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.cql3.restrictions;
  
  import java.nio.ByteBuffer;
  
  import org.apache.cassandra.cql3.Operator;
  import org.apache.cassandra.utils.ByteBufferUtil;
  
  import static org.apache.cassandra.cql3.statements.RequestValidations.invalidRequest;
  
  public final class LikePattern
  {
      public enum Kind
      {
          PREFIX(Operator.LIKE_PREFIX),
          SUFFIX(Operator.LIKE_SUFFIX),
          CONTAINS(Operator.LIKE_CONTAINS),
          MATCHES(Operator.LIKE_MATCHES);
  
          private final Operator operator;
  
          Kind(Operator operator)
          {
              this.operator = operator;
          }
  
          public Operator operator()
          {
              return operator;
          }
      }
  
      private static final ByteBuffer WILDCARD = ByteBufferUtil.bytes("%");
  
      private final Kind kind;
  
      private final ByteBuffer value;
  
      private LikePattern(Kind kind, ByteBuffer value)
      {
          this.kind = kind;
          this.value = value;
      }
  
      public Kind kind()
      {
          return kind;
      }
  
      public ByteBuffer value()
      {
          return value;
      }
  
      /**
       * As the specific subtype of LIKE (LIKE_PREFIX, LIKE_SUFFIX, LIKE_CONTAINS, LIKE_MATCHES) can only be
       * determined by examining the value, which in turn can only be known after binding, all LIKE restrictions
       * are initially created with the generic LIKE operator. This function takes the bound value, trims the
       * wildcard '%' chars from it and returns a tuple of the inferred operator subtype and the final value
       * @param value the bound value for the LIKE operation
       * @return  Pair containing the inferred LIKE subtype and the value with wildcards removed
       */
      public static LikePattern parse(ByteBuffer value)
      {
          Kind kind;
          int beginIndex = value.position();
          int endIndex = value.limit() - 1;
          if (ByteBufferUtil.endsWith(value, WILDCARD))
          {
              if (ByteBufferUtil.startsWith(value, WILDCARD))
              {
                  kind = Kind.CONTAINS;
                  beginIndex =+ 1;
              }
              else
              {
                  kind = Kind.PREFIX;
              }
          }
          else if (ByteBufferUtil.startsWith(value, WILDCARD))
          {
              kind = Kind.SUFFIX;
              beginIndex += 1;
              endIndex += 1;
          }
          else
          {
              kind = Kind.MATCHES;
              endIndex += 1;
          }
  
          if (endIndex == 0 || beginIndex == endIndex)
              throw invalidRequest("LIKE value can't be empty.");
  
          ByteBuffer newValue = value.duplicate();
          newValue.position(beginIndex);
          newValue.limit(endIndex);
          return new LikePattern(kind, newValue);
      }
  }
  