/**
 * $Id: mxStylesheetCodec.java,v 1.1 2012/11/15 13:26:47 gaudenz Exp $
 * Copyright (c) 2006-2010, JGraph Ltd
 */
package com.mxgraph.io;

import com.mxgraph.util.mxUtils;
import com.mxgraph.view.mxStylesheet;
import org.w3c.dom.Element;
import org.w3c.dom.Node;

import java.util.Hashtable;
import java.util.Iterator;
import java.util.Map;

/**
 * Codec for mxStylesheets. This class is created and registered
 * dynamically at load time and used implicitely via mxCodec
 * and the mxCodecRegistry.
 */
public class mxStylesheetCodec extends mxObjectCodec {

  /**
   * Constructs a new model codec.
   */
  public mxStylesheetCodec() {
    this(new mxStylesheet());
  }

  /**
   * Constructs a new stylesheet codec for the given template.
   */
  public mxStylesheetCodec(Object template) {
    this(template, null, null, null);
  }

  /**
   * Constructs a new model codec for the given arguments.
   */
  public mxStylesheetCodec(Object template, String[] exclude, String[] idrefs, Map<String, String> mapping) {
    super(template, exclude, idrefs, mapping);
  }

  /**
   * Encodes the given mxStylesheet.
   */
  public Node encode(mxCodec enc, Object obj) {
    Element node = enc.document.createElement(getName());

    if (obj instanceof mxStylesheet) {
      mxStylesheet stylesheet = (mxStylesheet)obj;
      Iterator<Map.Entry<String, Map<String, Object>>> it = stylesheet.getStyles().entrySet().iterator();

      while (it.hasNext()) {
        Map.Entry<String, Map<String, Object>> entry = it.next();

        Element styleNode = enc.document.createElement("add");
        String stylename = entry.getKey();
        styleNode.setAttribute("as", stylename);

        Map<String, Object> style = entry.getValue();
        Iterator<Map.Entry<String, Object>> it2 = style.entrySet().iterator();

        while (it2.hasNext()) {
          Map.Entry<String, Object> entry2 = it2.next();
          Element entryNode = enc.document.createElement("add");
          entryNode.setAttribute("as", String.valueOf(entry2.getKey()));
          entryNode.setAttribute("value", getStringValue(entry2));
          styleNode.appendChild(entryNode);
        }

        if (styleNode.getChildNodes().getLength() > 0) {
          node.appendChild(styleNode);
        }
      }
    }

    return node;
  }

  /**
   * Returns the string for encoding the given value.
   */
  protected String getStringValue(Map.Entry<String, Object> entry) {
    if (entry.getValue() instanceof Boolean) {
      return ((Boolean)entry.getValue()) ? "1" : "0";
    }

    return entry.getValue().toString();
  }

  /**
   * Decodes the given mxStylesheet.
   */
  public Object decode(mxCodec dec, Node node, Object into) {
    Object obj = null;

    if (node instanceof Element) {
      String id = ((Element)node).getAttribute("id");
      obj = dec.objects.get(id);

      if (obj == null) {
        obj = into;

        if (obj == null) {
          obj = cloneTemplate(node);
        }

        if (id != null && id.length() > 0) {
          dec.putObject(id, obj);
        }
      }

      node = node.getFirstChild();

      while (node != null) {
        if (!processInclude(dec, node, obj) && node.getNodeName().equals("add") && node instanceof Element) {
          String as = ((Element)node).getAttribute("as");

          if (as != null && as.length() > 0) {
            String extend = ((Element)node).getAttribute("extend");
            Map<String, Object> style = (extend != null) ? ((mxStylesheet)obj).getStyles().get(extend) : null;

            if (style == null) {
              style = new Hashtable<String, Object>();
            }
            else {
              style = new Hashtable<String, Object>(style);
            }

            Node entry = node.getFirstChild();

            while (entry != null) {
              if (entry instanceof Element) {
                Element entryElement = (Element)entry;
                String key = entryElement.getAttribute("as");

                if (entry.getNodeName().equals("add")) {
                  String text = entry.getTextContent();
                  Object value = null;

                  if (text != null && text.length() > 0) {
                    value = mxUtils.eval(text);
                  }
                  else {
                    value = entryElement.getAttribute("value");

                  }

                  if (value != null) {
                    style.put(key, value);
                  }
                }
                else if (entry.getNodeName().equals("remove")) {
                  style.remove(key);
                }
              }

              entry = entry.getNextSibling();
            }

            ((mxStylesheet)obj).putCellStyle(as, style);
          }
        }

        node = node.getNextSibling();
      }
    }

    return obj;
  }

}
