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

const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "broker.hivemq.com";

const int relayPinLights = 2;
const int relayPinFans = 22;

WiFiClient espClient;
PubSubClient client(espClient);
unsigned long lastMsg = 0;
#define MSG_BUFFER_SIZE  (50)

void setup_wifi() {

  delay(10);
  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("Message arrived [");
  Serial.print(topic);
  Serial.print("] ");
  for (int i = 0; i < length; i++) {
    Serial.print((char)payload[i]);
  }
  Serial.println();

  if (strcmp(topic, "iot/lights") == 0) {
    if ((boolean)payload[0] == true) {
      digitalWrite(relayPinLights, HIGH);
    } else if ((boolean)payload[0] == false){
      digitalWrite(relayPinLights, LOW);
    }
  } else if (strcmp(topic, "iot/fans") == 0) {
    if ((boolean)payload[0] == true) {
      digitalWrite(relayPinFans, HIGH); 
    } else if ((boolean)payload[0] == false) {
      digitalWrite(relayPinFans, LOW); 
    }
  }
}

void reconnect() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    String clientId = "ESP8266Client-";
    clientId += String(random(0xffff), HEX);
    if (client.connect(clientId.c_str())) {
      Serial.println("Connected");
      client.publish("iot/mqtt", "iot");
      client.subscribe("iot/mqtt");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

void setup() {
  pinMode(relayPinLights, OUTPUT);
  pinMode(relayPinFans, OUTPUT);
  Serial.begin(115200);
  setup_wifi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);

  digitalWrite(relayPinLights,LOW);
  digitalWrite(relayPinFans,LOW);
}

void loop() {

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

  unsigned long now = millis();
  if (now - lastMsg > 2000) {
    lastMsg = now;
    client.subscribe("iot/lights");
    client.subscribe("iot/fans");
  }
}