// Copyright (C) 2015 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.multisite.event;

import com.gerritforge.gerrit.globalrefdb.validation.ProjectsFilter;
import com.google.gerrit.extensions.registration.DynamicSet;
import com.google.gerrit.server.config.GerritInstanceId;
import com.google.gerrit.server.events.Event;
import com.google.gerrit.server.events.EventListener;
import com.google.gerrit.server.events.ProjectEvent;
import com.google.inject.Inject;
import com.googlesource.gerrit.plugins.multisite.forwarder.StreamEventForwarder;
import java.util.concurrent.Executor;

class EventHandler implements EventListener {
  private final Executor executor;
  private final DynamicSet<StreamEventForwarder> forwarders;
  private final ProjectsFilter projectsFilter;
  private final String nodeInstanceId;

  @Inject
  EventHandler(
      DynamicSet<StreamEventForwarder> forwarders,
      @EventExecutor Executor executor,
      ProjectsFilter projectsFilter,
      @GerritInstanceId String nodeInstanceId) {
    this.forwarders = forwarders;
    this.executor = executor;
    this.projectsFilter = projectsFilter;
    this.nodeInstanceId = nodeInstanceId;
  }

  @Override
  public void onEvent(Event event) {

    if (nodeInstanceId.equals(event.instanceId) && event instanceof ProjectEvent) {
      if (projectsFilter.matches(event)) {
        executor.execute(new EventTask(event));
      }
    }
  }

  class EventTask implements Runnable {
    private final Event event;

    EventTask(Event event) {
      this.event = event;
    }

    @Override
    public void run() {
      forwarders.forEach(f -> f.send(event));
    }

    @Override
    public String toString() {
      return String.format("Send event '%s' to target instance", event.type);
    }
  }
}