package semdiff;

/*
 *     Unibz - XML Data Management 2010/2011 - Miniproject
 *
 *     semdiff
 *
 *     we would like to develop a command line application
 *     that tells us whether two XML documents are *semantically*
 *     identical or not
 *
 *     note that being semantically identical is a "weaker" condition
 *     than being syntactically identical - XML doesn't for example
 *     mandate the order of attributes in an element and ignores
 *     whitespace in certain cases; documents that differ only by
 *     such things would be considered semantically identical while
 *     being syntactically different
 *
 *     we start from the DOM pretty printer code seen in lesson 05
 *     and work from there
 *
 *     -- chris
 */

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import java.io.File;
import java.util.ArrayList;
import org.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;


public class Main {


    public static void main(String[] argv) throws Exception {

      DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();

      // factory.setValidating(true);
      // factory.setNamespaceAware(true);

      DocumentBuilder builder = factory.newDocumentBuilder();
      Document doca;
      Document docb;
      doca = builder.parse(new File("/Users/chris/prj/unibz/xml/06_samples/recipe1.xml"));
      docb = builder.parse(new File("/Users/chris/prj/unibz/xml/06_samples/recipe2.xml"));

      StringBuffer bufa = new StringBuffer("");
      StringBuffer bufb = new StringBuffer("");

      // let's call our traversal code
      traverse(doca.getDocumentElement(), 0, bufa);
      traverse(docb.getDocumentElement(), 0, bufb);

      // System.out.println(bufa.toString());
      // System.out.println(bufb.toString());
      if (bufa.toString().equals(bufb.toString())) {
          System.out.println("documents are semantically identical");
      } else {
          System.out.println("documents are semantically different");
      }
    }

    private static final int OPEN=1;
    private static final int CLOSE=2;


    private static void traverse(Node n, int level, StringBuffer buf) {
        int i;

        // find out what type of node this is

        short t = n.getNodeType();

        if (t == Document.ELEMENT_NODE) {
            buf.append(print_element(level, n, OPEN));
        } else if (t == Document.TEXT_NODE) {
            if (!is_empty(n)) {
                buf.append(print_text(level, n));
            }
        }

        NodeList nl = n.getChildNodes();
        if (nl.getLength() == 0) {
            return;
        }

        for (i = 0; i < nl.getLength(); i++) {
            traverse(nl.item(i), level + 1, buf);
        }

        if (t == Document.ELEMENT_NODE) {
            buf.append(print_element(level, n, CLOSE));
        }

    }

    static String print_element(int level, Node n, int mode) {
        String slash = "";
        String attr = "";
        if (mode == CLOSE) {
            slash = "/";
        }
        if (mode == OPEN) {
            NamedNodeMap amap = n.getAttributes();
            ArrayList<String> attr_list = new ArrayList<String>();
            int i;
            for (i = 0; i < amap.getLength(); i++) {
                String p = amap.item(i).getNodeName() +
                           "=\"" +
                           amap.item(i).getNodeValue() +
                           "\"";
                attr_list.add(p);
            }
            java.util.Collections.sort(attr_list);
            for (i = 0; i < attr_list.size(); i++) {
                attr += " " + attr_list.get(i);
            }
        }
        return get_indent(level) + "<" + slash + n.getNodeName() + attr + ">";
    }

    static String print_text(int level, Node n) {
        String txt = n.getNodeValue().trim();
        txt = txt.replaceAll("\\s+", " ");
        return get_indent(level) + txt;
    }


    static String get_indent(int level) {
        int i;
        StringBuffer buf = new StringBuffer();
        /*
        for (i = 0; i < level; i++) {
            buf.append("    ");
        }
        */
        return buf.toString();
    }

    static boolean is_empty(Node n) {

        String val = n.getNodeValue();
        val = val.replaceAll("\\s+", "");
        val = val.replaceAll("\n+", "");
        if (val.equals("")) {
            return true;
        }
        return false;

    }

}