// SEHR höflich Bot, wer nur gute Wörter sagen kann


String data;
bool received = false;

#define VARIANTS 3
#define SIZE 2


void setup()
{
  Serial.begin(9600);
  Serial.println("Hi! Write /help to find out all the commands !");
}

void loop()
{
  while(Serial.available() > 0)
  {
    data += (char)Serial.read();
    received = true;
    delay(2);
  }
  if(received)
  {
    data.remove(data.length() - 1);
    if(data.length())
    {
      Serial.println("User: " + data);
      data.trim();
      data.toLowerCase();
      Serial.println("Bot: " + answer(data));
      data = "";
    }
    received = false;
  }
}

String answer(String message)
{
  //const unsigned int SIZE = 2, VARIANTS = 3;
  String commands[SIZE] = {"hello", "goodbye"};
  String answers[SIZE][VARIANTS] = {
    {"Hello!", "Hey!", "Hi!"},
    {"Goodbye!", "Bye!", "See you later!"}
  };
  for(unsigned int i = 0; i < SIZE; i++)
    if(message == commands[i])
      return answers[i][random(VARIANTS)];
  if(message == "/help")
  {
    if(SIZE > 0)
    {
      String ans = "\nSecrete phrases: ";
      for(unsigned int i = 0; i < SIZE; i++)
        ans += "\n" + String(i+1) + ". \"" + commands[i] + "\";";
      ans += "\nChoose one and send me one messege";
      return ans;
    }
  }
  return "Sorry, but I can't answer this message.";
}