// Copyright (C) 2019 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.forwarder.router;

import static com.googlesource.gerrit.plugins.multisite.forwarder.ForwardedIndexingHandler.Operation.DELETE;
import static com.googlesource.gerrit.plugins.multisite.forwarder.ForwardedIndexingHandler.Operation.INDEX;

import com.google.gerrit.reviewdb.client.Account;
import com.google.inject.Inject;
import com.google.inject.Singleton;
import com.googlesource.gerrit.plugins.multisite.forwarder.ForwardedIndexAccountHandler;
import com.googlesource.gerrit.plugins.multisite.forwarder.ForwardedIndexChangeHandler;
import com.googlesource.gerrit.plugins.multisite.forwarder.ForwardedIndexGroupHandler;
import com.googlesource.gerrit.plugins.multisite.forwarder.ForwardedIndexProjectHandler;
import com.googlesource.gerrit.plugins.multisite.forwarder.ForwardedIndexingHandler;
import com.googlesource.gerrit.plugins.multisite.forwarder.events.AccountIndexEvent;
import com.googlesource.gerrit.plugins.multisite.forwarder.events.ChangeIndexEvent;
import com.googlesource.gerrit.plugins.multisite.forwarder.events.GroupIndexEvent;
import com.googlesource.gerrit.plugins.multisite.forwarder.events.IndexEvent;
import com.googlesource.gerrit.plugins.multisite.forwarder.events.ProjectIndexEvent;
import java.io.IOException;
import java.util.Optional;

@Singleton
public class IndexEventRouter implements ForwardedIndexEventRouter {
  private final ForwardedIndexAccountHandler indexAccountHandler;
  private final ForwardedIndexChangeHandler indexChangeHandler;
  private final ForwardedIndexGroupHandler indexGroupHandler;
  private final ForwardedIndexProjectHandler indexProjectHandler;

  @Inject
  public IndexEventRouter(
      ForwardedIndexAccountHandler indexAccountHandler,
      ForwardedIndexChangeHandler indexChangeHandler,
      ForwardedIndexGroupHandler indexGroupHandler,
      ForwardedIndexProjectHandler indexProjectHandler) {
    this.indexAccountHandler = indexAccountHandler;
    this.indexChangeHandler = indexChangeHandler;
    this.indexGroupHandler = indexGroupHandler;
    this.indexProjectHandler = indexProjectHandler;
  }

  @Override
  public void route(IndexEvent sourceEvent) throws IOException {
    if (sourceEvent instanceof ChangeIndexEvent) {
      ChangeIndexEvent changeIndexEvent = (ChangeIndexEvent) sourceEvent;
      ForwardedIndexingHandler.Operation operation = changeIndexEvent.deleted ? DELETE : INDEX;
      indexChangeHandler.index(
          changeIndexEvent.projectName + "~" + changeIndexEvent.changeId,
          operation,
          Optional.of(changeIndexEvent));
    } else if (sourceEvent instanceof AccountIndexEvent) {
      AccountIndexEvent accountIndexEvent = (AccountIndexEvent) sourceEvent;
      indexAccountHandler.index(
          new Account.Id(accountIndexEvent.accountId), INDEX, Optional.of(accountIndexEvent));
    } else if (sourceEvent instanceof GroupIndexEvent) {
      GroupIndexEvent groupIndexEvent = (GroupIndexEvent) sourceEvent;
      indexGroupHandler.index(groupIndexEvent.groupUUID, INDEX, Optional.of(groupIndexEvent));
    } else if (sourceEvent instanceof ProjectIndexEvent) {
      ProjectIndexEvent projectIndexEvent = (ProjectIndexEvent) sourceEvent;
      indexProjectHandler.index(
          projectIndexEvent.projectName, INDEX, Optional.of(projectIndexEvent));
    } else {
      throw new UnsupportedOperationException(
          String.format("Cannot route event %s", sourceEvent.getType()));
    }
  }
}