/*
    * Copyright 2017 LINE Corporation
    *
    * LINE Corporation licenses this file to you 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:
    *
    *   https://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.linecorp.centraldogma.server.internal.api.converter;
  
  import static com.google.common.base.Preconditions.checkArgument;
  import static com.google.common.base.Strings.isNullOrEmpty;
  import static java.util.Objects.requireNonNull;
  
  import java.lang.reflect.ParameterizedType;
  
  import javax.annotation.Nullable;
  
  import com.linecorp.armeria.common.AggregatedHttpRequest;
  import com.linecorp.armeria.common.HttpStatus;
  import com.linecorp.armeria.server.ServiceRequestContext;
  import com.linecorp.armeria.server.annotation.RequestConverterFunction;
  import com.linecorp.centraldogma.common.Author;
  import com.linecorp.centraldogma.server.internal.admin.auth.AuthUtil;
  import com.linecorp.centraldogma.server.internal.api.HttpApiUtil;
  import com.linecorp.centraldogma.server.internal.storage.project.ProjectApiManager;
  import com.linecorp.centraldogma.server.metadata.User;
  import com.linecorp.centraldogma.server.storage.project.Project;
  import com.linecorp.centraldogma.server.storage.repository.Repository;
  
  /**
   * A default {@link RequestConverterFunction} of HTTP API.
   */
  public final class HttpApiRequestConverter implements RequestConverterFunction {
  
      private final ProjectApiManager projectApiManager;
  
      public HttpApiRequestConverter(ProjectApiManager projectApiManager) {
          this.projectApiManager = requireNonNull(projectApiManager, "projectApiManager");
      }
  
      @Override
      public Object convertRequest(
              ServiceRequestContext ctx, AggregatedHttpRequest request, Class<?> expectedResultType,
              @Nullable ParameterizedType expectedParameterizedResultType) throws Exception {
  
          if (expectedResultType == Project.class) {
              final String projectName = ctx.pathParam("projectName");
              checkArgument(!isNullOrEmpty(projectName),
                            "project name should not be null or empty.");
  
              // ProjectNotFoundException would be thrown if there is no project.
              return projectApiManager.getProject(projectName);
          }
  
          if (expectedResultType == Repository.class) {
              final String projectName = ctx.pathParam("projectName");
              checkArgument(!isNullOrEmpty(projectName),
                            "project name should not be null or empty.");
              final String repositoryName = ctx.pathParam("repoName");
              checkArgument(!isNullOrEmpty(repositoryName),
                            "repository name should not be null or empty.");
  
              if (Project.REPO_DOGMA.equals(repositoryName) &&
                  !AuthUtil.currentUser(ctx).isAdmin()) {
                  return HttpApiUtil.throwResponse(
                          ctx, HttpStatus.FORBIDDEN,
                          "Repository '%s/%s' can be accessed only by an administrator.",
                          projectName, Project.REPO_DOGMA);
              }
              // RepositoryNotFoundException would be thrown if there is no project or no repository.
              return projectApiManager.getProject(projectName).repos().get(repositoryName);
          }
  
          if (expectedResultType == Author.class) {
              return AuthUtil.currentAuthor(ctx);
          }
  
          if (expectedResultType == User.class) {
              return AuthUtil.currentUser(ctx);
          }
  
          return RequestConverterFunction.fallthrough();
      }
  }