package beer.persistence;

import beer.helper.Utils;
import beer.model.Comment;
import beer.model.Organization;
import beer.model.Stats;
import beer.model.User;
import beer.model.forum.Category;
import beer.model.forum.Forum;
import beer.model.forum.Reply;
import beer.model.forum.Topic;
import beer.model.message.has.Folder;
import beer.model.user.has.Box;
import beer.model.user.has.Group;
import beer.model.user.has.GroupMembership;
import beer.model.user.has.Theme;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import org.hibernate.Criteria;
import org.hibernate.criterion.Expression;
import org.hibernate.criterion.Order;
import org.hibernate.criterion.Restrictions;

/**
 *
 * @author Ulisses
 */
public class Query extends Base implements Serializable {

    private Query() {
    }
    private static Query uniqueInstance;
    public static final long ALL_FORUMS = 0;

    public static Query getInstance() {
        synchronized (Query.class) {
            if (uniqueInstance == null) {
                uniqueInstance = new Query();
            }
            return uniqueInstance;
        }
    }

    /**
     * Gets the 5 more recent changes posted on the Changelog Topic by the Webmaster.
     * @return
     */
    public List getChangelog() {
        try {
            org.hibernate.Query query = session.createQuery(
                    "FROM Reply " +
                    "WHERE cd_topic = 10 AND " +
                    "cd_reply_user = 1 " +
                    "ORDER BY cd_reply DESC");
            query.setMaxResults(5);
            List changelogs = query.list();

            return changelogs;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets the 10 latest News.
     * "News" are any Topics with a "News" section value.
     * @return The latest 10 News Topics.
     */
    public List getNews() {
        try {
            org.hibernate.Query query = session.createQuery(
                    "FROM Topic " +
                    "WHERE nm_topic_section = 'News' " +
                    "ORDER BY cd_topic DESC");
            query.setMaxResults(10);

            return query.list();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets all the Forums within a Category
     * @param category
     * @return
     */
    public List getForums(Category category) {
        try {
            org.hibernate.Query query = session.createQuery(
                    "FROM Forum " +
                    "WHERE cd_forum_category =:CATEGORY " +
                    "ORDER BY dt_forum_created DESC");
            query.setLong("CATEGORY", category.getId());
            List forums = query.list();

            return forums;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets the latest replied Topics.
     * @param maxResults The number of results you want.
     * @return Topics List.
     */
    public List getRecentActiveTopics(int maxResults) {
        try {
            org.hibernate.Query query = session.createQuery(
                    "FROM Topic " +
                    "ORDER BY " +
                    "lastReply.dateReplied DESC, " +
                    "dateCreated DESC");
            query.setMaxResults(maxResults);

            return query.list();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets the latest created Topics.
     * @param maxResults The number of results you want.
     * @param forumId If you want the topics from a specific Forum, you can pass it's id,
     * otherwise you need to pass in a Query.ALL_FORUMS value.
     * @return A Topic List.
     */
    public List getRecentCreatedTopics(int maxResults, long forumId) {
        try {
            org.hibernate.Query query;

            if (forumId == ALL_FORUMS) {
                query = session.createQuery(
                        "FROM Topic " +
                        "ORDER BY id DESC");

            } else {
                query = session.createQuery(
                        "FROM Topic " +
                        "WHERE forum =:ID " +
                        "ORDER BY id DESC");

                query.setLong("ID", forumId);
            }
            query.setMaxResults(maxResults);

            return query.list();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets the Topics with the highest view count.
     * @param maxResults Number of results you want.
     * @return Topic List.
     */
    public List getMostViewedTopics(int maxResults) {
        try {
            org.hibernate.Query query = session.createQuery(
                    "FROM Topic " +
                    "ORDER BY vl_topic_times_viewed DESC");
            query.setMaxResults(maxResults);

            return query.list();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets the most viewed <code>Topic</code>.
     * You can pass in a specific <code>Forum</code> id, or pass a <code>Query.ALL_FORUMS</code> value.
     * @param forumId The <code>Forum</code> id, or Query.ALL_FORUMS.
     * @return A <code>Topic</code>.
     */
    public Topic getMostViewedTopic(long forumId) {
        try {
            org.hibernate.Query query;
            if (forumId == ALL_FORUMS) {
                query = session.createQuery(
                        "FROM Topic " +
                        "ORDER BY vl_topic_times_viewed DESC");
            } else {
                query = session.createQuery(
                        "FROM Topic " +
                        "WHERE cd_topic_forum =:ID " +
                        "ORDER BY vl_topic_times_viewed DESC");
                query.setLong("ID", forumId);
            }
            query.setMaxResults(1);
            Topic topic = (Topic) query.uniqueResult();

