package com.atlassian.marketplace.client.impl;
   
   import java.net.URI;
   
   import com.atlassian.marketplace.client.MpacException;
   import com.atlassian.marketplace.client.api.AddonCategories;
   import com.atlassian.marketplace.client.api.ApplicationKey;
   import com.atlassian.marketplace.client.api.Applications;
   import com.atlassian.marketplace.client.model.AddonCategorySummary;
  import com.atlassian.marketplace.client.model.Application;
  
  import com.google.common.collect.ImmutableList;
  
  final class AddonCategoriesImpl implements AddonCategories
  {
      private final ApiHelper apiHelper;
      private final Applications applicationsApi;
  
      AddonCategoriesImpl(ApiHelper apiHelper, Applications applicationsApi)
      {
          this.apiHelper = apiHelper;
          this.applicationsApi = applicationsApi;
          // Note that the per-application category list resource is accessed through a link from the application resource,
          // because we don't have link templates in the API for accessing it directly.
      }
  
      @Override
      public Iterable<AddonCategorySummary> findForApplication(ApplicationKey appKey) throws MpacException
      {
          for (Application a: applicationsApi.getByKey(appKey))
          {
              URI uri = apiHelper.requireLinkUri(a.getLinks(), "addonCategories", Application.class);
              InternalModel.AddonCategories listRep = apiHelper.getEntity(uri, InternalModel.AddonCategories.class);
              return ImmutableList.copyOf(listRep._embedded.categories);
          }
          return ImmutableList.of();
      }
  }