/**
 *#########################################################################
 *
 * A component of the Gatherer application, part of the Greenstone digital
 * library suite from the New Zealand Digital Library Project at the
 * University of Waikato, New Zealand.
 *
 * Author: John Thompson, Greenstone Digital Library, University of Waikato
 *
 * Copyright (C) 1999 New Zealand Digital Library Project
 *
 * 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; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *########################################################################
 */
package org.greenstone.gatherer.valuetree;

import java.util.*;
import javax.swing.tree.*;
import org.greenstone.gatherer.Gatherer;
import org.greenstone.gatherer.msm.ElementWrapper;
import org.greenstone.gatherer.msm.MSMUtils;
import org.greenstone.gatherer.util.PatternTokenizer;
import org.greenstone.gatherer.util.Utility;
import org.w3c.dom.*;
/*
 * @author John Thompson, Greenstone Digital Library, University of Waikato
 * @version 2.1
 */
public class GValueModel 
    extends DefaultTreeModel {

    static final public String PATH_SEP = "\\\\";
    static final public String PATH_SEP_PATTERN = "\\\\\\\\";

    private ElementWrapper element;

    public GValueModel() {
	super(new DefaultMutableTreeNode("Temp"));
    }

    public GValueModel(String root) {
	super(new DefaultMutableTreeNode(root));
    }

    public GValueModel(ElementWrapper e) {
	super(new DefaultMutableTreeNode("Temp"));
	this.element = e;
	// Load the template value tree document.
	Document document = MSMUtils.getValueTreeTemplate();
	Element new_root = document.getDocumentElement();
	new_root.setAttribute("element", e.getName());
	root = new GValueNode(new_root);
    }

    public GValueModel(ElementWrapper e, Document document) {
	super(new DefaultMutableTreeNode("Temp"));
	this.element = e;
	Element new_root = document.getDocumentElement();
	new_root.setAttribute("element", e.getName());
	root = new GValueNode(new_root);
    }

    /** Value may include path ie news\newssw */
    public GValueNode addValue(String value) {     
       try {
	    // Tokenize the string using the escaped character
	    PatternTokenizer tokenizer = new PatternTokenizer(value, PATH_SEP);
	    GValueNode subject = (GValueNode) root;
	    while(tokenizer.hasMoreTokens() && subject != null) {
		String token = tokenizer.nextToken();
		subject = addValue(token, subject, null);
	    }
	    return subject;
	}
	catch (Exception error) {
	    error.printStackTrace();
	}
	return null;
    }

   public GValueNode addValue(String value, GValueNode subject, String alias) {
	// To add a value we must first ensure it isn't already present in -this- nodes children. The bummer is that the nice getElements functions search the whole tree so...
	GValueNode value_node = subject.getValue(value);
	if(value_node == null) {
	    // Now add the new value.
	    Document document = subject.getElement().getOwnerDocument();
	    // Now we create a new subject and add it subject
	    Element new_subject = document.createElementNS("","Subject");
	    Element new_value = document.createElementNS("","Value");
	    new_subject.appendChild(new_value);
	    Text new_text = document.createTextNode(value);
	    new_value.appendChild(new_text);
	    if(alias != null && alias.length() > 0) {
		Element new_alias = document.createElementNS("","Alias");
		new_subject.appendChild(new_alias);
		Text new_alias_text = document.createTextNode(alias);
		new_alias.appendChild(new_alias_text);					
	    } 
	    value_node = new GValueNode(new_subject);
	    ///ystem.err.println("(GValueModel) addValue()... " + value_node);
	    
	    // Figure out where this node will be inserted in subjects 
	    // children.
	    int position = -1;
	    for(int i = 0; position == -1 && i < subject.getChildCount(); i++) {
		Object sibling = subject.getChildAt(i);
		int rel_pos = value.compareTo(sibling.toString());
		///ystem.err.println("'"+value+"'.compareTo('"+sibling+"') = " + rel_pos);
		if(rel_pos <= 0) {
		    position = i;
		}
	    }
	    if(position == -1) {
		position = subject.getChildCount();
	    }
	    // Insert it. If position is still -1, append it to the end of subjects children.
	    ///ystem.err.println("Inserting '" + value + "' at position " + position);
	    insertNodeInto(value_node, subject, position);
	    ///ystem.err.println("(GValueModel) Done insert node into...");
	    // SynchronizedTreeModelTools.insertNodeInto(this, subject, value_node);
	    // Inform listeners that we've changed.
	    Gatherer.c_man.getCollection().msm.fireValueChanged(element, null, this);
	}
	return value_node;
    }

    public Document getDocument() {
	return ((GValueNode)root).getElement().getOwnerDocument();
    }

    public ElementWrapper getElement() {
	return element;
    }

    /** Retrieve the hindex for a certain value within the value tree.
     * @param value The value whose index you wish to determine as a <strong>String</strong>.
     * @return A <strong>String</strong> containing an index such as "1", "2.1" or "18.2.5".
     */ 
    public String getHIndex(String value) {
	///ystem.err.println("getHIndex(" + value + ")");
	return getHIndex((GValueNode) root, value, null);
    }

