package at.gv.egiz.smcc.util;



import java.util.Iterator;
import java.util.NoSuchElementException;

/*
 * Copyright 2011 by Graz University of Technology, Austria
 * MOCCA has been developed by the E-Government Innovation Center EGIZ, a joint
 * initiative of the Federal Chancellery Austria and Graz University of Technology.
 *
 * Licensed under the EUPL, Version 1.1 or - as soon they will be approved by
 * the European Commission - subsequent versions of the EUPL (the "Licence");
 * You may not use this work except in compliance with the Licence.
 * You may obtain a copy of the Licence at:
 * http://www.osor.eu/eupl/
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the Licence is distributed on an "AS IS" basis,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the Licence for the specific language governing permissions and
 * limitations under the Licence.
 *
 * This product combines work with different licenses. See the "NOTICE" text
 * file for details on the various modules and licenses.
 * The "NOTICE" text file is part of the distribution. Any derivative works
 * that you distribute must include a readable copy of the "NOTICE" text file.
 */



public class TLVSequence implements Iterable<TLV> {
  
  private byte[] bytes;
  
  public TLVSequence(byte[] bytes) {
    this.bytes = bytes;
  }

  @Override
  public Iterator<TLV> iterator() {
    return new TLVIterator();
  }
  
  public byte[] getValue(int tag) {
    for (TLV tlv : this) {
      if (tlv.getTag() == tag) {
        return tlv.getValue();
      }
    }
    return null;
  }

  @Override
  public String toString() {
    StringBuilder sb = new StringBuilder();
    for (TLV tlv : this) {
      sb.append(tlv).append('\n');
    }
    return sb.toString();
  }

  private class TLVIterator implements Iterator<TLV> {

    private int pos = 0;
    
    @Override
    public boolean hasNext() {
      return (bytes.length - pos > 2);
    }

    @Override
    public TLV next() {
      if (hasNext()) {
        TLV tlv = new TLV(bytes, pos);
        pos += 1 + tlv.getLengthFieldLength() + tlv.getLength();
        return tlv;
      } else {
        throw new NoSuchElementException();
      }
    }

    @Override
    public void remove() {
      throw new UnsupportedOperationException();
    }
    
  }
  
}