    {
        tempoUltimaMensagem = agora;
        sprintf(payload, "%.2f", temperatura);
        Serial.print("Enviando temperatura...");
        Serial.println(payload);
        if (mqttClient.publish("dht_inteli", payload)) # dht_inteli é o subscription
        {
            Serial.println("Temperatura enviada!");
        }
        else
        {
            Serial.println("Erro ao enviar a temperatura!");
        }
        Serial.println();
        Serial.println("Aguardando para repetir o processo...");
        Serial.println();
    }
}