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.services;
  
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import jakarta.ws.rs.core.HttpHeaders;
  import jakarta.ws.rs.core.UriInfo;
  
  import org.apache.ambari.server.api.predicate.QueryLexer;
  import org.apache.ambari.server.api.resources.ResourceDefinition;
  import org.apache.ambari.server.api.resources.ResourceInstance;
  
  /**
   * Factory for {@link Request} instances.
   */
  public class RequestFactory {
    /**
     * Create a request instance.
     *
     * @param headers      http headers
     * @param uriInfo      uri information
     * @param requestType  http request type
     * @param resource     associated resource instance
     *
     * @return a new Request instance
     */
    public Request createRequest(HttpHeaders headers, RequestBody body, UriInfo uriInfo, Request.Type requestType,
                                 ResourceInstance resource) {
      switch (requestType) {
        case GET:
          return createGetRequest(headers, body, uriInfo, resource);
        case PUT:
          return createPutRequest(headers, body, uriInfo, resource);
        case DELETE:
          return createDeleteRequest(headers, body, uriInfo, resource);
        case POST:
          return createPostRequest(headers, body, uriInfo, resource);
        default:
          throw new IllegalArgumentException("Invalid request type: " + requestType);
      }
    }
  
    /**
     * Create a GET request.  This will apply any eligible directives supplied in the URI.
     *
     * @param headers  http headers
     * @param uriInfo  uri information
     * @param resource associated resource instance
     * @return new post request
     */
    private Request createGetRequest(HttpHeaders headers, RequestBody body, UriInfo uriInfo, ResourceInstance resource) {
      applyDirectives(Request.Type.GET, body, uriInfo, resource);
      return new GetRequest(headers, body, uriInfo, resource);
    }
  
    /**
     * Create a POST request.  This will either be a standard post request or a query post request.
     * A query post request first applies a query to a collection resource and then creates
     * sub-resources to all matches of the predicate.
     *
     * @param headers   http headers
     * @param uriInfo   uri information
     * @param resource  associated resource instance
     *
     * @return new post request
     */
    private Request createPostRequest(HttpHeaders headers, RequestBody body, UriInfo uriInfo, ResourceInstance resource) {
      boolean batchCreate = !applyDirectives(Request.Type.POST, body, uriInfo, resource);;
  
      return (batchCreate) ?
          new QueryPostRequest(headers, body, uriInfo, resource) :
          new PostRequest(headers, body, uriInfo, resource);
    }
  
    /**
     * Creates a PUT request. It will apply any eligible directives supplied in the URI
     */
    private Request createPutRequest(HttpHeaders headers, RequestBody body, UriInfo uriInfo, ResourceInstance resource) {
      applyDirectives(Request.Type.PUT, body, uriInfo, resource);
      return new PutRequest(headers, body, uriInfo, resource);
    }
  
    /**
     * Creates a DELETE request. It will apply any eligible directives supplied in the URI
     */
    private DeleteRequest createDeleteRequest(HttpHeaders headers, RequestBody body, UriInfo uriInfo, ResourceInstance resource) {
      applyDirectives(Request.Type.DELETE, body, uriInfo, resource);
      return new DeleteRequest(headers, body, uriInfo, resource);
    }
  
    /**
     * Gather query parameters from uri and body query string.
     *
     * @param uriInfo  contains uri info
     * @param body     request body
     *
     * @return map of query parameters or an empty map if no parameters are present
     */
    private Map<String, String> getQueryParameters(UriInfo uriInfo, RequestBody body) {
      Map<String, String> queryParameters = new HashMap<>();
      for (Map.Entry<String, List<String>> entry : uriInfo.getQueryParameters().entrySet()) {
        queryParameters.put(entry.getKey(), entry.getValue().get(0));
      }
  
      String bodyQueryString = body.getQueryString();
      if (bodyQueryString != null && ! bodyQueryString.isEmpty()) {
        String[] toks = bodyQueryString.split("&");
        for (String tok : toks) {
          String[] keyVal = tok.split("=");
          queryParameters.put(keyVal[0], keyVal.length == 2 ? keyVal[1] : "");
        }
      }
      return queryParameters;
    }
  
    /**
     * Applies directives and determines if a query predicate exists or not.
     * <p/>
     * Depending on the request type (POST, PUT, etc...), retrieves the appropriate set of directives:
     * <ul>
     * <li><code>POST</code> - {@link org.apache.ambari.server.api.resources.ResourceDefinition#getCreateDirectives()}</li>
     * <li><code>PUT</code> - {@link org.apache.ambari.server.api.resources.ResourceDefinition#getUpdateDirectives()}</li>
     * </ul>
     * <p/>
     * Note: Only <code>POST</code> and <code>PUT</code> are supported.
     * <p/>
     * Iterates through the query parameters adding those that are known to be directives to the map
     * of request info properties from {@link RequestBody#getRequestInfoProperties()}.
     * <p/>
     * If a query property is found that is not a directive, a query predicate exists and
     * <code>false</code> is returned; else all query parameters are directives, leaving no query predicate,
     * and <code>true</code> is returned.
     *
     * @return true if all the directives are supported; false if at least one directive is not supported
     */
    private boolean applyDirectives(Request.Type requestType, RequestBody body, UriInfo uriInfo, ResourceInstance resource) {
      Map<String, String> queryParameters = getQueryParameters(uriInfo, body);
      queryParameters.remove(QueryLexer.QUERY_DOAS); // KNOX appends a doAs parameter to every request. Ignore this as it's neither a query predicate nor a directive.
      Map<String, String> requestInfoProperties;
      boolean allDirectivesApplicable = true;
      if (!queryParameters.isEmpty()) {
        ResourceDefinition resourceDefinition = resource.getResourceDefinition();
        Collection<String> directives;
        switch (requestType) {
          case PUT:
            directives = resourceDefinition.getUpdateDirectives();
            break;
          case POST:
            directives = resourceDefinition.getCreateDirectives();
            break;
          case GET:
            directives = resourceDefinition.getReadDirectives();
            break;
          case DELETE:
            directives = resourceDefinition.getDeleteDirectives();
            break;
          default:
            // not yet implemented for other types
            return false;
        }
        requestInfoProperties = body.getRequestInfoProperties();
        for (Map.Entry<String, String> entry : queryParameters.entrySet()) {
          if (directives.contains(entry.getKey())) {
            requestInfoProperties.put(entry.getKey(), entry.getValue());
          }
          else {
            allDirectivesApplicable = false;
          }
        }
      }
      return allDirectivesApplicable;
    }
  }
  