/*
 * $Id: Watermarker.java,v 1.9 2007/02/12 11:30:10 blowagie Exp $
 * $Name:  $
 *
 * Copyright 2005 by Carsten Hammer and Bruno Lowagie
 *
 * The contents of this file are subject to the Mozilla Public License Version 1.1
 * (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the License.
 *
 * The Original Code is 'iText, a free JAVA-PDF library'.
 *
 * The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
 * the Initial Developer are Copyright (C) 1999, 2000, 2001, 2002 by Bruno Lowagie.
 * All Rights Reserved.
 * Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
 * are Copyright (C) 2000, 2001, 2002 by Paulo Soares. All Rights Reserved.
 *
 * Contributor(s): all the names of the contributors are added in the source code
 * where applicable.
 *
 * Alternatively, the contents of this file may be used under the terms of the
 * LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
 * provisions of LGPL are applicable instead of those above.  If you wish to
 * allow use of your version of this file only under the terms of the LGPL
 * License and not to allow others to use your version of this file under
 * the MPL, indicate your decision by deleting the provisions above and
 * replace them with the notice and other provisions required by the LGPL.
 * If you do not delete the provisions above, a recipient may use your version
 * of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the MPL as stated above or under the terms of the GNU
 * Library General Public License as published by the Free Software Foundation;
 * either version 2 of the License, or any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Library general Public License for more
 * details.
 *
 * If you didn't download this code from the following link, you should check if
 * you aren't using an obsolete version:
 * http://www.lowagie.com/iText/
 */
package com.lowagie.tools.plugins;

import java.io.File;
import java.io.FileOutputStream;

import javax.swing.JInternalFrame;
import javax.swing.JOptionPane;

import com.lowagie.text.Rectangle;
import com.lowagie.text.pdf.BaseFont;
import com.lowagie.text.pdf.PdfContentByte;
import com.lowagie.text.pdf.PdfGState;
import com.lowagie.text.pdf.PdfReader;
import com.lowagie.text.pdf.PdfStamper;
import com.lowagie.tools.arguments.FileArgument;
import com.lowagie.tools.arguments.PdfFilter;
import com.lowagie.tools.arguments.ToolArgument;

/**
 * This tool lets you add a text watermark to all pages of a document.
 */
public class Watermarker
    extends AbstractTool {

  static {
    addVersion("$Id: Watermarker.java,v 1.9 2007/02/12 11:30:10 blowagie Exp $");
  }

  /**
   * This tool lets you add a text watermark to all pages of a document.
   */
  public Watermarker() {
    super();
    arguments.add(new FileArgument(this, "srcfile",
                                   "The file you want to watermark", false,
                                   new PdfFilter()));
    arguments.add(new ToolArgument(this, "watermark",
                                   "The text that can be used as watermark",
                                   String.class.getName()));
    arguments.add(new ToolArgument(this, "fontsize",
                                   "The fontsize of the watermark text",
                                   String.class.getName()));
    arguments.add(new ToolArgument(this, "opacity",
                                   "The opacity of the watermark text",
                                   String.class.getName()));
    arguments.add(new FileArgument(this, "destfile",
                                   "The file to which the watermarked PDF has to be written",
                                   true, new PdfFilter()));

  }

  /**
   * Creates the internal frame.
   */
  protected void createFrame() {
    internalFrame = new JInternalFrame("Watermark", true, false, true);
    internalFrame.setSize(300, 80);
    internalFrame.setJMenuBar(getMenubar());
    System.out.println("=== Watermark OPENED ===");
  }

  /**
   * Executes the tool (in most cases this generates a PDF file).
   */
  public void execute() {
    try {
      if (getValue("srcfile") == null) {
        throw new InstantiationException(
            "You need to choose a sourcefile");
      }
      if (getValue("destfile") == null) {
        throw new InstantiationException(
            "You need to choose a destination file");
      }
      if (getValue("watermark") == null) {
        throw new InstantiationException(
            "You need to add a text for the watermark");
      }
      int fontsize = Integer.parseInt( (String) getValue("fontsize"));
      float opacity = Float.parseFloat( (String) getValue("opacity"));
      BaseFont bf = BaseFont.createFont("Helvetica", BaseFont.WINANSI,
                                        false);
      PdfReader reader = new PdfReader( ( (File) getValue("srcfile"))
                                       .getAbsolutePath());
      int pagecount = reader.getNumberOfPages();
      PdfGState gs1 = new PdfGState();
      gs1.setFillOpacity(opacity);
      String text = (String) getValue("watermark");
      PdfStamper stamp = new PdfStamper(reader, new FileOutputStream(
          (File) getValue("destfile")));
      float txtwidth = bf.getWidthPoint(text, fontsize);
      for (int i = 1; i <= pagecount; i++) {
        PdfContentByte seitex = stamp.getOverContent(i);
        Rectangle recc = reader.getCropBox(i);
        float winkel = (float) Math.atan(recc.height() / recc.width());
        float m1 = (float) Math.cos(winkel);
        float m2 = (float) - Math.sin(winkel);
        float m3 = (float) Math.sin(winkel);
        float m4 = (float) Math.cos(winkel);
        float xoff = (float) ( -Math.cos(winkel) * txtwidth / 2 - Math
                              .sin(winkel)
                              * fontsize / 2);
        float yoff = (float) (Math.sin(winkel) * txtwidth / 2 - Math
                              .cos(winkel)
                              * fontsize / 2);
        seitex.saveState();
        seitex.setGState(gs1);
        seitex.beginText();
        seitex.setFontAndSize(bf, fontsize);
        seitex.setTextMatrix(m1, m2, m3, m4, xoff + recc.width() / 2,
                             yoff + recc.height() / 2);
        seitex.showText(text);
        seitex.endText();
        seitex.restoreState();
      }
      stamp.close();
    }
    catch (Exception e) {
      JOptionPane.showMessageDialog(internalFrame, e.getMessage(), e
                                    .getClass().getName(),
                                    JOptionPane.ERROR_MESSAGE);
      System.err.println(e.getMessage());
    }
  }

  /**
   * Gets the PDF file that should be generated (or null if the output isn't a
   * PDF file).
   *
   * @return the PDF file that should be generated
   * @throws InstantiationException
   */
  protected File getDestPathPDF() throws InstantiationException {
    return (File) getValue("destfile");
  }

  /**
   * Indicates that the value of an argument has changed.
   *
   * @param arg
   *            the argument that has changed
   */
  public void valueHasChanged(ToolArgument arg) {
    if (internalFrame == null) {
      // if the internal frame is null, the tool was called from the
      // commandline
      return;
    }

  }

  /**
   * This methods helps you running this tool as a standalone application.
   *
   * <p>Call it like this from commandline:
   * java com.lowagie.tools.plugins.Watermarker input.pdf Draft 230 0.2 output.pdf
   *
   * <p>"input.pdf" is the input file name to be processed
   * <p>"Draft" is the text written as transparent "watermark" on top of each page
   * <p>"230" is the font size
   * <p>"0.2" is the opacity (1.0 completely opaque, 0.0 completely transparent)
   * <p>"output.pdf" is the output file name
   *
   * <p>Call it from within other Java code:
   *
   * <p>Watermarker.main(new String[]{"input.pdf","Draft","230","0.2","output.pdf"});
   *
   * @param args the srcfile, watermark text and destfile
   */
  public static void main(String[] args) {
    Watermarker watermarker = new Watermarker();
    if (args.length != 5) {
      System.err.println(watermarker.getUsage());
    }
    watermarker.setArguments(args);
    watermarker.execute();
  }
}
