// Demonstrates some fun analysis on Facebook data.
// To use, first download the RestFB library from http://restfb.com/
// In Eclipse, right click on your project and go to Properties
// Then, access Java Build Path > Libraries and click on the "Add External Jar" button
// Select the library's jar file.
// You'll also need a temporary access token from Facebook (see below)
import java.util.*;
import com.restfb.*;
import com.restfb.types.*;

public class FBPlay {
   public static void main(String[] args) {
      // get your own temporary access token from
      // http://developers.facebook.com/tools/explorer/
      String token = "";
      FacebookClient facebookClient = new DefaultFacebookClient(token);

      // quick test
      User zuck = facebookClient.fetchObject("zuck", User.class);
      System.out.println(zuck.getName());

      List<User> myFriends = facebookClient.fetchConnection("me/friends",
            User.class, Parameter.with("fields", "first_name, gender"))
            .getData();

      System.out.println("Total friends: " + myFriends.size());

      // map first names to their frequencies
      Map<String, Integer> nameCounts = new TreeMap<String, Integer>();

      for (User friend : myFriends) {
         String name = friend.getFirstName();
         if (!nameCounts.containsKey(name)) {
            nameCounts.put(friend.getFirstName(), 0);
         }
         nameCounts.put(name, nameCounts.get(name) + 1);
      }
      System.out.println(nameCounts);

      // map frequencies to sets of names (essentially, flip the key and value)
      Map<Integer, Set<String>> popularities = new TreeMap<Integer, Set<String>>();
      for (String name : nameCounts.keySet()) {
         int times = nameCounts.get(name);

         if (!popularities.containsKey(times)) {
            popularities.put(times, new TreeSet<String>());
         }
         popularities.get(times).add(name);
      }
      System.out.println(popularities);
   }
}