/*

  * 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.commons.lang3.text.translate;

 import java.io.IOException;

 import java.io.Writer;

 import java.util.HashMap;

 /**

  * Translates a value using a lookup table.

  * 

  * @since 3.0

  * @version $Id: LookupTranslator.java 1436770 2013-01-22 07:09:45Z ggregory $

  */

 public class LookupTranslator extends CharSequenceTranslator {

     private final HashMap<CharSequence, CharSequence> lookupMap;

     private final int shortest;

     private final int longest;

     /**

      * Define the lookup table to be used in translation

      *

      * @param lookup CharSequence[][] table of size [*][2]

      */

     public LookupTranslator(final CharSequence[]... lookup) {

         lookupMap = new HashMap<CharSequence, CharSequence>();

         int _shortest = Integer.MAX_VALUE;

         int _longest = 0;

         if (lookup != null) {

             for (final CharSequence[] seq : lookup) {

                 this.lookupMap.put(seq[0], seq[1]);

                 final int sz = seq[0].length();

                 if (sz < _shortest) {

                     _shortest = sz;

                 }

                 if (sz > _longest) {

                     _longest = sz;

                 }

             }

         }

         shortest = _shortest;

         longest = _longest;

     }

     /**

      * {@inheritDoc}

      */

     @Override

     public int translate(final CharSequence input, final int index, final Writer out) throws IOException {

         int max = longest;

         if (index + longest > input.length()) {

             max = input.length() - index;

         }

         // descend so as to get a greedy algorithm

         for (int i = max; i >= shortest; i--) {

             final CharSequence subSeq = input.subSequence(index, index + i);

             final CharSequence result = lookupMap.get(subSeq);

             if (result != null) {

                 out.write(result.toString());

                 return i;

             }

         }

         return 0;

     }

 }