/*
 * Copyright (c) 2010, Manuel Mausz. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 *   - The names of the authors may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

import java.util.Collection;
import java.util.Iterator;
import java.io.ObjectOutputStream;
import java.io.IOException;

/*
 * Common static methods used by all applications
 *
 * @author Manuel Mausz (0728348)
 */
class Utils
{
  static class Shutdown
    extends java.lang.RuntimeException
  {
    public Shutdown()
    {
      super();
    }

    public Shutdown(String message)
    {
      super(message);
    }
  }

  /*==========================================================================*/

  public static <T> String join(final Collection<T> objs, final String delimiter)
  {
    if (objs == null || objs.isEmpty())
      return "";
    Iterator<T> iter = objs.iterator();
    StringBuffer buffer = new StringBuffer(iter.next().toString());
    while (iter.hasNext())
      buffer.append(delimiter).append(iter.next().toString());
    return buffer.toString();
  }

  /*--------------------------------------------------------------------------*/

  public static long parseHeaderNum(String[] args, int index)
  {
    long num = -1;
    try
    {
      if (args.length < index + 1)
        throw new NumberFormatException();
      num = Long.parseLong(args[index]);
      if (num <= 0)
        throw new NumberFormatException();
    }
    catch(NumberFormatException e)
    {
      System.err.println("Invalid network paket from peer");
    }
    return num;
  }

  /*------------------------------------------------------------------------*/

  public static void sendOutput(ObjectOutputStream out, String[] msgs)
    throws IOException
  {
    out.writeUTF("!output " + msgs.length);
    for(String msg : msgs)
      out.writeUTF(msg);
    out.flush();
  }

  /*------------------------------------------------------------------------*/

  public static void sendOutput(ObjectOutputStream out, String msg)
    throws IOException
  {
    String[] tmp = { msg };
    sendOutput(out, tmp);
  }

  /*------------------------------------------------------------------------*/

  public static void sendError(ObjectOutputStream out, String[] msgs)
    throws IOException
  {
    out.writeUTF("!error " + msgs.length);
    for(String msg : msgs)
      out.writeUTF(msg);
    out.flush();
  }

  /*------------------------------------------------------------------------*/

  public static void sendError(ObjectOutputStream out, String msg)
    throws IOException
  {
    String[] tmp = { "Error: " + msg };
    sendError(out, tmp);
  }
}