/**
 * <copyright> Copyright 2006 by Know-Center, Graz, Austria </copyright>
 * PDF-AS has been contracted 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.
 *
 * $Id: SplitStrings.java,v 1.1 2006/08/30 14:02:35 wprinz Exp $
 */
package at.knowcenter.wag.egov.egiz.pdf;

import java.util.List;

import org.apache.commons.lang.ArrayUtils;


/**
 * Class that helps filling out the placeholders.
 * 
 * <p>
 * This class treats a sequence of placeholder StringInfos like a continuous
 * data area that can be filled out regarding the boundaries.
 * </p>
 * 
 * @author wprinz
 */
public class SplitStrings
{
  /**
   * The byte used to fill unused bytes in the placeholders.
   */

  public static final byte FILL_BYTE = ' ';
  
  /**
   * The underlying PDF.
   */
  protected byte[] pdf = null;

  /**
   * The strings to be filled out.
   */
  protected StringInfo[] strings = null;

  /**
   * The current string which is written to.
   */
  protected int cur_string = 0;

  /**
   * The current write position within the current string.
   */
  protected int cur_pos = 0;

  /**
   * Constructor.
   * 
   * @param pdf
   *          The underlying PDF.
   * @param strings
   *          The strings to be filled out.
   */
  public SplitStrings(byte[] pdf, List strings)
  {
    this.pdf = pdf;
    this.strings = new StringInfo[strings.size()];
    for (int i = 0; i < strings.size(); i++)
    {
      StringInfo si = (StringInfo) strings.get(i);
      this.strings[i] = si;
    }
  }

  /**
   * Returns how many bytes are still available in the current string.
   * 
   * @return Returns the number of bytes that are still available. (positive
   *         integer, or zero if none are available)
   */
  public int getAvailable()
  {
    return this.strings[this.cur_string].string_length - this.cur_pos;
  }

  /**
   * Tells, if the whole data would fit into the current string.
   * 
   * @param data
   *          The data to be matched for fitting
   * @return Returns true, if the whole data fits, false otherwise.
   */
  public boolean fits(byte[] data)
  {
    return getAvailable() >= data.length;
  }

  /**
   * Writes the data into the current string.
   * 
   * <p>
   * Note that the data must fit in.
   * </p>
   * @param data The data to be written.
   */
  public void write(byte[] data)
  {
    if (!fits(data))
    {
      throw new IllegalArgumentException("The data doesn't fit in.");
    }

    System.arraycopy(data, 0, this.pdf, this.strings[this.cur_string].string_start + this.cur_pos, data.length);
    this.cur_pos += data.length;

    if (data[data.length-1] == '\n') { 
       this.cur_pos -= 1; // remove \n from output
       newline();
    }
  }

  /**
   * Fills the current string with the fill character and moves on to the next
   * string.
   * 
   */
  public void newline()
  {
    int end = this.strings[this.cur_string].string_start + this.strings[this.cur_string].string_length;
    for (int i = this.strings[this.cur_string].string_start + this.cur_pos; i < end; i++)
    {
      pdf[i] = FILL_BYTE;
    }

    this.cur_string++;
    this.cur_pos = 0;
  }

  /**
   * Fills all rest bytes with the fill character.
   * 
   * <p>
   * This should be called when everything is finished to fill all strings properly.
   * </p>
   */
  public void fillRest()
  {
    while (this.cur_string < this.strings.length)
    {
      newline();
    }
  }
  
  /**
   * Tells, if the current line is valid.
   * @return Returns true, if this is a line that can be written to.
   */
  public boolean isValidLine ()
  {
    return this.cur_string < this.strings.length;
  }
}