package org.apache.lucene.search.spell;

/**
 * Copyright 2002-2005 The Apache Software Foundation
 *
 * 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.
 */

import org.apache.lucene.index.IndexReader;

import java.util.Iterator;

import org.apache.lucene.index.TermEnum;
import org.apache.lucene.index.Term;

import java.io.*;

/**
 * Lucene Dictionary
 *
 * @author Nicolas Maisonneuve
 */
public class LuceneDictionary implements Dictionary {
  IndexReader reader;
  String field;

  public LuceneDictionary(IndexReader reader, String field) {
    this.reader = reader;
    this.field = field;
  }

  public final Iterator getWordsIterator() {
    return new LuceneIterator();
  }


  final class LuceneIterator implements Iterator {
    private TermEnum termEnum;
    private Term actualTerm;
    private boolean has_next_called;

    public LuceneIterator() {
      try {
        termEnum = reader.terms(new Term(field, ""));
      } catch (IOException ex) {
        ex.printStackTrace();
      }
    }


    public Object next() {
      if (!has_next_called) {
        hasNext();
      }
      has_next_called = false;
      return (actualTerm != null) ? actualTerm.text() : null;
    }


    public boolean hasNext() {
      has_next_called = true;
      try {
        // if there is still words
        if (!termEnum.next()) {
          actualTerm = null;
          return false;
        }
        //  if the next word are in the field
        actualTerm = termEnum.term();
        String fieldt = actualTerm.field();
        if (fieldt != field) {
          actualTerm = null;
          return false;
        }
        return true;
      } catch (IOException ex) {
        ex.printStackTrace();
        return false;
      }
    }

    public void remove() {
    };
  }
}