/*******************************************************************************
 * Copyright (c) 2003, 2008 IBM Corporation and Others
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Kentarou FUKUDA - initial API and implementation
 *******************************************************************************/

package org.eclipse.actf.visualization.eval.guideline;

import java.io.InputStream;
import java.util.HashMap;
import java.util.Stack;
import java.util.Vector;

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.eclipse.actf.visualization.eval.IGuidelineItem;
import org.eclipse.ui.PlatformUI;
import org.xml.sax.Attributes;
import org.xml.sax.helpers.DefaultHandler;


public class GuidelineItemReader extends DefaultHandler {
    private static final String GUIDELINE = "guideline";

    private static final String MIMETYPES = "mimetypes";

    private static final String MIMETYPE = "mimetype";

    private static final String ITEMS = "items";

    private static final String GITEM = "gItem";

    private static final String LEVELS = "levels";

    private static final String LEVEL = "level";

    private static final String NAME = "name";

    private static final String ID = "id";

    private static final String HELP_URL = "helpUrl";

    private static final String ORDER = "order";

    private static final String DESCRIPTION = "description";

    private static final String CATEGORY = "category";

    // TODO id,level-> attribute url -> lang

    private static final short IN_GUIDELINE = 0;

    private static final short IN_LEVELS = 1;

    private static final short IN_ITEMS = 2;

    private static final short IN_ITEM = 3;

    private static final short IN_MIMETYPES = 4;

    private static final short IN_LEVEL = 5;

    public static GuidelineData getGuidelineData(InputStream is) {
        GuidelineItemReader glir = new GuidelineItemReader();
        try {
            SAXParserFactory spfactory = SAXParserFactory.newInstance();
            SAXParser parser = spfactory.newSAXParser();
            parser.parse(is, glir);
        } catch (Exception e) {
        }
        if (glir.isSucceed() && glir.guidelineName.length() > 0) {
            return (new GuidelineData(glir.guidelineName, glir.order, glir.category, glir.description, glir.levels,
                    glir.categories, glir.descriptions, glir.mimetypes, glir.itemMap));
        } else {
            // TODO dialog
            return (null);
        }
    }

    private Vector<String> levelsV = new Vector<String>();

    private Vector<String> descriptionsV = new Vector<String>();

    private Vector<String> categoriesV = new Vector<String>();

    private Vector<String> mimeV = new Vector<String>();

    private IGuidelineItem curItem = new GuidelineItem("");

    private Stack<Short> statusStack = new Stack<Short>();

    private String curValue;

    private HashMap<String, IGuidelineItem> itemMap;

    private String guidelineName;

    private int order;

    // for sub-levels
    private String levels[] = new String[0];

    private String descriptions[] = new String[0];

    private String categories[] = new String[0];

    // for root-level guideline
    private String description = "";

    private String category = "";

    private String mimetypes[] = new String[0];

    private short status = IN_GUIDELINE;

    private boolean succeed = false;

    /**
     * 
     */
    public GuidelineItemReader() {
        itemMap = new HashMap<String, IGuidelineItem>();
    }

    /**
     * 
     */
    public void characters(char[] ch, int offset, int length) {

        if (length > 0) {
            curValue += (new String(ch, offset, length));
        }
    }

    /**
     * 
     */
    public void endDocument() {
        levels = new String[levelsV.size()];
        levelsV.toArray(levels);

        categories = new String[categoriesV.size()];
        categoriesV.toArray(categories);

        descriptions = new String[descriptionsV.size()];
        descriptionsV.toArray(descriptions);

        mimetypes = new String[mimeV.size()];
        mimeV.toArray(mimetypes);

        // TODO validation
        succeed = true;
    }

    private String getLocalGuidelineURL(String url) {
    	if (url.startsWith("${")) {
    		int bundleNameEnd = url.indexOf("}");
    		if (bundleNameEnd==-1) return null;    		
    		String bundleName = url.substring(2, bundleNameEnd);
    		String href = "/" + bundleName + "/" + url.substring(bundleNameEnd+2);
    		return PlatformUI.getWorkbench().getHelpSystem().resolve(href, true).toString();    		
    	}
    	return null;
    }
    
    /**
     * 
     */
    public void endElement(String uri, String localName, String qName) {

