src/main/java/net/pterodactylus/sone/notify/ListNotificationFilters.java

   1 /*
   2  * Sone - ListNotificationFilters.java - Copyright © 2010 David Roden
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 package net.pterodactylus.sone.notify;
  19
  20 import java.util.ArrayList;
  21 import java.util.Collection;
  22 import java.util.List;
  23
  24 import net.pterodactylus.sone.data.Post;
  25 import net.pterodactylus.sone.data.Reply;
  26 import net.pterodactylus.sone.data.Sone;
  27 import net.pterodactylus.sone.freenet.wot.OwnIdentity;
  28 import net.pterodactylus.sone.freenet.wot.Trust;
  29 import net.pterodactylus.util.notify.Notification;
  30 import net.pterodactylus.util.validation.Validation;
  31
  32 /**
  33  * Filter for {@link ListNotification}s.
  34  *
  35  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  36  */
  37 public class ListNotificationFilters {
  38
  39         /**
  40          * Filters new-post and new-reply notifications in the given list of
  41          * notifications. If {@code currentSone} is <code>null</code>, new-post and
  42          * new-reply notifications are removed completely. If {@code currentSone} is
  43          * not {@code null}, only posts that are posted by a friend Sone or the Sone
  44          * itself, and replies that are replies to posts of friend Sones or the Sone
  45          * itself will be retained in the notifications.
  46          *
  47          * @param notifications
  48          *            The notifications to filter
  49          * @param currentSone
  50          *            The current Sone, or {@code null} if not logged in
  51          * @return The filtered notifications
  52          */
  53         public static List<Notification> filterNotifications(List<Notification> notifications, Sone currentSone) {
  54                 ListNotification<Post> newPostNotification = getNotification(notifications, "new-post-notification", Post.class);
  55                 if (newPostNotification != null) {
  56                         ListNotification<Post> filteredNotification = filterNewPostNotification(newPostNotification, currentSone);
  57                         int notificationIndex = notifications.indexOf(newPostNotification);
  58                         if (filteredNotification == null) {
  59                                 notifications.remove(notificationIndex);
  60                         } else {
  61                                 notifications.set(notificationIndex, filteredNotification);
  62                         }
  63                 }
  64                 ListNotification<Reply> newReplyNotification = getNotification(notifications, "new-replies-notification", Reply.class);
  65                 if (newReplyNotification != null) {
  66                         ListNotification<Reply> filteredNotification = filterNewReplyNotification(newReplyNotification, currentSone);
  67                         int notificationIndex = notifications.indexOf(newReplyNotification);
  68                         if (filteredNotification == null) {
  69                                 notifications.remove(notificationIndex);
  70                         } else {
  71                                 notifications.set(notificationIndex, filteredNotification);
  72                         }
  73                 }
  74                 return notifications;
  75         }
  76
  77         /**
  78          * Filters the new posts of the given notification. If {@code currentSone}
  79          * is {@code null}, {@code null} is returned and the notification is
  80          * subsequently removed. Otherwise only posts that are posted by friend
  81          * Sones of the given Sone are retained; all other posts are removed.
  82          *
  83          * @param newPostNotification
  84          *            The new-post notification
  85          * @param currentSone
  86          *            The current Sone, or {@code null} if not logged in
  87          * @return The filtered new-post notification, or {@code null} if the
  88          *         notification should be removed
  89          */
  90         public static ListNotification<Post> filterNewPostNotification(ListNotification<Post> newPostNotification, Sone currentSone) {
  91                 if (currentSone == null) {
  92                         return null;
  93                 }
  94                 List<Post> newPosts = new ArrayList<Post>();
  95                 for (Post post : newPostNotification.getElements()) {
  96                         if (isPostVisible(currentSone, post)) {
  97                                 newPosts.add(post);
  98                         }
  99                 }
 100                 if (newPosts.isEmpty()) {
 101                         return null;
 102                 }
 103                 if (newPosts.size() == newPostNotification.getElements().size()) {
 104                         return newPostNotification;
 105                 }
 106                 ListNotification<Post> filteredNotification = new ListNotification<Post>(newPostNotification);
 107                 filteredNotification.setElements(newPosts);
 108                 return filteredNotification;
 109         }
 110
 111         /**
 112          * Filters the new replies of the given notification. If {@code currentSone}
 113          * is {@code null}, {@code null} is returned and the notification is
 114          * subsequently removed. Otherwise only replies that are replies to posts
 115          * that are posted by friend Sones of the given Sone are retained; all other
 116          * replies are removed.
