/*
 * $Id$
 * Copyright (c) 2005-2007 Bruno Lowagie, Carsten Hammer
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

/*
 * This class was originally published under the MPL by Bruno Lowagie
 * and Carsten Hammer.
 * It was a part of iText, a Java-PDF library. You can now use it under
 * the MIT License; for backward compatibility you can also use it under
 * the MPL version 1.1: http://www.mozilla.org/MPL/
 * A copy of the MPL license is bundled with the source code FYI.
 */

package com.lowagie.toolbox.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.toolbox.AbstractTool;
import com.lowagie.toolbox.arguments.AbstractArgument;
import com.lowagie.toolbox.arguments.FileArgument;
import com.lowagie.toolbox.arguments.FloatArgument;
import com.lowagie.toolbox.arguments.IntegerArgument;
import com.lowagie.toolbox.arguments.StringArgument;
import com.lowagie.toolbox.arguments.filters.PdfFilter;

/**
 * This tool lets you add a text watermark to all pages of a document.
 * @since 2.1.1 (imported from itexttoolbox project)
 */
public class Watermarker extends AbstractTool {

    static {
        addVersion("$Id$");
    }

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

    /**
     * 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.getHeight() /
                                                 recc.getWidth());
                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.getWidth() / 2,
                                     yoff + recc.getHeight() / 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(AbstractArgument arg) {
        if (internalFrame == null) {
            // if the internal frame is null, the tool was called from the
            // command line
            return;
        }
        if (destfile.getValue() == null &&
            arg.getName().equalsIgnoreCase("srcfile")) {
            String filename = arg.getValue().toString();
            String filenameout = filename.substring(0, filename.indexOf(".",
                    filename.length() - 4)) + "_out.pdf";
            destfile.setValue(filenameout);
        }
    }

    /**
     * This methods helps you running this tool as a standalone application.
     *
     * <p>Call it like this from command line:
     * 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.setMainArguments(args);
        watermarker.execute();
    }
}
