def processInput(userInput):
  pass

def main():
  pass
  
main()

def main():
  # Print a simple message to let the user know what the chatbot can talk about
  print("Welcome to Cow Facts! I can talk to you about cows!\n")
  print("Ask me a question or type quit\n")

  userInput = ""

  # If the user doesn't say 'quit' then we should keep going
  while userInput != "quit":
      # Ask the user for a question about the subject
      userInput = input("Whats your question? ").lower()

      # IF the users hasn't quit
      if userInput != "quit":
          # Process their input and print the response
          response = processInput(userInput)
          print(response)

  # The user has quit so we can say goodbye
  print("It was good talking to you! Bye!")

# Takes in the users question and returns a response
def processInput(userInput):

    # List of responses to provide to the user
    responses = {
        "what": "Cattle — colloquially cows — are the most common type of large domesticated ungulates.",
        "use": "Cattle are commonly raised as livestock for meat (beef or veal, see beef cattle), for milk (see dairy cattle), and for hides, which are used to make leather.",
        "used": "Cattle are commonly raised as livestock for meat (beef or veal, see beef cattle), for milk (see dairy cattle), and for hides, which are used to make leather."
    }

    # List of prompts to provide the user if the answer is unclear
    prompts = {
        "what": "What are cows?",
        "use": "What use is there for cows?",
        "used": "What are cows used for?"
    }

    # Filter out white space from the front of the users message and remove all symbols
    userInput = re.sub(r'[^\w\s]','', userInput)

    # Split the users inputs into individual words for key matching
    words = userInput.split(" ")

    # Initial list of keys to match
    matchingKeys = []

    # Loop throught each word in the users input
    for word in words:
        # If the word matches a word in the responses keys
        if word in responses.keys():
            # Add the users word to the matching keys list
            matchingKeys.append(word)

    # If matching keys is empty then no key was found and the chatbot doesn't know about it
    if len(matchingKeys) == 0:
        return "I don't know that"
    # If there is only one matching key then we can just return that response
    elif len(matchingKeys) <= 1:
        return responses[matchingKeys[0]]
    else:
        # There are more than one matching keys so we need clarification
        print("I am not quite sure about what you mean. Did you mean: ")
        index = 1
        # Loop through each key we found
        for key in matchingKeys:
            # Provide a number for selection and the prompt for that key we created above.
            print(str(index) + ": " + prompts[key])
            # Increase the index of the prompts for selection
            index += 1
        # Setup for finding a valid key
        valid = False
        # While we don't have a valid key we want to continue asking for a proper key
        while not valid:
            # Get the number from the user
            selected = int(input("#: "))
            # Check if the number is one of the possible key index
            if selected <= len(matchingKeys) and selected > 0:
                # If it is then we are good to return our response
                valid = True
            else:
                # Otherwise reprompt the user
                print("Please enter one of the above")
        # Return the selected keys response
        return responses[matchingKeys[selected - 1]]