            return topic;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets all replies in a <code>Topic</code>.
     * @param userTopic The <code>Topic</code>.
     * @return <code>Reply</code> <code>List</code>.
     */
    public List getReplies(Topic userTopic) {
        try {
            org.hibernate.Query query = session.createQuery(
                    "FROM Reply " +
                    "WHERE cd_topic =:TOPIC");
            query.setLong("TOPIC", userTopic.getId());
            List replies = query.list();

            return replies;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets specific <code>Stats</code>.
     * @param statsName The name of the stat you want.
     * @return A <code>Stats</code> object.
     */
    public Stats getStats(String statsName) {
        try {
            Stats stats = (Stats) session.createQuery(
                    "FROM Stats " +
                    "WHERE nm_stats='" + statsName + "'").uniqueResult();

            return stats;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets a <code>User</code> from a <code>String</code> that
     * represents an E-Mail from a dvlCUBE User.
     * @param mail A <code>String</code> containing and E-Mail address
     * @return
     */
    public User getExistingEmail(String mail) {
        try {
            User user = (User) session.createQuery(
                    "FROM User " +
                    "WHERE cd_user_mail = '" + mail + "'").uniqueResult();

            return user;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets all Topics in the specified Forum ordered by the date of the last reply on that topic.
     * @param forumId Forum Id
     * @return List containing all the Topics in the specified Forum
     */
    public List getTopics(long forumId) {
        try {
            org.hibernate.Query query = session.createQuery(
                    "FROM Topic " +
                    "WHERE forum =:ID " +
                    "ORDER BY " +
                    "lastReply.dateReplied DESC, " +
                    "dateCreated DESC");
            query.setLong("ID", forumId);

            /*Criteria criteria = session.createCriteria(Topic.class);
            criteria.add(Restrictions.eq("forum", forumId));
            criteria.addOrder(Order.desc("lastReply"));
            criteria.addOrder(Order.desc("dateCreated"));*/

            List topics = query.list();
            //List topics = criteria.list();
            return topics;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets the most recent reply made on the Topic provided.
     * @param topicId The id of Topic desired.
     * @return Returns the most recent reply found. If there's no Reply in the Topic, it returns a default placeholder Reply.
     */
    public Reply getLastReply(long topicId, boolean dummy) {
        try {
            org.hibernate.Query query = session.createQuery(
                    "FROM Reply " +
                    "WHERE cd_topic =:ID " +
                    "ORDER BY dt_replied DESC");
            query.setLong("ID", topicId);
            query.setMaxResults(1);
            Reply reply = (Reply) query.uniqueResult();

            if (dummy == true && reply == null) {
                reply = (Reply) get("beer.model.forum.Reply@1");
            }

            return reply;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets the last Reply made in a Topic.
     * @param topicId Id of the Topic.
     * @return The Reply.
     */
    public Reply getLastReply(long topicId) {
        try {
            org.hibernate.Query query = session.createQuery(
                    "FROM Reply " +
                    "WHERE cd_topic =:ID " +
                    "ORDER BY dt_replied DESC");
            query.setLong("ID", topicId);
            query.setMaxResults(1);
            Reply reply = (Reply) query.uniqueResult();

            return reply;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    @Deprecated
    public Topic getLastTopic() {
        try {
            org.hibernate.Query query = session.createQuery(
                    "FROM Topic " +
                    "WHERE cd_topic_forum =:ID " +
                    "ORDER BY dt_topic_created DESC");
            query.setMaxResults(1);
            Topic topic = (Topic) query.uniqueResult();

