// Program: Ex5_Array.ino
/*
   Exercise 5 Array, string, and function
   Echo with some modifications
*/

char buf[100] = {0};  // this is an array
char inChar;
bool stringComplete = false;
int i = 0;

// declare the function
// char ConvertString(char);

void setup()
{
  // Initialize serial and wait for port to open
  Serial.begin(115200);
  while (!Serial)
  {
    // Wait for serial port to connect, needed for native USB port only
  }

  // for (int j = 9; j > 0; j--) {
  //   Serial.print('*');
  // }
  // Serial.println();

  // PrintStars(5);
  // PrintStars(22);
}

void loop()
{
  int num;

  while (Serial.available())
  {
    inChar = (char)Serial.read();

    if (inChar == '\n')   // change '\n' to '~' when using Tinkercad
    {
      buf[i++] = inChar;  // last character is newline
      buf[i] = 0;         // string array should be terminated with a zero
      stringComplete = true;
    }
    else
    {
      // some actions after received
      // inChar = ConvertString(inChar);
      buf[i++] = inChar;
    }
  }

  if (stringComplete)
  {
    Serial.print(buf);    // the printing of string will be stopped when zero is reached

    // Serial.print("i = ");
    // Serial.println(i);
    // Serial.print("buf[0] = ");
    // Serial.println(buf[0]);
    // Serial.println(buf[0], DEC);
    // Serial.print("buf[1] = ");
    // Serial.println(buf[1]);
    // Serial.println(buf[1], DEC);
    // Serial.print("buf[2] = ");
    // Serial.println(buf[2]);
    // Serial.println(buf[2], DEC);
    // Serial.print("buf[3] = ");
    // Serial.println(buf[3]);
    // Serial.println(buf[3], DEC);
    // Serial.print("buf[4] = ");
    // Serial.println(buf[4]);
    // Serial.println(buf[4], DEC);
    // Serial.println("----------");

    if ((i == 2) && (isDigit(buf[0]))) {
      num = buf[0] - '0';
      PrintStars(num);
    } else {
      Serial.println("Incorrect input");
      Serial.println();
    }

    stringComplete = false;
    i = 0;
    num = 0;
  }
}

// body of the function
// char ConvertString(char x)
// {
//   if (isUpperCase(x))
//     return (toLowerCase(x));
//   else if (isLowerCase(x))
//     return (toUpperCase(x));
//   else
//     return (x);
// }

// void PrintStars(int n) {
//   for (int j = n; j > 0; j--) {
//     Serial.print('*');
//   }
//   Serial.println();
// }

void PrintStars(int n) {
  for (int j = 0; j < n; j++) {
    Serial.print('*');
  }
  Serial.println();
}