#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);

#define IN1 18
#define IN2 19
#define IN3 21
#define IN4 22

void setup_wifi() {
  delay(10);
  Serial.println("Connecting to WiFi...");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
  }
  Serial.println("WiFi connected!");
}

void stepForward() {
  digitalWrite(IN1, HIGH); digitalWrite(IN2, LOW); digitalWrite(IN3, HIGH); digitalWrite(IN4, LOW);
  delay(10);
  digitalWrite(IN1, LOW); digitalWrite(IN2, HIGH); digitalWrite(IN3, HIGH); digitalWrite(IN4, LOW);
  delay(10);
  digitalWrite(IN1, LOW); digitalWrite(IN2, HIGH); digitalWrite(IN3, LOW); digitalWrite(IN4, HIGH);
  delay(10);
  digitalWrite(IN1, HIGH); digitalWrite(IN2, LOW); digitalWrite(IN3, LOW); digitalWrite(IN4, HIGH);
  delay(10);
}

void stepBackward() {
  digitalWrite(IN1, HIGH); digitalWrite(IN2, LOW); digitalWrite(IN3, LOW); digitalWrite(IN4, HIGH);
  delay(10);
  digitalWrite(IN1, LOW); digitalWrite(IN2, HIGH); digitalWrite(IN3, LOW); digitalWrite(IN4, HIGH);
  delay(10);
  digitalWrite(IN1, LOW); digitalWrite(IN2, HIGH); digitalWrite(IN3, HIGH); digitalWrite(IN4, LOW);
  delay(10);
  digitalWrite(IN1, HIGH); digitalWrite(IN2, LOW); digitalWrite(IN3, HIGH); digitalWrite(IN4, LOW);
  delay(10);
}

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

  if (command == "FORWARD") {
    Serial.println("Motor Forward");
    for (int i = 0; i < 50; i++) {
      stepForward();
    }
  } else if (command == "BACKWARD") {
    Serial.println("Motor Backward");
    for (int i = 0; i < 50; i++) {
      stepBackward();
    }
  } else if (command == "STOP") {
    Serial.println("Motor Stop");
    digitalWrite(IN1, LOW); digitalWrite(IN2, LOW); digitalWrite(IN3, LOW); digitalWrite(IN4, LOW);
  }
}

void reconnect() {
  while (!client.connected()) {
    Serial.print("Connecting to MQTT...");
    if (client.connect("ESP32Client")) {
      Serial.println("\nMQTT connected!");
      client.subscribe("esp32/motor/control");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

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

  pinMode(IN1, OUTPUT);
  pinMode(IN2, OUTPUT);
  pinMode(IN3, OUTPUT);
  pinMode(IN4, OUTPUT);
}

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