package com.atlassian.sal.core.lifecycle;
   
   import com.google.common.base.Function;
   import com.google.common.base.Joiner;
   import com.google.common.collect.Iterables;
   import org.osgi.framework.Bundle;
   import org.osgi.framework.ServiceReference;
   
   import javax.annotation.Nonnull;
  import javax.annotation.Nullable;
  import java.util.Collection;
  
  import static com.atlassian.plugin.osgi.util.OsgiHeaderUtil.getPluginKey;
  
  /**
   * A collection of methods to make lifecycle logging easier
   */
  class LifecycleLog {
      @Nonnull
      static String getPluginKeyFromBundle(@Nullable final Bundle bundle) {
          return (bundle == null) ? "<stale service reference>" : getPluginKey(bundle);
      }
  
      @Nonnull
      static <T> String listPluginKeys(@Nonnull Collection<ServiceReference<T>> services) {
          @SuppressWarnings("unchecked")
          Iterable<String> pluginKeys = Iterables.transform(services, new Function<ServiceReference<T>, String>() {
              @Nullable
              @Override
              public String apply(@Nonnull final ServiceReference<T> service) {
  
                  return getPluginKeyFromBundle(service.getBundle());
              }
          });
  
          return "[" + Joiner.on(", ").join(pluginKeys) + "]";
      }
  }