String input;

bool isPwmPin(int pin) {
  return (pin == 3 || pin == 5 || pin == 6 || pin == 9 || pin == 10 || pin == 11);
}

void setup() {
  Serial.begin(9600);
  while (!Serial) {}  // Wait for serial on some boards
  Serial.println("Ready.");
  Serial.println("Commands:");
  Serial.println("  mode <pin> <input|output>");
  Serial.println("  write <pin> <0|1>");
  Serial.println("  read <pin>");
  Serial.println("  aread <pin>");
  Serial.println("  awrite <pin> <0-255>");
}

void loop() {
  if (Serial.available()) {
    String input = Serial.readStringUntil('\n');
    input.trim();  // Remove whitespace

    if (input.startsWith("mode")) {
      int pin;
      char modeStr[10];
      sscanf(input.c_str(), "mode %d %s", &pin, modeStr);

      if (String(modeStr) == "input") {
        pinMode(pin, INPUT);
        Serial.print("Pin ");
        Serial.print(pin);
        Serial.println(" set as INPUT");

      } else if (String(modeStr) == "output") {
        pinMode(pin, OUTPUT);
        Serial.print("Pin ");
        Serial.print(pin);
        Serial.println(" set as OUTPUT");

      } else {
        Serial.println("Invalid mode. Use 'input' or 'output'");
      }

    } else if (input.startsWith("write")) {
      int pin, val;
      sscanf(input.c_str(), "write %d %d", &pin, &val);
      digitalWrite(pin, val ? HIGH : LOW);
      Serial.print("Pin ");
      Serial.print(pin);
      Serial.print(" set to ");
      Serial.println(val ? "HIGH" : "LOW");

    } else if (input.startsWith("read")) {
      int pin;
      sscanf(input.c_str(), "read %d", &pin);
      int val = digitalRead(pin);
      Serial.print("Pin ");
      Serial.print(pin);
      Serial.print(" value: ");
      Serial.println(val);

    } else if (input.startsWith("aread")) {
      int pin;
      sscanf(input.c_str(), "aread %d", &pin);
      int val = analogRead(pin);
      Serial.print("Analog read pin ");
      Serial.print(pin);
      Serial.print(": ");
      Serial.println(val);

    } else if (input.startsWith("awrite")) {
      int pin, val;
      sscanf(input.c_str(), "awrite %d %d", &pin, &val);
      if (val < 0) val = 0;
      if (val > 255) val = 255;
      if (!isPwmPin(pin)) {
        Serial.print("Warning: Pin ");
        Serial.print(pin);
        Serial.println(" does not support PWM. Analog write will behave like digital write.");
      }
      analogWrite(pin, val);
      Serial.print("Analog write pin ");
      Serial.print(pin);
      Serial.print(" set to ");
      Serial.println(val);

    } else {
      Serial.println("Unknown command");
    }
  }
}