/*
    * Copyright 2018 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.admin.auth;
  
  import static java.util.Objects.requireNonNull;
  
  import com.linecorp.armeria.common.HttpRequest;
  import com.linecorp.armeria.common.HttpResponse;
  import com.linecorp.armeria.server.HttpService;
  import com.linecorp.armeria.server.ServiceRequestContext;
  import com.linecorp.armeria.server.ServiceRequestContextWrapper;
  import com.linecorp.armeria.server.file.FileService;
  
  public final class OrElseDefaultHttpFileService implements HttpService {
  
      private final HttpService delegate;
  
      public OrElseDefaultHttpFileService(FileService fileService, String defaultPath) {
          requireNonNull(fileService, "fileService");
          requireNonNull(defaultPath, "defaultPath");
          // Always return '/index.html' if there is no entry on the requested path, in order to route
          // the request by 'react-router'.
          delegate = fileService.orElse(
                  (ctx, req) -> fileService.serve(new DefaultHtmlServiceRequestContext(ctx, defaultPath), req));
      }
  
      @Override
      public HttpResponse serve(ServiceRequestContext ctx, HttpRequest req) throws Exception {
          return delegate.serve(ctx, req);
      }
  
      // TODO(hyangtack) Use a better HTTP file service later which serves only one file.
      private static final class DefaultHtmlServiceRequestContext extends ServiceRequestContextWrapper {
  
          private final String defaultPath;
  
          private DefaultHtmlServiceRequestContext(ServiceRequestContext delegate, String defaultPath) {
              super(delegate);
              this.defaultPath = defaultPath;
          }
  
          @Override
          public String decodedMappedPath() {
              return defaultPath;
          }
      }
  }