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

   1 package net.pterodactylus.sone.notify;
   2
   3 import static com.google.common.base.Preconditions.checkNotNull;
   4
   5 import javax.annotation.Nonnull;
   6 import javax.annotation.Nullable;
   7 import javax.inject.Inject;
   8 import javax.inject.Singleton;
   9
  10 import net.pterodactylus.sone.data.Post;
  11 import net.pterodactylus.sone.data.PostReply;
  12 import net.pterodactylus.sone.data.Sone;
  13
  14 import com.google.common.base.Optional;
  15 import com.google.common.base.Predicate;
  16
  17 /**
  18  * Filter that checks a {@link PostReply} for visibility.
  19  *
  20  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  21  */
  22 @Singleton
  23 public class ReplyVisibilityFilter {
  24
  25         private final PostVisibilityFilter postVisibilityFilter;
  26
  27         @Inject
  28         public ReplyVisibilityFilter(@Nonnull PostVisibilityFilter postVisibilityFilter) {
  29                 this.postVisibilityFilter = postVisibilityFilter;
  30         }
  31
  32         /**
  33          * Checks whether a reply is visible to the given Sone. A reply is not
  34          * considered visible if one of the following statements is true:
  35          * <ul>
  36          * <li>The reply does not have a post.</li>
  37          * <li>The reply’s post {@link PostVisibilityFilter#isPostVisible(Sone, Post) is not visible}.</li>
  38          * <li>The reply’s {@link PostReply#getTime() time} is in the future.</li>
  39          * </ul>
  40          * If none of these statements is true the reply is considered visible.
  41          *
  42          * @param sone
  43          *              The Sone that checks for a post’s visibility (may be
  44          *              {@code null} to skip Sone-specific checks, such as trust)
  45          * @param reply
  46          *              The reply to check for visibility
  47          * @return {@code true} if the reply is considered visible, {@code false}
  48          * otherwise
  49          */
  50         boolean isReplyVisible(@Nullable Sone sone, @Nonnull PostReply reply) {
  51                 checkNotNull(reply, "reply must not be null");
  52                 Optional<Post> post = reply.getPost();
  53                 if (!post.isPresent()) {
  54                         return false;
  55                 }
  56                 if (!postVisibilityFilter.isPostVisible(sone, post.get())) {
  57                         return false;
  58                 }
  59                 return reply.getTime() <= System.currentTimeMillis();
  60         }
  61
  62         @Nonnull
  63         public Predicate<PostReply> isVisible(@Nullable final Sone currentSone) {
  64                 return new Predicate<PostReply>() {
  65                         @Nonnull
  66                         @Override
  67                         public boolean apply(@Nullable PostReply postReply) {
  68                                 return isReplyVisible(currentSone, postReply);
  69                         }
  70                 };
  71         }
  72
  73 }