package com.atlassian.streams.refapp;
   
   import com.atlassian.streams.api.ActivityObjectType;
   import com.atlassian.streams.api.ActivityVerb;
   import com.atlassian.streams.api.common.Pair;
   import com.atlassian.streams.spi.ActivityOptions;
   import com.atlassian.streams.spi.StreamsFilterOption;
   import com.atlassian.streams.spi.StreamsFilterOptionProvider;
   import com.atlassian.streams.spi.StreamsI18nResolver;
  import com.google.common.base.Function;
  import com.google.common.collect.ImmutableList;
  
  import static com.atlassian.streams.api.ActivityObjectTypes.article;
  import static com.atlassian.streams.api.ActivityObjectTypes.comment;
  import static com.atlassian.streams.api.ActivityObjectTypes.file;
  import static com.atlassian.streams.api.ActivityObjectTypes.status;
  import static com.atlassian.streams.api.ActivityVerbs.like;
  import static com.atlassian.streams.api.ActivityVerbs.post;
  import static com.atlassian.streams.api.ActivityVerbs.update;
  import static com.atlassian.streams.api.common.Pair.pair;
  import static com.google.common.base.Preconditions.checkNotNull;
  import static com.google.common.collect.ImmutableSet.of;
  import static com.google.common.collect.Iterables.transform;
  
  public class RefappFilterOptionProvider implements StreamsFilterOptionProvider {
      private static final Iterable<Pair<ActivityObjectType, ActivityVerb>> SUPPORT_ACTIVITIES = of(
              pair(article(), post()),
              pair(article(), update()),
              pair(article(), like()),
              pair(comment(), post()),
              pair(comment(), update()),
              pair(comment(), like()),
              pair(file(), post()),
              pair(file(), update()),
              pair(status(), update())
      );
  
      private final Function<Pair<ActivityObjectType, ActivityVerb>, ActivityOption> toActivityOption;
  
      public RefappFilterOptionProvider(final StreamsI18nResolver i18nResolver) {
          this.toActivityOption = ActivityOptions.toActivityOption(checkNotNull(i18nResolver, "i18nResolver"), "streams.filter.refapp");
      }
  
      @Override
      public Iterable<StreamsFilterOption> getFilterOptions() {
          // Standard filters is provided by the framework, we don't create specific filter options.
          return ImmutableList.of();
      }
  
      @Override
      public Iterable<StreamsFilterOptionProvider.ActivityOption> getActivities() {
          return transform(SUPPORT_ACTIVITIES, toActivityOption);
      }
  }