/*
 * XMLParseUtil.java
 *
 *
 *  The Salamander Project - 2D and 3D graphics libraries in Java
 *  Copyright (C) 2004 Mark McKay
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library 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
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 *  Mark McKay can be contacted at mark@kitfox.com.  Salamander and other
 *  projects can be found at http://www.kitfox.com
 *
 * Created on February 18, 2004, 1:49 PM
 */

package com.kitfox.svg.xml;

import org.w3c.dom.*;
import java.awt.*;
import java.net.*;
import java.util.*;
import java.util.regex.*;
import java.lang.reflect.*;

/**
 * @author Mark McKay
 * @author <a href="mailto:mark@kitfox.com">Mark McKay</a>
 */
public class XMLParseUtil
{
    static final Matcher fpMatch = Pattern.compile("([-+]?((\\d*\\.\\d+)|(\\d+))([eE][+-]?\\d+)?)(\\%|in|cm|mm|pt|pc|px|em|ex)?").matcher("");
    static final Matcher intMatch = Pattern.compile("[-+]?\\d+").matcher("");

    /** Creates a new instance of XMLParseUtil */
    private XMLParseUtil()
    {
    }

    /**
     * Scans the tag's children and returns the first text element found
     */
    public static String getTagText(Element ele)
    {
        NodeList nl = ele.getChildNodes();
        int size = nl.getLength();

        Node node = null;
        int i = 0;
        for (; i < size; i++)
        {
            node = nl.item(i);
            if (node instanceof Text) break;
        }
        if (i == size || node == null) return null;

        return ((Text)node).getData();
    }

    /**
     * Returns the first node that is a direct child of root with the coresponding
     * name.  Does not search children of children.
     */
    public static Element getFirstChild(Element root, String name)
    {
        NodeList nl = root.getChildNodes();
        int size = nl.getLength();
        for (int i = 0; i < size; i++)
        {
            Node node = nl.item(i);
            if (!(node instanceof Element)) continue;
            Element ele = (Element)node;
            if (ele.getTagName().equals(name)) return ele;
        }

        return null;
    }

    public static String[] parseStringList(String list)
    {
//        final Pattern patWs = Pattern.compile("\\s+");
        final Matcher matchWs = Pattern.compile("[^\\s]+").matcher("");
        matchWs.reset(list);

        LinkedList matchList = new LinkedList();
        while (matchWs.find())
        {
            matchList.add(matchWs.group());
        }

        String[] retArr = new String[matchList.size()];
        return (String[])matchList.toArray(retArr);
    }

    public static boolean isDouble(String val)
    {
        fpMatch.reset(val);
        return fpMatch.matches();
    }
    
    public static double parseDouble(String val)
    {
        /*
        if (val == null) return 0.0;

        double retVal = 0.0;
        try
        { retVal = Double.parseDouble(val); }
        catch (Exception e)
        {}
        return retVal;
         */
        return findDouble(val);
    }

    /**
     * Searches the given string for the first floating point number it contains,
     * parses and returns it.
     */
    public synchronized static double findDouble(String val)
    {
        if (val == null) return 0;

        fpMatch.reset(val);
        try
        {
            if (!fpMatch.find()) return 0;
        }
        catch (StringIndexOutOfBoundsException e)
        {
            System.err.println("XMLParseUtil: regex parse problem: '" + val + "'");
            e.printStackTrace();
        }

        val = fpMatch.group(1);
        //System.err.println("Parsing " + val);

        double retVal = 0;
        try
        { 
            retVal = Double.parseDouble(val); 
            
            float pixPerInch;
            try {
                pixPerInch = (float)Toolkit.getDefaultToolkit().getScreenResolution();
            }
            catch (NoClassDefFoundError err)
            {
                //Default value for headless X servers
                pixPerInch = 72;
            }
            final float inchesPerCm = .3936f;
            final String units = fpMatch.group(6);
            
            if ("%".equals(units)) retVal /= 100;
            else if ("in".equals(units))
            {
                retVal *= pixPerInch;
            }
            else if ("cm".equals(units))
            {
                retVal *= inchesPerCm * pixPerInch;
            }
            else if ("mm".equals(units))
            {
                retVal *= inchesPerCm * pixPerInch * .1f;
            }
            else if ("pt".equals(units))
            {
                retVal *= (1f / 72f) * pixPerInch;
            }
            else if ("pc".equals(units))
            {
                retVal *= (1f / 6f) * pixPerInch;
            }
        }
        catch (Exception e)
        {}
        return retVal;
    }

    /**
     * Scans an input string for double values.  For each value found, places
     * in a list.  This method regards any characters not part of a floating
     * point value to be seperators.  Thus this will parse whitespace seperated,
     * comma seperated, and many other separation schemes correctly.
     */
    public synchronized static double[] parseDoubleList(String list)
    {
        if (list == null) return null;

        fpMatch.reset(list);

        LinkedList doubList = new LinkedList();
        while (fpMatch.find())
        {
            String val = fpMatch.group(1);
            doubList.add(Double.valueOf(val));
        }

        double[] retArr = new double[doubList.size()];
        Iterator it = doubList.iterator();
        int idx = 0;
        while (it.hasNext())
        {
            retArr[idx++] = ((Double)it.next()).doubleValue();
        }

        return retArr;
    }

    public static float parseFloat(String val)
    {
        /*
        if (val == null) return 0f;

        float retVal = 0f;
        try
        { retVal = Float.parseFloat(val); }
        catch (Exception e)
        {}
        return retVal;
         */
        return findFloat(val);
    }