            return topic;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets all Users whose name or mail address matches the String[] item.
     * @param nameOrAddress An array containing names or e-mails from dvlCUBE Users.
     * @return A <code>User List</code>.
     */
    public List getUsers(String[] nameOrAddress) {
        try {
            List<User> users = new ArrayList<User>();
            for (int i = 0; i < nameOrAddress.length; i++) {
                User user = (User) session.createQuery(
                        "FROM User " +
                        "WHERE " +
                        "cd_user_mail = '" + nameOrAddress[i] + "' OR " +
                        "nm_user = '" + nameOrAddress[i] + "'").uniqueResult();
                if (user != null) {
                    users.add(user);
                }
            }
            if (users.size() > 0) {
                return users;
            } else {
                return null;
            }
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Searches for a single <code>User</code> with the given name.
     * @param nickname
     * @return
     */
    public User getExistingNickname(String nickname) {
        try {
            User user = (User) session.createQuery(
                    "FROM User " +
                    "WHERE nm_user = '" + nickname + "'").uniqueResult();

            return user;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets a single <code>User</code> with the given e-mail and password.
     * @param login A <code>String</code> array containing the e-mail [0] and password [1].
     * @return A <code>User</code> object.
     */
    public User getRegisteredUser(String[] login) {
        try {
            User user = (User) session.createQuery(
                    "FROM User " +
                    "WHERE " +
                    "cd_user_mail = '" + login[0] + "' AND " +
                    "cd_user_password = '" + login[1] + "'").uniqueResult();

            return user;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets an <code>Organization</code> object that matches the given name <code>String</code>.
     * @param organizationName
     * @return
     */
    public Organization getOrganization(String organizationName) {
        try {
            Organization organization = (Organization) session.createQuery(
                    "FROM Organization " +
                    "WHERE nm_organization = '" + organizationName + "'").uniqueResult();

            return organization;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets a single file from a specific <code>User</code>.
     * The user must own the file.
     * @param id The file id;
     * @param userId The <code>User</code> id.
     * @return A <code>Box</code> object.
     */
    public Box getFileFromBox(long id, long userId) {
        try {
            Box box = (Box) session.createQuery(
                    "FROM Box " +
                    "WHERE " +
                    "cd_file = " + id + " AND " +
                    "cd_file_user = " + userId).uniqueResult();

            return box;

        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * get all boxes from a user.
     * @param user
     * @return
     */
    public List getBoxes(User user) {
        try {
            org.hibernate.Query query = session.createQuery(
                    "SELECT DISTINCT(folder) " +
                    "FROM Box " +
                    "WHERE user = " + user.getId() +
                    " ORDER BY dateCreated DESC");
            List boxes = query.list();

            return boxes;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets all shared boxes from a <code>User</code>.
     * @param user
     * @return
     */
    public List getSharedBoxes(long user) {
        try {
            org.hibernate.Query query = session.createQuery(
                    "SELECT DISTINCT(folder) " +
                    "FROM Box " +
                    "WHERE user = :USER " +
                    "AND publicFile = true" +
                    " ORDER BY dateCreated DESC");
            query.setLong("USER", user);
            List boxes = query.list();

            return boxes;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Get all files from a private folder.
     * @param user
     * @param folder
     * @return
     */
    public List getFilesFrom(User user, String folder) {
        try {
            List files = session.createQuery(
                    "FROM Box " +
                    "WHERE " +
                    "user = " + user.getId() + "AND " +
                    "folder = '" + folder + "' " +
                    "ORDER BY dateCreated DESC").list();
            return files;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets all files in a shared folder.
     * Not constrained to a specific <code>User</code>.
     * @param folder <code>Box</code> name.
     * @return All files in a shared folder.
     */
    public List getPublicFilesFrom(String folder) {
        try {
            List files = session.createQuery(
                    "FROM Box " +
                    "WHERE " +
                    "nm_file_folder = '" + folder + "' " +
                    "AND ic_public = 1 " +
                    "ORDER BY dt_file_created DESC").list();
            return files;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets all files in a shared <code>User</code> folder.
     * @param user The <code>User</code> you want to browse files from.
     * @param folder <code>Box</code> name.
     * @return All files in a shared folder.
     */
    public List getPublicFilesFrom(long user) {
        try {
            Criteria criteria = session.createCriteria(Box.class);
            criteria.add(Expression.eq("user", user)).add(Expression.eq("publicFile", true)).addOrder(Order.desc("dateCreated"));
            return criteria.list();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets all files in a shared <code>User</code> folder.
     * @param user The <code>User</code> you want to browse files from.
     * @param folder <code>Box</code> name.
     * @return All files in a shared folder.
     */
    public List getPublicFilesFrom(User user, String folder) {
        try {
            Criteria criteria = session.createCriteria(Box.class);
            criteria.add(Expression.eq("user", user)).add(Expression.eq("folder", folder)).add(Expression.eq("publicFile", true)).addOrder(Order.desc("dateCreated"));
            return criteria.list();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * populate a list of images a user has previously uploaded to a box.
     * @param user
     * @return
     */
    public List getBoxImages(User user) {
        try {
            org.hibernate.Query query = session.createQuery(
                    "SELECT name " +
                    "FROM Box " +
                    "WHERE " +
                    "name = 'default-user.png' OR " +
                    "(type like 'image%' AND " +
                    "user = " + user.getId() + ")" +
                    " ORDER BY name");
            List pictures = query.list();

