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.api;
  
  import java.io.IOException;
  import java.io.StringWriter;
  import java.io.Writer;
  import java.util.LinkedHashMap;
  import java.util.Map;
  import java.util.UUID;
  
  import jakarta.servlet.RequestDispatcher;
  import jakarta.servlet.http.HttpServletRequest;
  import jakarta.servlet.http.HttpServletResponse;
  
  import org.apache.ambari.server.security.authentication.jwt.JwtAuthenticationProperties;
  import org.apache.ambari.server.security.authentication.jwt.JwtAuthenticationPropertiesProvider;
  import org.apache.commons.lang.StringUtils;
  import org.apache.commons.lang3.exception.ExceptionUtils;
  import org.eclipse.jetty.http.HttpStatus;
  import org.eclipse.jetty.http.MimeTypes;
  import org.eclipse.jetty.server.HttpChannel;
  import org.eclipse.jetty.server.HttpConnection;
  import org.eclipse.jetty.server.Request;
  import org.eclipse.jetty.server.handler.ErrorHandler;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import com.google.gson.Gson;
  import com.google.inject.Inject;
  import com.google.inject.name.Named;
  
  /**
   * Custom error handler for Jetty to return response as JSON instead of stub http page
   */
  public class AmbariErrorHandler extends ErrorHandler {
    private static final Logger LOG = LoggerFactory.getLogger(AmbariErrorHandler.class);
  
    private final Gson gson;
  
    private JwtAuthenticationPropertiesProvider jwtAuthenticationPropertiesProvider;
  
    @Inject
    public AmbariErrorHandler(@Named("prettyGson") Gson prettyGson, JwtAuthenticationPropertiesProvider jwtAuthenticationPropertiesProvider) {
      this.gson = prettyGson;
      this.jwtAuthenticationPropertiesProvider = jwtAuthenticationPropertiesProvider;
    }
  
    @Override
    public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException {
      HttpChannel connection = HttpConnection.getCurrentConnection().getHttpChannel();
      connection.getRequest().setHandled(true);
  
      response.setContentType(MimeTypes.Type.TEXT_PLAIN.asString());
  
      Map<String, Object> errorMap = new LinkedHashMap<>();
      int code = connection.getResponse().getStatus();
      errorMap.put("status", code);
      String message = connection.getResponse().getReason();
      if (message == null) {
        message = HttpStatus.getMessage(code);
      }
      errorMap.put("message", message);
  
  
      Throwable th = (Throwable) request.getAttribute(RequestDispatcher.ERROR_EXCEPTION);
      if (th != null) {
        if (code == org.apache.http.HttpStatus.SC_INTERNAL_SERVER_ERROR) {
          UUID requestId = UUID.randomUUID();
          message = "Internal server error, please refer the exception by " + requestId + " in the server log file";
          errorMap.put("message", message);
          LOG.error(message + ", requestURI: " + request.getRequestURI(), th);
        }
  
        if (this.isShowStacks()) {
          StringWriter writer = new StringWriter();
          writeErrorPageStacks(request, writer);
          errorMap.put("reason:", writer.toString());
        }
      }
  
      if ((code == HttpServletResponse.SC_FORBIDDEN) || (code == HttpServletResponse.SC_UNAUTHORIZED)) {
        //if SSO is configured we should provide info about it in case of access error
        JwtAuthenticationProperties jwtProperties = jwtAuthenticationPropertiesProvider.get();
        if ((jwtProperties != null) && jwtProperties.isEnabledForAmbari()) {
          String providerUrl = jwtProperties.getAuthenticationProviderUrl();
          String originalUrl = jwtProperties.getOriginalUrlQueryParam();
  
          if (StringUtils.isEmpty(providerUrl)) {
            LOG.warn("The SSO provider URL is not available, forwarding to the SSO provider is not possible");
          } else if (StringUtils.isEmpty(originalUrl)) {
            LOG.warn("The original URL parameter name is not available, forwarding to the SSO provider is not possible");
          } else {
            errorMap.put("jwtProviderUrl", String.format("%s?%s=", providerUrl, originalUrl));
          }
        }
      }
  
      gson.toJson(errorMap, response.getWriter());
    }
  
    @Override
    protected void writeErrorPageStacks(HttpServletRequest request, Writer writer)
      throws IOException {
      Throwable th = (Throwable) request.getAttribute(RequestDispatcher.ERROR_EXCEPTION);
  
      while (th != null) {
        writer.write("Caused by:\n");
        write(writer, ExceptionUtils.getStackTrace(th));
        writer.write("\n");
        th = th.getCause();
      }
    }
  }
  