/*
    * #%L
    * QueryVersionVisitor.java - mongodb-async-driver - Allanbank Consulting, Inc.
    * %%
    * Copyright (C) 2011 - 2014 Allanbank Consulting, Inc.
    * %%
    * Licensed 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.
   * #L%
   */
  package com.allanbank.mongodb.client.message;
  
  import com.allanbank.mongodb.Version;
  import com.allanbank.mongodb.bson.Document;
  import com.allanbank.mongodb.bson.VisitorAdapter;
  import com.allanbank.mongodb.builder.Find;
  import com.allanbank.mongodb.builder.GeospatialOperator;
  import com.allanbank.mongodb.builder.MiscellaneousOperator;
  import com.allanbank.mongodb.client.VersionRange;
  
  /**
   * QueryVersionVisitor provides the ability to inspect a query document for the
   * required server version.
   * 
   * @copyright 2013, Allanbank Consulting, Inc., All Rights Reserved
   */
  public class QueryVersionVisitor extends VisitorAdapter {
  
      /**
       * Helper to returns the required server version to support the query
       * operators.
       * 
       * @param query
       *            The query to inspect.
       * @return The version of the server that is required to support to support
       *         the query. May be {@code null}.
       */
      public static VersionRange version(final Document query) {
          final QueryVersionVisitor visitor = new QueryVersionVisitor();
  
          if (query != null) {
              query.accept(visitor);
          }
  
          return VersionRange.range(visitor.getRequiredServerVersion(),
                  visitor.getMaximumServerVersion());
      }
  
      /**
       * The version of the server that removed the ability to process the visited
       * query.
       */
      private Version myMaximumServerVersion;
  
      /** The required server version to support the query. */
      private Version myRequiredServerVersion;
  
      /**
       * Creates a new QueryVersionVisitor.
       */
      public QueryVersionVisitor() {
          myRequiredServerVersion = null;
      }
  
      /**
       * Returns the version of the server that removed the ability to process the
       * visited query.
       * 
       * @return The version of the server that removed the ability to process the
       *         visited query.
       */
      public Version getMaximumServerVersion() {
          return myMaximumServerVersion;
      }
  
      /**
       * Returns the required server version to support the visited query.
       * 
       * @return The required server version to support the visited query.
       */
      public Version getRequiredServerVersion() {
          return myRequiredServerVersion;
      }
  
      /**
       * <p>
       * Overridden to determine the version of the server required based on the
       * query operators.
       * </p>
       * {@inheritDoc}
      */
     @SuppressWarnings("deprecation")
     @Override
     protected void visitName(final String name) {
         if (GeospatialOperator.GEO_WITHIN.getToken().equals(name)) {
             myRequiredServerVersion = Version.later(myRequiredServerVersion,
                     GeospatialOperator.GEO_WITHIN.getVersion());
         }
         else if (GeospatialOperator.INTERSECT.getToken().equals(name)) {
             myRequiredServerVersion = Version.later(myRequiredServerVersion,
                     GeospatialOperator.INTERSECT.getVersion());
         }
         else if (GeospatialOperator.POLYGON.equals(name)) {
             myRequiredServerVersion = Version.later(myRequiredServerVersion,
                     GeospatialOperator.POLYGON_VERSION);
         }
         else if ("$maxTimeMS".equals(name)) {
             myRequiredServerVersion = Version.later(myRequiredServerVersion,
                     Find.MAX_TIMEOUT_VERSION);
         }
         else if (MiscellaneousOperator.COMMENT.getToken().equals(name)) {
             myRequiredServerVersion = Version.later(myRequiredServerVersion,
                     MiscellaneousOperator.COMMENT.getVersion());
         }
         else if (MiscellaneousOperator.TEXT.getToken().equals(name)) {
             myRequiredServerVersion = Version.later(myRequiredServerVersion,
                     MiscellaneousOperator.TEXT.getVersion());
         }
         else if (GeospatialOperator.UNIQUE_DOCS_MODIFIER.equals(name)) {
             myMaximumServerVersion = Version.earlier(myMaximumServerVersion,
                     GeospatialOperator.UNIQUE_DOCS_REMOVED_VERSION);
         }
     }
 }