            return pictures;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets the default site <code>Theme</code>
     * @return
     */
    public Theme getDefaultTheme() {
        try {
            Theme defaultTheme = (Theme) session.createQuery(
                    "FROM Theme " +
                    "WHERE id = 2").uniqueResult();

            return defaultTheme;

        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    public User getUserById(long id) {
        try {
            User user = (User) session.createQuery(
                    "FROM User " +
                    "WHERE id = " + id).uniqueResult();
            return user;

        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Creates a list that can be divided into n pages.
     * @param listStart
     * @param listMaxResults
     * @return
     */
    public List getUsers(int listStart, int listMaxResults) {
        try {
            Criteria criteria = session.createCriteria(User.class).addOrder(Order.desc("totalPosts"));
            criteria.setFirstResult(listStart);
            criteria.setMaxResults(listMaxResults);

            List user = criteria.list();
            return user;

        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Creates a list that can be divided into n pages.
     * @param listStart The List will start from this row;
     * @param listMaxResults The list will return this (max) ammount of results;
     * @param order The desired <code>Order</code> object.
     * @return A <code>User List</code>.
     */
    public List getUsers(int listStart, int listMaxResults, Order order) {
        try {
            Criteria criteria = session.createCriteria(User.class).addOrder(order);
            criteria.setFirstResult(listStart);
            criteria.setMaxResults(listMaxResults);

            List user = criteria.list();
            return user;

        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * This method takes a String and return all beer.model.User's who met the search String.
     * @param search Search string (name attribute).
     * @return Returns a List of users that met the search String.
     */
    public List getUsers(String search) {
        try {
            Criteria criteria = session.createCriteria(User.class);
            criteria.add(Expression.like("name", "%" + search + "%"));

            List users = criteria.list();
            return users;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * A lighter version for getting existing names in a given Entity. Intended for use in an ajax application.
     * @param param The String to search for.
     * @param entity The Entity.
     * @return A List containing only the String names found.
     */
    public List getNames(String param, String entity) {
        try {
            org.hibernate.Query query = session.createQuery(
                    "SELECT name " +
                    "FROM " + entity +
                    " WHERE name like :PARAM");
            query.setString("PARAM", "%" + param + "%");

            return query.list();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * This heavier version of <code>getNames()</code> gives more freedom, since it returns the whole Object.
     * Constraint: the Entity must have a <code>name</code> or <code>subject</code> property in its bean.
     * (Currently not working).
     * @param param The String to search for.
     * @param entity The Entity.
     * @return A List that can be cast to whatever type the Entity is.
     */
    public List getNamesLike(String param, String entity) {
        try {
            org.hibernate.Query query;

            if (entity.equals("Forum")) {
                query = session.createQuery(
                        "FROM Forum " +
                        "WHERE name LIKE :PARAM");
            } else if (entity.equals("Topic")) {
                query = session.createQuery(
                        "FROM Topic " +
                        "WHERE subject LIKE :PARAM");
            } else if (entity.equals("Mail")) {
                query = session.createQuery(
                        "FROM User " +
                        "WHERE " +
                        "name LIKE :PARAM OR " +
                        "mail LIKE :PARAM");
            } else {
                return null;
            }
            query.setString("PARAM", "%" + param + "%");

            return query.list();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * This heavier version of <code>getNames()</code> gives more freedom, since it returns the whole Object.
     * This overloaded version doesn't return results that are already in the collection provided.
     * @param param The String to search for.
     * @param entity The Entity.
     * @param collection A <code>String Array</code> containing the values you don't want
     * this query to return again.
     * @return A List that can be cast according to the Entity name.
     * Returns only the first 35 results.
     */
    public List getNamesLike(String param, String entity, String[] collectionArray) {
        try {
            String collection = Utils.arrayToString(collectionArray);
            org.hibernate.Query query;
            if (entity.equals("Mail")) {
                query = session.createQuery(
                        "FROM User " +
                        "WHERE " +
                        "name LIKE :PARAM OR " +
                        "mail LIKE :PARAM " +
                        "AND mail NOT IN(:COLLECTION)");
            } else {
                return null;
            }
            query.setString("PARAM", "%" + param + "%");
            query.setString("COLLECTION", collection);
            query.setMaxResults(35);

