Magpie4.java

/*
Aditya Bhatia
10/01/2019
Magpie Lab
*/
import java.lang.Math;
import java.util.Scanner;
import java.util.Random;

public class Magpie4
{
       /**
        * Get a default greeting
        *
        * @return a greeting
        */
       public String getGreeting()
       {
          return "Hello, let's talk.";
       }

       /**
        * Gives a response to a user statement
        *
        * @param statement
        *            the user statement
        * @return a response based on the rules given
        */
       public String getResponse(String statement)
       {
          String response = "";
              if (statement.length() == 0)
              {
                 response = "Say something, please.";
              }
              else if (findKeyword(statement, "no") >= 0)
              {
                     response = "Why so negative?";
              }
              else if (findKeyword(statement, "mother") >= 0
                             || findKeyword(statement, "father") >= 0
                             || findKeyword(statement, "sister") >= 0
                             || findKeyword(statement, "brother") >= 0)
              {
                     response = "Tell me more about your family.";
              }
              else if (statement.indexOf("dog") >= 0 
                     || statement.indexOf("cat") >= 0)
              {
                 response = "Tell me more about your pets.";
              }
              else if (statement.indexOf("Mr. Gaw") >= 0)
              {
                 response = "He sounds like a good teacher.";
              }
              else if (statement.trim().length() == 0)
              {
                 response = "Say something, please.";
              }
              else if (statement.indexOf("school") >= 0)
              {
                 response = "Tell me more about school.";
              }
              else if (statement.indexOf("food") >= 0)
              {
                 response = "I'm hungry";
              }
              else if (statement.indexOf("Earth") >= 0)
              {
                 response = "Mars is superior";
              }
              // Responses which require transformations
              else if (findKeyword(statement, "I want to", 0) >= 0)
              {
                 response = transformIWantToStatement(statement);
              }

              // Responses which require transformations
              else if (findKeyword(statement, "I want", 0) >= 0)
              {
                 response = transformIWantStatement(statement);
              }
              else
              {
                  // Look for a two word (you <something> me)
                  // pattern
                  int psn = findKeyword(statement, "you", 0);
                  int psn1 = findKeyword(statement, "i", 0);
         
                  if (psn >= 0
                      && findKeyword(statement, "me", psn) >= 0)
                  {
                     response = transformYouMeStatement(statement);
                  }
                  else if (psn1 >= 0 && findKeyword(statement, "you", psn1) >=0)
                  {
                     response = transformIYouStatement(statement);
                  }
                  else
                  {
                     response = getRandomResponse();
                  }
               }
               return response;
       }

       /**
        * Search for one word in phrase. The search is not case
        * sensitive. This method will check that the given goal
        * is not a substring of a longer string (so, for
        * example, "I know" does not contain "no").
        *
        * @param statement
        *            the string to search
        * @param goal
        *            the string to search for
        * @param startPos
        *            the character of the string to begin the
        *            search at
        * @return the index of the first occurrence of goal in
        *         statement or -1 if it's not found
        */
       private int findKeyword(String statement, String goal,
                     int startPos)
       {
          String phrase = statement.trim();
              // The only change to incorporate the startPos is in
              // the line below
              int psn = phrase.toLowerCase().indexOf(
                             goal.toLowerCase(), startPos);

              // Refinement--make sure the goal isn't part of a
              // word
              while (psn >= 0)
              {
                     // Find the string of length 1 before and after
                     // the word
                     String before = " ", after = " ";
                     if (psn > 0)
                     {
                             before = phrase.substring(psn - 1, psn)
                                             .toLowerCase();
                     }
                     if (psn + goal.length() < phrase.length())
                     {
                             after = phrase.substring(
                                             psn + goal.length(),
                                             psn + goal.length() + 1)
                                             .toLowerCase();
                     }

         /* determine the values of psn, before, and after at this point */
         //System.out.println(psn + ", " + before + ", " + after);

