package fr.ippon.tatami.service;
import fr.ippon.tatami.domain.Group;
import fr.ippon.tatami.domain.User;
import fr.ippon.tatami.repository.UserGroupRepository;
import fr.ippon.tatami.service.util.DomainUtil;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Service;
import javax.inject.Inject;
import java.util.*;
import static fr.ippon.tatami.service.util.AnalysisUtil.*;
/**
* Analyses data to find suggestions of users, groups... for the current user.
*/
@Service
public class SuggestionService {
private static final int SAMPLE_SIZE = 20;
private static final int SUB_SAMPLE_SIZE = 100;
private static final int SUGGESTIONS_SIZE = 3;
@Inject
private FriendshipService friendshipService;
@Inject
private UserGroupRepository userGroupRepository;
@Inject
private UserService userService;
@Inject
private GroupService groupService;
/**
* Size of the sample data used to find the suggestions.
*/
@Cacheable("suggest-users-cache")
public Collection<User> suggestUsers(String login) {
Map<String, Integer> userCount = new HashMap<String, Integer>();
List<String> friendIds = friendshipService.getFriendIdsForUser(login);
List<String> sampleFriendIds = reduceCollectionSize(friendIds, SAMPLE_SIZE);
for (String friendId : sampleFriendIds) {
List<String> friendsOfFriend = friendshipService.getFriendIdsForUser(friendId);
friendsOfFriend = reduceCollectionSize(friendsOfFriend, SUB_SAMPLE_SIZE);
for (String friendOfFriend : friendsOfFriend) {
if (!friendIds.contains(friendOfFriend) && !friendOfFriend.equals(login)) {
incrementKeyCounterInMap(userCount, friendOfFriend);
}
}
}
List<String> mostFollowedUsers = findMostUsedKeys(userCount);
List<User> userSuggestions = new ArrayList<User>();
for (String mostFollowedUser : mostFollowedUsers) {
User suggestion = userService.getUserByLogin(mostFollowedUser);
if ( suggestion.getActivated() ){
userSuggestions.add(suggestion);
}
}
if (userSuggestions.size() > SUGGESTIONS_SIZE) {
return userSuggestions.subList(0, SUGGESTIONS_SIZE);
} else {
return userSuggestions;
}
}
@Cacheable("suggest-groups-cache")
public Collection<Group> suggestGroups(String login) {
Map<String, Integer> groupCount = new HashMap<String, Integer>();
List<String> groupIds = userGroupRepository.findGroups(login);
List<String> friendIds = friendshipService.getFriendIdsForUser(login);
friendIds = reduceCollectionSize(friendIds, SAMPLE_SIZE);
for (String friendId : friendIds) {
List<String> groupsOfFriend = userGroupRepository.findGroups(friendId);
for (String groupOfFriend : groupsOfFriend) {
if (!groupIds.contains(groupOfFriend)) {
incrementKeyCounterInMap(groupCount, groupOfFriend);
}
}
}
List<String> mostFollowedGroups = findMostUsedKeys(groupCount);
List<Group> groupSuggestions = new ArrayList<Group>();
String domain = DomainUtil.getDomainFromLogin(login);
for (String mostFollowedGroup : mostFollowedGroups) {
Group suggestion = groupService.getGroupById(domain, mostFollowedGroup);
if (suggestion.isPublicGroup()) { // Only suggest public groups for the moment
groupSuggestions.add(suggestion);
}
}
if (groupSuggestions.size() > SUGGESTIONS_SIZE) {
return groupSuggestions.subList(0, SUGGESTIONS_SIZE);
} else {
return groupSuggestions;
}
}
}