// Program: Ex5_Q1_3_v2.ino
// Check of goodString using an all-in-one approach
/*
   Exercise 5 Q1
   Extend the program of Ex5_Array to read an integer
   (with at most 2 digits) from the Serial Monitor and
   print out a group of stars that is equal to the integer value.
   The star should be arranged in rows of ten.
*/

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

// declare the function
//char ConvertString(char);
void PrintStars(int);

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
  }
  Serial.println("Input a number:");
}

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

    if (inChar == '\n')   // change '\n' to '~' when using Tinkercad (Change 1 of 2)
    {
      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)
  {
    goodString = true;

    /*
      if ((i < 2) || (i > 3))
      {
      goodString = false;
      }
      else
      {
      //for (int j = 0; buf[j] != '\n'; j++)  // change '\n' to '~' when using Tinkercad (Change 2 of 2)
      for (int j = 0; j < i - 1; j++)
      {
        if (!isdigit(buf[j]))
          goodString = false;
      }
      }
    */

    if (((i == 2) && isdigit(buf[0])) || ((i == 3) && isdigit(buf[0]) && (isdigit(buf[1])))) {
      goodString = true;
    } else {
      goodString = false;
    }

    if (goodString)
    {
      if (i == 2)
      {
        Num = buf[0] - '0';
      }
      else
      {
        Num = (buf[0] - '0') * 10 + (buf[1] - '0');
      }
      Serial.println(Num);
      PrintStars(Num);
    }
    else
    {
      Serial.print(buf);
      Serial.println("Incorrect input");
    }

    //Serial.print(buf);      // the printing of string will be stopped when zero is reached
    stringComplete = false;
    i = 0;
    Serial.println();
    Serial.println("Input a number:");
  }
}

// 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 x)
{
  for (int i = 1; i <= x; i++)
  {
    Serial.print("*");
    if (!(i % 10))
      Serial.println();
  }
  if (x % 10)
    Serial.println();
  return;
}