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

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

WiFiClient espClient;
PubSubClient client(espClient);

const int IN1 = 4, IN2 = 16, IN3 = 17, IN4 = 5;

void setup_wifi() {
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) delay(500);
}

void moveStepper(int steps, int direction) {
  for (int i = 0; i < steps; i++) {
    int step = (direction == 1) ? i % 4 : 3 - (i % 4);
    digitalWrite(IN1, step == 0 || step == 3);
    digitalWrite(IN2, step == 1 || step == 2);
    digitalWrite(IN3, step == 0 || step == 1);
    digitalWrite(IN4, step == 2 || step == 3);
    delay(10);
  }
}

void callback(char* topic, byte* payload, unsigned int length) {
  String message = "";
  for (int i = 0; i < length; i++) message += (char)payload[i];

  if (message == "start" || message == "forward") moveStepper(100, 1);
  else if (message == "reverse") moveStepper(100, -1);
  else if (message == "stop") {
    digitalWrite(IN1, LOW); digitalWrite(IN2, LOW);
    digitalWrite(IN3, LOW); digitalWrite(IN4, LOW);
  }
}

void reconnect() {
  while (!client.connected()) {
    if (client.connect("ESP32Motor")) client.subscribe("m/c");
    else delay(5000);
  }
}

void setup() {
  for (int i = IN1; i <= IN4; i++) pinMode(i, OUTPUT);
  Serial.begin(115200);
  setup_wifi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
}

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