    /** Retrieve a value node given its hierarchical reference or value.
     * @param index The hierarchy index or value as a <strong>String</strong>.
     */
    public GValueNode getValue(String index_str) {
	///ystem.err.println("Retrieve the value for: " + index_str);
	GValueNode result = null;
	if(isHierarchy() && Utility.isIndex(index_str)) {
	    // StringTokenize the index
	    StringTokenizer tokenizer = new StringTokenizer(index_str, ".");
	    result = (GValueNode) root;
	    // Using the index numbers retrieve the appropriate node.
	    try {
		while(result != null && tokenizer.hasMoreTokens()) {
		    int index = Integer.parseInt(tokenizer.nextToken()) - 1;
		    // Retrieve the index'th child of the current result node
		    if(0 <= index && index < result.getChildCount()) {
			result = (GValueNode) result.getChildAt(index);
		    }
		    // Otherwise we're broken.
		    else {
			///ystem.err.println("There is no " + index + "th childnode of " + result);
			result = null;
		    }
		}
	    }
	    // Most likely caused by parseInt throwing a wobbly.
	    catch (Exception error) {
		result = null;
	    }
	}
	if(result == null) {
	    ///ystem.err.println("No existing value. Adding " + index_str);
	    result = addValue(index_str);
	}
	return result;
    }

    public boolean isHierarchy() {
	boolean result = false;
	// We are a hierarchy if our element says so....
	if(element.isHierarchy()) {
	    return true;
	}
	// Or if our children are actually a hierarchy.
	for(int i = 0; i < root.getChildCount() && !result; i++) {
	    GValueNode node = (GValueNode) root.getChildAt(i);
	    if(node != null && node.getChildCount() > 0) {
		result = true;
	    }
	}
	return result;
    }

    public void removeValue(GValueNode child) {
	//SynchronizedTreeModelTools.removeNodeFromParent(this, child);
	removeNodeFromParent(child);
	Gatherer.c_man.getCollection().msm.fireValueChanged(new ElementWrapper(child.getElement()), null, this);
    }

    public void removeValue(String value) {
	// Retrieve the node to be removed.
	GValueNode node = getValue(value);
	if(node != null) {
	    removeValue(node);
	}
    }

    public int size() {
	return size(root);
    }

    private int size(TreeNode current) {
	int size = 1;
	for(int i = 0; i < current.getChildCount(); i++) {
	    size = size + size(current.getChildAt(i));
	}
	return size;
    }

    public String toString() {
	return element.toString();
    }

    public Vector traverseTree() {
	Vector contents = new Vector();
	contents.addAll(traverseTree((GValueNode) root));
	contents.remove((GValueNode) root);
	return contents;
    }

    /** Called to update a certain value of metadata within a specific
     * subject within a sbject hierarchy. 
     * Note that this simply in turn calls removeValue() to deal with the
     * old value, then addValue() to account for the new. 
     * @param new_value A String representing the updated value.
     * @param old_value A String representing the old value.
     * @param subject An Element representing the subject you wish to update 
     * this value in.
     */ 
    public GValueNode updateValue(String new_value, String old_value, GValueNode subject) {
	return addValue(new_value, subject, null);
    }

    private GValueModel copy() {
	Element document_element = ((GValueNode) root).getElement();
	Document document_copy = MSMUtils.getValueTreeTemplate();
	Element document_copy_element = document_copy.getDocumentElement();
	document_copy_element.setAttribute("element", element.getName());
	for(Node node = document_element.getFirstChild(); node != null; node = node.getNextSibling()) {
	    if(node.getNodeName().equals("Subject")) {
		Node node_copy = document_copy.importNode(node, true);
		document_copy_element.appendChild(node_copy);
	    }
	}
	return new GValueModel(element, document_copy); 				
    }

    private String getHIndex(GValueNode node, String value, String index) {
	for(int i = node.size(); i != 0; i--) {
	    GValueNode next = (GValueNode)node.get(i - 1);
	    String next_str = next.toString();
	    if(value.startsWith(next_str)) {
		if(index == null) {
		    index = String.valueOf(i);
		}
		else {
		    index = index + "." + i;
		}
		value = value.substring(next.toString().length());
		if(value.startsWith(PATH_SEP)) {
		    value = value.substring(2);
		    index = getHIndex(next, value, index);
		}
		return index;
	    }
	}
	return index;
    }

    private Vector traverseTree(GValueNode node) {
	Vector contents = new Vector();
	contents.add(node);
	for(int i = 0; i < node.getChildCount(); i++) {
	    contents.addAll(traverseTree((GValueNode)node.getChildAt(i)));
	}
	return contents;
    }
}