content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF 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
   *
   *     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 org.apache.ambari.server.proxy;
  
  import static jakarta.ws.rs.core.MediaType.APPLICATION_JSON;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.net.HttpURLConnection;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import jakarta.ws.rs.Consumes;
  import jakarta.ws.rs.DELETE;
  import jakarta.ws.rs.GET;
  import jakarta.ws.rs.POST;
  import jakarta.ws.rs.PUT;
  import jakarta.ws.rs.Path;
  import jakarta.ws.rs.core.Context;
  import jakarta.ws.rs.core.HttpHeaders;
  import jakarta.ws.rs.core.MediaType;
  import jakarta.ws.rs.core.MultivaluedMap;
  import jakarta.ws.rs.core.Response;
  import jakarta.ws.rs.core.UriInfo;
  
  import org.apache.ambari.annotations.ApiIgnore;
  import org.apache.ambari.server.controller.internal.URLStreamProvider;
  import org.apache.ambari.server.view.ImpersonatorSettingImpl;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import com.google.gson.Gson;
  
  @Path("/")
  public class ProxyService {
  
    public static final int URL_CONNECT_TIMEOUT = 20000;
    public static final int URL_READ_TIMEOUT = 15000;
    public static final int HTTP_ERROR_RANGE_START = Response.Status.BAD_REQUEST.getStatusCode();
  
    private static final String REQUEST_TYPE_GET = "GET";
    private static final String REQUEST_TYPE_POST = "POST";
    private static final String REQUEST_TYPE_PUT = "PUT";
    private static final String REQUEST_TYPE_DELETE = "DELETE";
    private static final String QUERY_PARAMETER_URL = "url=";
    private static final String AMBARI_PROXY_PREFIX = "AmbariProxy-";
    private static final String ERROR_PROCESSING_URL = "Error occurred during processing URL ";
    private static final String INVALID_PARAM_IN_URL = "Invalid query params found in URL ";
  
    private final static Logger LOG = LoggerFactory.getLogger(ProxyService.class);
  
    @GET @ApiIgnore // until documented
    public Response processGetRequestForwarding(@Context HttpHeaders headers, @Context UriInfo ui) {
      return handleRequest(REQUEST_TYPE_GET, ui, null, headers);
    }
  
    @POST @ApiIgnore // until documented
    @Consumes({MediaType.WILDCARD, MediaType.TEXT_PLAIN, MediaType.TEXT_XML, MediaType.APPLICATION_FORM_URLENCODED, MediaType.APPLICATION_JSON})
    public Response processPostRequestForwarding(InputStream body, @Context HttpHeaders headers, @Context UriInfo ui) {
      return handleRequest(REQUEST_TYPE_POST, ui, body, headers);
    }
  
    @PUT @ApiIgnore // until documented
    @Consumes({MediaType.WILDCARD, MediaType.TEXT_PLAIN, MediaType.TEXT_XML, MediaType.APPLICATION_FORM_URLENCODED, MediaType.APPLICATION_JSON})
    public Response processPutRequestForwarding(InputStream body, @Context HttpHeaders headers, @Context UriInfo ui) {
      return handleRequest(REQUEST_TYPE_PUT, ui, body, headers);
    }
  
    @DELETE @ApiIgnore // until documented
    public Response processDeleteRequestForwarding(@Context HttpHeaders headers, @Context UriInfo ui) {
      return handleRequest(REQUEST_TYPE_DELETE, ui, null, headers);
    }
  
    private Response handleRequest(String requestType, UriInfo ui, InputStream body, HttpHeaders headers) {
      URLStreamProvider urlStreamProvider = new URLStreamProvider(URL_CONNECT_TIMEOUT,
                                                  URL_READ_TIMEOUT, null, null, null);
      String query = ui.getRequestUri().getQuery();
      if (query != null && query.indexOf(QUERY_PARAMETER_URL) != -1) {
        String url = query.replaceFirst(QUERY_PARAMETER_URL, "");
  
        MultivaluedMap<String, String> m = ui.getQueryParameters();
        if (m.containsKey(ImpersonatorSettingImpl.DEFAULT_DO_AS_PARAM)) {              // Case doesn't matter
          LOG.error(INVALID_PARAM_IN_URL + url);
          return Response.status(Response.Status.BAD_REQUEST.getStatusCode()).type(MediaType.TEXT_PLAIN).
              entity(INVALID_PARAM_IN_URL).build();
        }
        
        try {
          HttpURLConnection connection = urlStreamProvider.processURL(url, requestType, body, getHeaderParamsToForward(headers));
          int responseCode = connection.getResponseCode();
          InputStream resultInputStream = null;
          if (responseCode >= HTTP_ERROR_RANGE_START) {
            resultInputStream = connection.getErrorStream();
          } else {
            resultInputStream = connection.getInputStream();
          }
          String contentType = connection.getContentType();
          Response.ResponseBuilder rb = Response.status(responseCode);
          if (contentType.indexOf(APPLICATION_JSON) != -1) {
            rb.entity(new Gson().fromJson(new InputStreamReader(resultInputStream), Map.class));
          } else {
            rb.entity(resultInputStream);
          }
          return rb.type(contentType).build();
        } catch (IOException e) {
          LOG.error(ERROR_PROCESSING_URL + url, e);
          return Response.status(Response.Status.BAD_REQUEST.getStatusCode()).type(MediaType.TEXT_PLAIN).
                 entity(e.getMessage()).build();
        }
      }
      return null;
    }
  
    private Map<String, List<String>> getHeaderParamsToForward(HttpHeaders headers) {
      Map<String, List<String>> headerParamsToForward = new HashMap<>();
      for (String paramName: headers.getRequestHeaders().keySet()) {
        if (paramName.startsWith(AMBARI_PROXY_PREFIX)) {
          headerParamsToForward.put(paramName.replaceAll(AMBARI_PROXY_PREFIX,""), headers.getRequestHeader(paramName));
        }
      }
      return headerParamsToForward;
    }
  
  }
  