package facebook;

import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.ArrayList;
import java.util.Iterator;


public class Facebook {
    HashMap<String, Person> people = new HashMap<String, Person>();
    HashMap<String, Group> groups = new HashMap<String, Group>();

    public void addPerson(String code, String name, String surname)
            throws PersonExistsException {
        Person p = new Person(code, name, surname);
        if (people.containsKey(code))
            throw new PersonExistsException();
        people.put(code, p);
    }

    public String getPerson(String code) throws NoSuchCodeException {
        Person p = people.get(code);
        if (p == null)
            throw new NoSuchCodeException();
        return p.toString();
    }

    public void addFriendship(String codePerson1, String codePerson2)
            throws NoSuchCodeException {
        Person p1 = people.get(codePerson1);
        Person p2 = people.get(codePerson2);
        if (p1 == null || p2 == null)
            throw new NoSuchCodeException();
        p1.addFriend(codePerson2);
        p2.addFriend(codePerson1);
    }

    public Collection<String> listOfFriends(String codePerson)
            throws NoSuchCodeException {
        if (people.containsKey(codePerson)) {
            if (people.get(codePerson).getFriends().size() == 0)
                return null;
            else
                return people.get(codePerson).getFriends();
        } else
            throw new NoSuchCodeException();
    }

    public Collection<String> friendsOfFriends(String codePerson)
            throws NoSuchCodeException {
        if (people.size() == 0)
            return null;
        Person p1 = people.get(codePerson);
        if (p1 == null)
            throw new NoSuchCodeException();
        Collection<String> friends = p1.getFriends();
        Iterator<String> it = friends.iterator();
        ArrayList<String> friends2 = new ArrayList<String>();
        while (it.hasNext())
            friends2.addAll(listOfFriends(it.next()));
        if (friends2.size() == 0)
            return null;
        while(friends2.contains(codePerson))
            friends2.remove(codePerson);
        return friends2;
    }

    public Collection<String> friendsOfFriendsNoRepetition(String codePerson)
            throws NoSuchCodeException {
        return new HashSet<String>(friendsOfFriends(codePerson));
    }

    public void addGroup(String groupName) {
        groups.put(groupName, new Group(groupName));
    }

    public Collection<String> listOfGroups() {
        if (groups.size() == 0)
            return null;
        return groups.keySet();
    }

    public void addPersonToGroup(String codePerson, String groupName) {
        Group g = groups.get(groupName);
        Person p = people.get(codePerson);
        if (p == null || g == null)
            return;
        g.addPerson(codePerson);
        p.addGroup(groupName);
    }

    public Collection<String> listOfPeopleInGroup(String groupName) {
        Group g = groups.get(groupName);
        if (g.getMembers().size() == 0)
            return null;
        return g.getMembers();
    }

    public String personWithLargestNumberOfFriends() {
        Collection<Person> pp = people.values();
        Iterator<Person> it = pp.iterator();
        int max = 0;
        String pmax = null;
        while (it.hasNext()) {
            Person p = it.next();
            int s = p.getFriends().size();
            if (s > max) {
                max = s;
                pmax = p.getCode();
            }
        }
        return pmax;
    }

    public String personWithMostFriendsOfFriends() {
        Collection<Person> pp = people.values();
        Iterator<Person> it = pp.iterator();
        int max = 0;
        String pmax = null;
        while (it.hasNext()) {
            Person p = it.next();
            int s=0;
            try {
                if (friendsOfFriends(p.getCode())!=null)
                    s = friendsOfFriendsNoRepetition(p.getCode()).size();
            } catch (NoSuchCodeException e) {
                return null;
            }
            if (s > max) {
                max = s;
                pmax = p.getCode();
            }
        }
        return pmax;
    }

    public String largestGroup() {
        Collection<Group> pp = groups.values();
        Iterator<Group> it = pp.iterator();
        int max = 0;
        String gmax = null;
        while (it.hasNext()) {
            Group p = it.next();
            int s = p.getMembers().size();
            if (s > max) {
                max = s;
                gmax = p.getName();
            }
        }
        return gmax;
    }

    public String personInLargestNumberOfGroups() {
        Collection<Person> pp = people.values();
        Iterator<Person> it = pp.iterator();
        int max = 0;
        String pmax = null;
        while (it.hasNext()) {
            Person p = it.next();
            int s = p.getGroups().size();
            if (s > max) {
                max = s;
                pmax = p.getCode();
            }
        }
        return pmax;
    }
}