            return query.list();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Tentativa usando criteria. Currently not fully working.
     * @param param
     * @param entity
     * @param collectionArray
     * @return
     */
    public List getNamesLike2(String param, String entity, String[] collectionArray) {
        try {
            Criteria criteria = session.createCriteria(User.class);
            criteria.add(Expression.ilike("name", "%" + param + "%")).add(Expression.ilike("mail", "%" + param + "%")).add(Restrictions.not(Expression.in("mail", collectionArray)));
            return criteria.list();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Searches for content in Replies or Topics.
     * @param param
     * @param entity Can be Reply or Topic
     * @return
     */
    public List getContentLike(String param, String entity) {
        try {
            org.hibernate.Query query = session.createQuery(
                    "FROM " + entity +
                    " WHERE content like :PARAM");
            query.setString("PARAM", "%" + param + "%");

            return query.list();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    public Comment getComment(long commentId, long userId) {
        try {
            Comment comment = (Comment) session.createQuery(
                    "FROM Comment " +
                    "WHERE cd_comment = " + commentId +
                    " AND cd_user = " + userId).uniqueResult();

            return comment;

        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }

    }

    public List getMessages(String folder, User user) {
        try {
            org.hibernate.Query query = session.createQuery(
                    "FROM Message " +
                    "WHERE cd_message_user =:USER AND " +
                    "nm_message_folder =:FOLDER " +
                    "ORDER BY dt_message_sent DESC");
            query.setLong("USER", user.getId());
            query.setString("FOLDER", folder);

            List messages = query.list();

            return messages;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    public Long getNewMessages(String folder, long userId) {
        try {
            Long newMessages = (Long) session.createQuery(
                    "SELECT COUNT(read) " +
                    "FROM Message " +
                    "WHERE " +
                    "cd_message_user = " + userId +
                    " AND " +
                    "nm_message_folder = '" + folder + "' " +
                    "AND " +
                    "ic_message_read < 1").uniqueResult();

            return newMessages;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    @Deprecated
    public List getMessages2(String folder, User user) {
        try {
            org.hibernate.Query query = session.createQuery(
                    "SELECT " +
                    "cd_message, " +
                    "cd_message_user, " +
                    "nm_message_content, " +
                    "cd_message_sender, " +
                    "cd_message_recipient, " +
                    "nm_message_subject, " +
                    "cd_message_folder, " +
                    "ic_message_read, " +
                    "dt_message_sent " +
                    "FROM Message m, Folder f " +
                    "WHERE " +
                    "m.cd_message_user = f.cd_folder_user " +
                    "AND " +
                    "f.nm_folder = '" + folder + "' " +
                    "AND " +
                    "m.cd_message_user = " + user.getId());

            List messages = query.list();
            return messages;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    @Deprecated
    public Folder getFolder(Folder userFolder) {
        try {
            Folder folder = (Folder) session.createQuery(
                    "FROM Folder " +
                    "WHERE nm_folder = '" + userFolder.getName() + "' " +
                    "AND cd_folder_user = " + userFolder.getUser().getId()).uniqueResult();

            return folder;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    public List getMailFolders(User user) {
        try {
            org.hibernate.Query query = session.createQuery(
                    "SELECT DISTINCT(folder) " +
                    "FROM Message " +
                    "WHERE " +
                    "cd_message_user = " + user.getId() +
                    " ORDER BY nm_message_folder ASC");