        // TODO
        if (qName.equalsIgnoreCase(GITEM)) {
            itemMap.put(curItem.getId(), curItem);
            if (!statusStack.isEmpty()) {
                status = ((Short) statusStack.pop()).shortValue();
            }
        } else if (qName.equalsIgnoreCase(HELP_URL)) {
            switch (status) {
            case IN_ITEM:
            	String localUrl = getLocalGuidelineURL(curValue);
            	if (localUrl!=null) curItem.setUrl(localUrl);
            	else	curItem.setUrl(curValue);
                break;
            default:
            }
            ;
        } else if (qName.equalsIgnoreCase(DESCRIPTION)) {
            switch (status) {
            case IN_LEVEL:
                descriptionsV.add(curValue);
                break;
            case IN_GUIDELINE:
                description = curValue;
                break;
            default:
            }
            ;

        } else if (qName.equalsIgnoreCase(CATEGORY)) {
            switch (status) {
            case IN_LEVEL:
                categoriesV.add(curValue);
                break;
            case IN_GUIDELINE:
                category = curValue;
                break;
            default:
            }
            ;
        } else if (qName.equalsIgnoreCase(GUIDELINE)) {

        } else if (qName.equalsIgnoreCase(MIMETYPES)) {
            if (!statusStack.isEmpty()) {
                status = ((Short) statusStack.pop()).shortValue();
            }
        } else if (qName.equalsIgnoreCase(ITEMS)) {
            if (!statusStack.isEmpty()) {
                status = ((Short) statusStack.pop()).shortValue();
            }
        } else if (qName.equalsIgnoreCase(LEVELS)) {
            if (!statusStack.isEmpty()) {
                status = ((Short) statusStack.pop()).shortValue();
            }
        } else if (qName.equalsIgnoreCase(MIMETYPE)) {
            switch (status) {
            case IN_MIMETYPES:
                mimeV.add(curValue);
                break;
            default:
            }
            ;
        } else if (qName.equalsIgnoreCase(LEVEL)) {
            if (!statusStack.isEmpty()) {
                status = ((Short) statusStack.pop()).shortValue();
            }
            if (levelsV.size() > descriptionsV.size()) {
                descriptionsV.add("");
            }
            if (levelsV.size() > categoriesV.size()) {
                categoriesV.add("");
            }

        } else {
            System.out.println("unknown element(end): " + qName);
        }
    }

    /**
     * 
     */
    public void startDocument() {
    }

    /**
     * 
     */
    public void startElement(String uri, String localName, String qName, Attributes attributes) {

        curValue = "";
        if (qName.equalsIgnoreCase(GITEM)) {
            statusStack.push(new Short(status));
            status = IN_ITEM;
            curItem = new GuidelineItem(guidelineName);
            curItem.setLevel(getAttribute(attributes, LEVEL));
            curItem.setId(getAttribute(attributes, ID));
        } else if (qName.equalsIgnoreCase(HELP_URL)) {

        } else if (qName.equalsIgnoreCase(GUIDELINE)) {
            guidelineName = getAttribute(attributes, NAME);
            getGuidelineOrder(attributes);
        } else if (qName.equalsIgnoreCase(MIMETYPES)) {
            statusStack.push(new Short(status));
            status = IN_MIMETYPES;
        } else if (qName.equalsIgnoreCase(LEVELS)) {
            statusStack.push(new Short(status));
            status = IN_LEVELS;
        } else if (qName.equalsIgnoreCase(LEVEL)) {
            statusStack.push(new Short(status));
            status = IN_LEVEL;
            levelsV.add(getAttribute(attributes, ID));
        } else if (qName.equalsIgnoreCase(ITEMS)) {
            statusStack.push(new Short(status));
            status = IN_ITEMS;
        } else {

        }

    }

    public boolean isSucceed() {
        return succeed;
    }

    private String getAttribute(Attributes attr, String target) {
        String result = attr.getValue(target);
        if (result == null) {
            result = "";
        }
        return result;
    }

    private void getGuidelineOrder(Attributes attr) {
        String idS = attr.getValue(ORDER);
        order = Integer.MAX_VALUE;

        if (guidelineName != null) {
            try {
                order = Integer.parseInt(idS);
            } catch (Exception e) {
            }
        }
    }

}