// Copyright (C) 2018 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.simplesubmitrules.config;

import com.google.gerrit.entities.Project;
import com.google.gerrit.extensions.restapi.AuthException;
import com.google.gerrit.extensions.restapi.BadRequestException;
import com.google.gerrit.extensions.restapi.Response;
import com.google.gerrit.extensions.restapi.RestModifyView;
import com.google.gerrit.extensions.restapi.RestReadView;
import com.google.gerrit.server.IdentifiedUser;
import com.google.gerrit.server.git.meta.MetaDataUpdate;
import com.google.gerrit.server.permissions.PermissionBackend;
import com.google.gerrit.server.permissions.PermissionBackendException;
import com.google.gerrit.server.permissions.ProjectPermission;
import com.google.gerrit.server.project.ProjectCache;
import com.google.gerrit.server.project.ProjectConfig;
import com.google.gerrit.server.project.ProjectResource;
import com.google.inject.Inject;
import com.google.inject.Provider;
import com.google.inject.Singleton;
import com.googlesource.gerrit.plugins.simplesubmitrules.api.SubmitConfig;
import java.io.IOException;
import org.eclipse.jgit.errors.ConfigInvalidException;

/** REST Endpoint to configure labels and our simple submit rules */
@Singleton
public class ConfigServlet
    implements RestReadView<ProjectResource>, RestModifyView<ProjectResource, SubmitConfig> {
  private final ProjectCache projectCache;
  private final ProjectConfig.Factory projectConfigFactory;
  private final PermissionBackend permissionBackend;
  private final Provider<MetaDataUpdate.User> metaDataUpdateFactory;
  private final ConfigTranslator configTranslator;

  @Inject
  ConfigServlet(
      ProjectCache projectCache,
      PermissionBackend permissionBackend,
      Provider<MetaDataUpdate.User> metaDataUpdateFactory,
      ConfigTranslator configTranslator,
      ProjectConfig.Factory projectConfigFactory) {
    this.projectCache = projectCache;
    this.projectConfigFactory = projectConfigFactory;
    this.permissionBackend = permissionBackend;
    this.metaDataUpdateFactory = metaDataUpdateFactory;
    this.configTranslator = configTranslator;
  }

  @Override
  public Response<SubmitConfig> apply(ProjectResource resource)
      throws AuthException, PermissionBackendException {
    permissionBackend
        .user(resource.getUser())
        .project(resource.getNameKey())
        .check(ProjectPermission.READ_CONFIG);

    return Response.ok(configTranslator.convertFrom(resource.getProjectState()));
  }

  @Override
  public Response<SubmitConfig> apply(ProjectResource resource, SubmitConfig inConfig)
      throws PermissionBackendException, AuthException, BadRequestException, ConfigInvalidException,
          IOException {
    Project.NameKey projectName = resource.getNameKey();
    permissionBackend
        .user(resource.getUser())
        .project(resource.getNameKey())
        .check(ProjectPermission.WRITE_CONFIG);

    IdentifiedUser user = resource.getUser().asIdentifiedUser();
    try (MetaDataUpdate md = metaDataUpdateFactory.get().create(projectName, user)) {
      ProjectConfig projectConfig = projectConfigFactory.read(md);
      configTranslator.applyTo(inConfig, projectConfig);
      projectConfig.commit(md);
      projectCache.evict(projectName);
    }

    return Response.ok(configTranslator.convertFrom(projectCache.checkedGet(projectName)));
  }
}