            List folders = query.list();
            return folders;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    public Long getMailFolderSize(String folder, long userId) {
        try {
            Long size = (Long) session.createQuery(
                    "SELECT COUNT(id) " +
                    "FROM Message " +
                    "WHERE " +
                    "nm_message_folder = '" + folder + "' " +
                    "AND " +
                    "cd_message_user = " + userId).uniqueResult();
            return size;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets all the Forums created by the given User.
     * @param user The User object.
     * @return All the Forums that User has created.
     */
    public List getUserForums(User user) {
        try {
            Criteria criteria = session.createCriteria(Forum.class);
            criteria.add(Restrictions.eq("author", user));

            return criteria.list();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    public List getUserContacts(User user) {
        try {
            List<User> contacts = new ArrayList<User>();
            org.hibernate.Query queryRecipients = session.createQuery(
                    "SELECT DISTINCT(recipient) " +
                    "FROM Message " +
                    "WHERE cd_message_user = " + user.getId());

            org.hibernate.Query querySenders = session.createQuery(
                    "SELECT DISTINCT(sender) " +
                    "FROM Message " +
                    "WHERE cd_message_user = " + user.getId());

            List<User> contactsA = queryRecipients.list();
            List<User> contactsB = querySenders.list();
            contacts.addAll(contactsA);
            for (int i = 0; i < contactsB.size(); i++) {
                if (!(contactsA.contains(contactsB.get(i)))) {
                    contacts.add(contactsB.get(i));
                }
            }
            return contacts;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets the number of unread messages from a specific user Inbox.
     * @param user The user.
     * @return A Long with the number of unread messages.
     */
    public Long getNewMessages(long userId) {
        try {
            Long newMessages = (Long) session.createQuery(
                    "SELECT COUNT(id) " +
                    "FROM Message " +
                    "WHERE " +
                    "user.id =:ID AND " +
                    "folder = 'Inbox' AND " +
                    "read = false").setLong("ID", userId).uniqueResult();

            return newMessages;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets a <code>Group</code> with the given owner and name.
     * @param user The owner of the <code>Group</code>;
     * @param name The name of the <code>Group</code>.
     * @return The <code>Group</code>, if any.
     */
    public Group getGroup(User user, String name) {
        try {
            Criteria criteria = session.createCriteria(Group.class);
            criteria.add(Restrictions.eq("owner", user));
            criteria.add(Restrictions.eq("name", name));

            if (criteria != null) {
                return (Group) criteria.uniqueResult();
            } else {
                return null;
            }
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets all <code>Group</code>s created by the given <code>User</code>.
     * @param user The <code>User</code>.
     * @return <code>Group List</code>.
     */
    public List getGroups(User user) {
        try {
            Criteria criteria = session.createCriteria(Group.class);
            criteria.add(Restrictions.eq("owner", user));
            return criteria.list();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets all <code>GroupMemberships</code> in the given <code>Group</code>.
     * @param group The <code>Group</code>.
     * @return <code>GroupMembership List</code>.
     */
    public List getMemberships(Group group) {
        try {
            Criteria criteria = session.createCriteria(GroupMembership.class);
            criteria.add(Restrictions.eq("group", group));
            return criteria.list();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets all <code>GroupMemberships</code> in the given <code>Group</code>
     * that has the given <code>User</code> as a member.
     * @param group The <code>Group</code>.
     * @param user The <code>User</code> member.
     * @return <code>GroupMembership List</code>.
     */
    public List getMembership(Group group, User member) {
        try {
            Criteria criteria = session.createCriteria(GroupMembership.class);
            criteria.add(Restrictions.eq("group", group));
            criteria.add(Restrictions.eq("member", member));
            if (criteria.list().size() > 0) {
                return criteria.list();
            } else {
                return null;
            }
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Checks if a <code>GroupMembership</code> already exists to avoid duplicates.
     * Deprecated. Use getMembership(Group, User) instead.
     * @param group The <code>Group</code>;
     * @param user The <code>User</code>.
     * @return Whether there's a membership beetween these two objects.
     */
    @Deprecated
    public boolean membershipExists(Group group, User user) {
        try {
            org.hibernate.Query query = session.createQuery(
                    "FROM GroupMembership " +
                    "WHERE " +
                    "cd_group = :GROUPID AND " +
                    "cd_member = :USERID");
            query.setLong("GROUPID", group.getId());
            query.setLong("USERID", user.getId());

            if (query.list() == null) {
                return false;
            } else {
                return true;
            }
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    /**
     * Gets the latest <code>Topic</code>s from the Tips section.
     * @param maxResults The number of <code>Topic</code>s to be returned.
     * @return A <code>Topic List</code>.
     */
    public List<Topic> getTips(int maxResults) {
        try {
            Criteria criteria = session.createCriteria(Topic.class);
            criteria.add(Restrictions.eq("section", "Tips"));
            criteria.setMaxResults(maxResults);

            return criteria.list();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }
}