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.cassandra.index.sai.analyzer;
  
  import java.nio.ByteBuffer;
  import java.util.Iterator;
  import java.util.Map;
  import java.util.NoSuchElementException;
  import java.util.stream.Collectors;
  
  import org.apache.cassandra.exceptions.InvalidRequestException;
  import org.apache.cassandra.index.sai.utils.IndexTermType;
  
  public abstract class AbstractAnalyzer implements Iterator<ByteBuffer>
  {
      protected ByteBuffer next = null;
      protected String nextLiteral = null;
  
      /**
       * @return true if index value is transformed, e.g. normalized or lower-cased or tokenized.
       */
      public abstract boolean transformValue();
  
      /**
       * Call when tokenization is finished.  Used by the LuceneAnalyzer.
       */
      public void end()
      {
      }
  
      /**
       * Note: This method does not advance, as we rely on {@link #hasNext()} to buffer the next value.
       *
       * @return the raw value currently buffered by this iterator
       */
      @Override
      public ByteBuffer next()
      {
          if (next == null)
              throw new NoSuchElementException();
          return next;
      }
  
      @Override
      public void remove()
      {
          throw new UnsupportedOperationException();
      }
  
      protected abstract void resetInternal(ByteBuffer input);
  
      public void reset(ByteBuffer input)
      {
          this.next = null;
          this.nextLiteral = null;
  
          resetInternal(input);
      }
  
      public interface AnalyzerFactory
      {
          AbstractAnalyzer create();
  
          default void close()
          {
          }
      }
  
      public static AnalyzerFactory fromOptions(IndexTermType indexTermType, Map<String, String> options)
      {
          if (hasNonTokenizingOptions(options))
          {
              if (indexTermType.isString())
              {
                  // validate options
                  NonTokenizingOptions.fromMap(options);
                  return () -> new NonTokenizingAnalyzer(indexTermType, options);
              }
              else
              {
                  throw new InvalidRequestException("CQL type " + indexTermType.asCQL3Type() + " cannot be analyzed.");
              }
          }
  
          return null;
      }
  
      private static boolean hasNonTokenizingOptions(Map<String, String> options)
      {
          return options.keySet().stream().anyMatch(NonTokenizingOptions::hasOption);
      }
  
      public static Map<String, String> getAnalyzerOptions(Map<String, String> options)
      {
          return options.entrySet().stream()
                        .filter(e -> NonTokenizingOptions.hasOption(e.getKey()))
                        .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
      }
  
  }
  