/*

  * Copyright 2008, 2009 Ange Optimization ApS

  *

  * 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.

  */

 package eu.simuline.octave.io;

 import static eu.simuline.octave.io.OctaveIO.readerReadLine;

 import java.io.BufferedReader;

 import java.io.Reader;

 import java.util.Map;

 import eu.simuline.octave.exception.OctaveParseException;

 import eu.simuline.octave.exec.ReadFunctor;

 import eu.simuline.octave.type.OctaveObject;

 /**

  * Functor that reads a single variable named {@link #name} 

  * into {@link #data} via {@link #doReads(Reader)}. 

  */

 // ER: Very strange: whereas this read functor reads a single variable only 

 // the according write functor writes a map: 

 // see OctaveIO 

 final class DataReadFunctor implements ReadFunctor {

     /**

      * The name of the variable to be read. 

      */

     private final String name;

     /**

      * After {@link #doReads(Reader)} returns, this contains the read data. 

      */

     private OctaveObject data;

     /**

      * @param name

      */

     DataReadFunctor(final String name) {

         this.name = name;

     }

     /**

      * @param reader

      */

     @Override

     public void doReads(final Reader reader) {

         final BufferedReader bufferedReader = new BufferedReader(reader);

         final String createByOctaveLine = readerReadLine(bufferedReader);

         if (createByOctaveLine == null || 

             !createByOctaveLine.startsWith("# Created by Octave")) {

             throw new OctaveParseException

                 ("Not created by Octave?: '" + createByOctaveLine + "'");

         }

         final Map<String, OctaveObject> map = 

             OctaveIO.readWithName(bufferedReader);

         if (map.size() != 1) {

             throw new OctaveParseException

                 ("Expected map of size 1 but got " + map + "'");

         }

         if (!map.containsKey(this.name)) {

             throw new OctaveParseException

                 ("Expected variable named '" + this.name + 

                  "' but got '" + map + "'");

         }

         this.data = map.get(this.name);

     }

     /**

      * @return the data

      */

     public OctaveObject getData() {

         return this.data;

     }

 }