package org.apache.lucene.codecs.lucene3x;

/**
 * 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.
 */

import java.io.IOException;

import org.apache.lucene.codecs.TermVectorsReader;
import org.apache.lucene.codecs.TermVectorsWriter;
import org.apache.lucene.index.FieldInfos;
import org.apache.lucene.index.SegmentInfo;
import org.apache.lucene.index.SegmentReadState;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.IOContext;
import org.apache.lucene.util.LuceneTestCase;

class PreFlexRWTermVectorsFormat extends Lucene3xTermVectorsFormat {

  @Override
  public TermVectorsWriter vectorsWriter(Directory directory, String segment, IOContext context) throws IOException {
    return new PreFlexRWTermVectorsWriter(directory, segment, context);
  }

  @Override
  public TermVectorsReader vectorsReader(SegmentReadState state) throws IOException {
    return new Lucene3xTermVectorsReader(state.dir, state.segmentInfo, state.fieldInfos, state.context) {
      @Override
      protected boolean sortTermsByUnicode() {
        // We carefully peek into stack track above us: if
        // we are part of a "merge", we must sort by UTF16:
        boolean unicodeSortOrder = true;

        StackTraceElement[] trace = new Exception().getStackTrace();
        for (int i = 0; i < trace.length; i++) {
          //System.out.println(trace[i].getClassName());
          if ("merge".equals(trace[i].getMethodName())) {
            unicodeSortOrder = false;
            if (LuceneTestCase.VERBOSE) {
              System.out.println("NOTE: PreFlexRW codec: forcing legacy UTF16 vector term sort order");
            }
            break;
          }
        }

        return unicodeSortOrder;
      }
    };
  }
}