// Copyright (C) 2016 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package com.googlesource.gerrit.plugins.events;

import com.google.common.base.Supplier;
import com.google.gerrit.entities.EntitiesAdapterFactory;
import com.google.gerrit.entities.Project;
import com.google.gerrit.extensions.registration.DynamicSet;
import com.google.gerrit.server.events.Event;
import com.google.gerrit.server.events.EventListener;
import com.google.gerrit.server.events.ProjectNameKeyAdapter;
import com.google.gerrit.server.events.SupplierSerializer;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.inject.Inject;
import com.google.inject.Singleton;
import java.io.IOException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@Singleton
public class CoreListener implements EventListener {
  private static Logger log = LoggerFactory.getLogger(CoreListener.class);

  protected static final Gson gson =
      new GsonBuilder()
          .registerTypeAdapter(Supplier.class, new SupplierSerializer())
          .registerTypeAdapter(Project.NameKey.class, new ProjectNameKeyAdapter())
          .registerTypeAdapterFactory(EntitiesAdapterFactory.create())
          .create();
  protected final DynamicSet<StreamEventListener> listeners;
  protected final EventStore store;

  @Inject
  protected CoreListener(EventStore store, DynamicSet<StreamEventListener> listeners) {
    this.store = store;
    this.listeners = listeners;
  }

  @Override
  public void onEvent(Event event) {
    try {
      store.add(gson.toJson(event));
    } catch (IOException e) {
      log.error("Cannot add event to event store", e);
    }
    for (StreamEventListener l : listeners) {
      l.onStreamEventUpdate();
    }
  }
}