 117          *
 118          * @param newReplyNotification
 119          *            The new-reply notification
 120          * @param currentSone
 121          *            The current Sone, or {@code null} if not logged in
 122          * @return The filtered new-reply notification, or {@code null} if the
 123          *         notification should be removed
 124          */
 125         public static ListNotification<Reply> filterNewReplyNotification(ListNotification<Reply> newReplyNotification, Sone currentSone) {
 126                 if (currentSone == null) {
 127                         return null;
 128                 }
 129                 List<Reply> newReplies = new ArrayList<Reply>();
 130                 for (Reply reply : newReplyNotification.getElements()) {
 131                         if (isPostVisible(currentSone, reply.getPost())) {
 132                                 newReplies.add(reply);
 133                         }
 134                 }
 135                 if (newReplies.isEmpty()) {
 136                         return null;
 137                 }
 138                 if (newReplies.size() == newReplyNotification.getElements().size()) {
 139                         return newReplyNotification;
 140                 }
 141                 ListNotification<Reply> filteredNotification = new ListNotification<Reply>(newReplyNotification);
 142                 filteredNotification.setElements(newReplies);
 143                 return filteredNotification;
 144         }
 145
 146         /**
 147          * Finds the notification with the given ID in the list of notifications and
 148          * returns it.
 149          *
 150          * @param <T>
 151          *            The type of the item in the notification
 152          * @param notifications
 153          *            The notification to search
 154          * @param notificationId
 155          *            The ID of the requested notification
 156          * @param notificationElementClass
 157          *            The class of the notification item
 158          * @return The requested notification, or {@code null} if no notification
 159          *         with the given ID could be found
 160          */
 161         @SuppressWarnings("unchecked")
 162         private static <T> ListNotification<T> getNotification(Collection<? extends Notification> notifications, String notificationId, Class<T> notificationElementClass) {
 163                 for (Notification notification : notifications) {
 164                         if (!notificationId.equals(notification.getId())) {
 165                                 continue;
 166                         }
 167                         return (ListNotification<T>) notification;
 168                 }
 169                 return null;
 170         }
 171
 172         /**
 173          * Checks whether a post is visible to the given Sone. A post is not
 174          * considered visible if one of the following statements is true:
 175          * <ul>
 176          * <li>The post does not have a Sone.</li>
 177          * <li>The Sone of the post is not the given Sone, the given Sone does not
 178          * follow the post’s Sone, and the given Sone is not the recipient of the
 179          * post.</li>
 180          * <li>The trust relationship between the two Sones can not be retrieved.</li>
 181          * <li>The given Sone has explicitely assigned negative trust to the post’s
 182          * Sone.</li>
 183          * <li>The given Sone has not explicitely assigned negative trust to the
 184          * post’s Sone but the implicit trust is negative.</li>
 185          * </ul>
 186          * If none of these statements is true the post is considered visible.
 187          *
 188          * @param sone
 189          *            The Sone that checks for a post’s visibility
 190          * @param post
 191          *            The post to check for visibility
 192          * @return {@code true} if the post is considered visible, {@code false}
 193          *         otherwise
 194          */
 195         public static boolean isPostVisible(Sone sone, Post post) {
 196                 Validation.begin().isNotNull("Sone", sone).isNotNull("Post", post).check().isNotNull("Sone’s Identity", sone.getIdentity()).check().isInstanceOf("Sone’s Identity", sone.getIdentity(), OwnIdentity.class).check();
 197                 Sone postSone = post.getSone();
 198                 if (postSone == null) {
 199                         return false;
 200                 }
 201                 Trust trust = postSone.getIdentity().getTrust((OwnIdentity) sone.getIdentity());
 202                 if (trust != null) {
 203                         if ((trust.getExplicit() != null) && (trust.getExplicit() < 0)) {
 204                                 return false;
 205                         }
 206                         if ((trust.getExplicit() == null) && (trust.getImplicit() != null) && (trust.getImplicit() < 0)) {
 207                                 return false;
 208                         }
 209                 } else {
 210                         return false;
 211                 }
 212                 if ((!postSone.equals(sone)) && !sone.hasFriend(postSone.getId()) && !sone.equals(post.getRecipient())) {
 213                         return false;
 214                 }
 215                 return true;
 216         }
 217
 218 }