                     // If before and after aren't letters, we've
                     // found the word
                     if (((before.compareTo("a") < 0) || (before
                                     .compareTo("z") > 0)) // before is not a
                                                                                     // letter
                                     && ((after.compareTo("a") < 0) || (after
                                                     .compareTo("z") > 0)))
                     {
                             return psn;
                     }

                     // The last position didn't work, so let's find
                     // the next, if there is one.
                     psn = phrase.indexOf(goal.toLowerCase(),
                                     psn + 1);

              }

             return -1;
       }
       
       private String transformIWantToStatement(String statement)
   {
         //  Remove the final period, if there is one
         statement = statement.trim();
         String lastChar = statement.substring(statement
                                               .length() - 1);
         if (lastChar.equals("."))
         {
            statement = statement.substring(0, statement
                                               .length() - 1);
         }
         int psn = findKeyword (statement, "I want to", 0);
         String restOfStatement = statement.substring(psn + 9).trim();
         return "What would it mean to " + restOfStatement + "?";
   }
       
       private String transformIWantStatement(String statement)
   {
      //  Remove the final period, if there is one
      statement = statement.trim();
      String lastChar = statement.substring(statement
                                            .length() - 1);
      if (lastChar.equals("."))
      {
         statement = statement.substring(0, statement
                                            .length() - 1);
      }
      int psn = findKeyword (statement, "I want", 0);
      String restOfStatement = statement.substring(psn + 7);
      return "Would you really be happy if you had " + restOfStatement + "?";
   }
       
       private String transformYouMeStatement(String statement)
   {
      //  Remove the final period, if there is one
      statement = statement.trim();
      String lastChar = statement.substring(statement
                                            .length() - 1);
      if (lastChar.equals("."))
      {
         statement = statement.substring(0, statement
                                            .length() - 1);
      }

      int psnOfYou = findKeyword (statement, "you", 0);
      int psnOfMe = findKeyword (statement, "me", psnOfYou + 3);

      String restOfStatement = statement.substring(psnOfYou + 3, psnOfMe).trim();
      return "What makes you think that I " + restOfStatement + " you?";
   }
   
   private String transformIYouStatement(String statement)
   {
      statement = statement.trim();
      String lastChar = statement.substring(statement.length() - 1);
      
      if (lastChar.equals("."))
      {
         statement = statement.substring(0, statement.length() - 1);
      }
      
      int psnOfI = findKeyword(statement, "I", 0);
      int psnOfYou = findKeyword(statement, "You", psnOfI + 1);
      
      String restOfStatement = statement.substring(psnOfI + 1, psnOfYou).trim();
      return "Why do you " + restOfStatement + " me?";
   }

       /**
        * Search for one word in phrase. The search is not case
        * sensitive. This method will check that the given goal
        * is not a substring of a longer string (so, for
        * example, "I know" does not contain "no"). The search
        * begins at the beginning of the string.
        *
        * @param statement
        *            the string to search
        * @param goal
        *            the string to search for
        * @return the index of the first occurrence of goal in
        *         statement or -1 if it's not found
        */
       private int findKeyword(String statement, String goal)
       {
              return findKeyword(statement, goal, 0);
       }

       /**
        * Pick a default response to use if nothing else fits.
        *
        * @return a non-committal string
        */
       private String getRandomResponse()
       {
         Random r = new Random ();
		   return randomResponses [r.nextInt(randomResponses.length)];
       }
       
       private String [] randomResponses = {
         "Interesting, tell me more.",
         "Hmmm.",
         "Do you really think so?",
         "You don't say.",
         "That sounds cool.",
         "Awesome!"
       };

       public static void main(String[] args)
       {
             Magpie4 maggie = new Magpie4();

             String statement = "I like chicken.";
             
             System.out.println("Statement: " + statement);
             System.out.println("Response: " + maggie.getResponse(statement));
       }

}