/**************************************************************************
/* This class dumps image meta-information.
/*
/* Copyright (c) 2006 by Bernhard Bablok (mail@bablokb.de)
/*
/* This program is free software; you can redistribute it and/or modify
/* it under the terms of the GNU General Public License as published
/* by  the Free Software Foundation; either version 2 of the License or
/* (at your option) any later version.
/*
/* This program 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 General Public License for more details.
/*
/* You should have received a copy of the GNU General Public License
/* along with this program; see the file COPYING.  If not, write to
/* the Free Software Foundation Inc., 59 Temple Place - Suite 330,
/* Boston, MA  02111-1307 USA
/**************************************************************************/

import java.io.*;
import java.util.*;
import javax.imageio.*;
import javax.imageio.stream.*;
import javax.imageio.metadata.*;
import org.w3c.dom.*;


/**
   This class dumps image meta-information.

   @version $Revision: 1.3 $
   @author  $Author: bablokb $
*/

public class PrintMeta {

  //////////////////////////////////////////////////////////////////////////////

  /**
     Constructor.
  */

  public PrintMeta() {
  }

  //////////////////////////////////////////////////////////////////////////////

  /**
     Dump meta-data of a file to standard output.
  */

  public void dump(File f) throws Exception {
    ImageReader reader = getReader(f);
    IIOMetadata metaData = reader.getImageMetadata(0);
    if (metaData == null) {
      System.out.println("no meta-data for file " + f.toString());
      return;
    }
    String[] formats = metaData.getMetadataFormatNames();
    for (int i=0; i<formats.length;++i) {
      Node rootNode = metaData.getAsTree(formats[i]);
      printNode(rootNode,0);
    }
  }

  //////////////////////////////////////////////////////////////////////////////

  /**
     Print spaces to indent output.
  */

  void indent(int level) {
    for (int i=0; i<level; ++i) {
      System.out.print("  ");
    }
  } 

  //////////////////////////////////////////////////////////////////////////////

  /**
     Print a meta-data node with correct indentation level.
  */

  void printNode(Node node,int level) {
    indent(level);
    // start of opening tag
    System.out.print("<" + node.getNodeName());
    NamedNodeMap map = node.getAttributes();

    // attributes
    if (map != null) {
      for (int i=0; i<map.getLength(); ++i) {
	Node attrib = map.item(i);
	System.out.print(" " + attrib.getNodeName() +
			 "=\"" + attrib.getNodeValue() + "\"");
      }
    }

    // child nodes
    Node child = node.getFirstChild();
    if (child != null) {
      // end of tag
      System.out.println(">");
      // recursively print child tags
      while (child != null) {
	printNode(child,level+1);
	child = child.getNextSibling();
      }
      indent(level);

      // start of closing tag
      System.out.println("</" + node.getNodeName() + ">");
    } else {
      System.out.println("/>");
    }
  }

  //////////////////////////////////////////////////////////////////////////////

  /**
     Get a configured reader for the image.
  */

  protected ImageReader getReader(File f) throws IOException {
    ImageInputStream iis = ImageIO.createImageInputStream(f);
    Iterator readers = ImageIO.getImageReaders(iis);
    ImageReader reader = (ImageReader) readers.next();
    reader.setInput(iis,true);
    return reader;
  }

  //////////////////////////////////////////////////////////////////////////////

  /**
     Iterate over all images.
  */

  public void processImages(String[] args) throws Exception {
    for (int i=0; i<args.length; ++i) {
      File imgFile = new File(args[i]);
      if (imgFile.exists())
	dump(imgFile);
      else
	System.out.println("file " + args[i] + " doesn't exist");
    }
  }

  //////////////////////////////////////////////////////////////////////////////

  /**
     Main method. Pass files as arguments.
  */

  public static void main(String[] args) {
    if (args.length < 1) {
      System.out.println("usage: java " +
                                   PrintMeta.class.getName() + " file [...]");
      System.exit(3);
    }

    try {
      PrintMeta printer = new PrintMeta();
      printer.processImages(args);
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
}