    /**
     * Searches the given string for the first floating point number it contains,
     * parses and returns it.
     */
    public synchronized static float findFloat(String val)
    {
        if (val == null) return 0f;

        fpMatch.reset(val);
        if (!fpMatch.find()) return 0f;

        val = fpMatch.group(1);
        //System.err.println("Parsing " + val);

        float retVal = 0f;
        try
        {
            retVal = Float.parseFloat(val);
            String units = fpMatch.group(6);
            if ("%".equals(units)) retVal /= 100;
        }
        catch (Exception e)
        {}
        return retVal;
    }

    public synchronized static float[] parseFloatList(String list)
    {
        if (list == null) return null;

        fpMatch.reset(list);

        LinkedList floatList = new LinkedList();
        while (fpMatch.find())
        {
            String val = fpMatch.group(1);
            floatList.add(Float.valueOf(val));
        }

        float[] retArr = new float[floatList.size()];
        Iterator it = floatList.iterator();
        int idx = 0;
        while (it.hasNext())
        {
            retArr[idx++] = ((Float)it.next()).floatValue();
        }

        return retArr;
    }

    public static int parseInt(String val)
    {
        if (val == null) return 0;

        int retVal = 0;
        try
        { retVal = Integer.parseInt(val); }
        catch (Exception e)
        {}
        return retVal;
    }

    /**
     * Searches the given string for the first integer point number it contains,
     * parses and returns it.
     */
    public static int findInt(String val)
    {
        if (val == null) return 0;

        intMatch.reset(val);
        if (!intMatch.find()) return 0;

        val = intMatch.group();
        //System.err.println("Parsing " + val);

        int retVal = 0;
        try
        { retVal = Integer.parseInt(val); }
        catch (Exception e)
        {}
        return retVal;
    }

    public static int[] parseIntList(String list)
    {
        if (list == null) return null;

        intMatch.reset(list);

        LinkedList intList = new LinkedList();
        while (intMatch.find())
        {
            String val = intMatch.group();
            intList.add(Integer.valueOf(val));
        }

        int[] retArr = new int[intList.size()];
        Iterator it = intList.iterator();
        int idx = 0;
        while (it.hasNext())
        {
            retArr[idx++] = ((Integer)it.next()).intValue();
        }

        return retArr;
    }
/*
    public static int parseHex(String val)
    {
        int retVal = 0;
        
        for (int i = 0; i < val.length(); i++)
        {
            retVal <<= 4;
            
            char ch = val.charAt(i);
            if (ch >= '0' && ch <= '9')
            {
                retVal |= ch - '0';
            }
            else if (ch >= 'a' && ch <= 'z')
            {
                retVal |= ch - 'a' + 10;
            }
            else if (ch >= 'A' && ch <= 'Z')
            {
                retVal |= ch - 'A' + 10;
            }
            else throw new RuntimeException();
        }
        
        return retVal;
    }
*/
    /**
     * The input string represents a ratio.  Can either be specified as a
     * double number on the range of [0.0 1.0] or as a percentage [0% 100%]
     */
    public static double parseRatio(String val)
    {
        if (val == null || val.equals("")) return 0.0;

        if (val.charAt(val.length() - 1) == '%')
        {
            parseDouble(val.substring(0, val.length() - 1));
        }
        return parseDouble(val);
    }

    public static NumberWithUnits parseNumberWithUnits(String val)
    {
        if (val == null) return null;

        return new NumberWithUnits(val);
    }
/*
    public static Color parseColor(String val)
    {
        Color retVal = null;

        if (val.charAt(0) == '#')
        {
            String hexStrn = val.substring(1);
            
            if (hexStrn.length() == 3)
            {
                hexStrn = "" + hexStrn.charAt(0) + hexStrn.charAt(0) + hexStrn.charAt(1) + hexStrn.charAt(1) + hexStrn.charAt(2) + hexStrn.charAt(2);
            }
            int hexVal = parseHex(hexStrn);

            retVal = new Color(hexVal);
        }
        else
        {
            final Matcher rgbMatch = Pattern.compile("rgb\\((\\d+),(\\d+),(\\d+)\\)", Pattern.CASE_INSENSITIVE).matcher("");

            rgbMatch.reset(val);
            if (rgbMatch.matches())
            {
                int r = Integer.parseInt(rgbMatch.group(1));
                int g = Integer.parseInt(rgbMatch.group(2));
                int b = Integer.parseInt(rgbMatch.group(3));
                retVal = new Color(r, g, b);
            }
            else
            {
                Color lookupCol = ColorTable.instance().lookupColor(val);
                if (lookupCol != null) retVal = lookupCol;
            }
        }

        return retVal;
    }
*/
    /**
     * Parses the given attribute of this tag and returns it as a String.
     */
    public static String getAttribString(Element ele, String name)
    {
        return ele.getAttribute(name);
    }

    /**
     * Parses the given attribute of this tag and returns it as an int.
     */
    public static int getAttribInt(Element ele, String name)
    {
        String sval = ele.getAttribute(name);
        int val = 0;
        try { val = Integer.parseInt(sval); } catch (Exception e) {}

        return val;
    }

    /**
     * Parses the given attribute of this tag as a hexadecimal encoded string and
     * returns it as an int
     */
    public static int getAttribIntHex(Element ele, String name)
    {
        String sval = ele.getAttribute(name);
        int val = 0;
        try { val = Integer.parseInt(sval, 16); } catch (Exception e) {}

        return val;
    }

    /**
     * Parses the given attribute of this tag and returns it as a float
     */
    public static float getAttribFloat(Element ele, String name)
    {
        String sval = ele.getAttribute(name);
        float val = 0.0f;
        try { val = Float.parseFloat(sval); } catch (Exception e) {}

        return val;
    }

    /**
     * Parses the given attribute of this tag and returns it as a double.
     */
    public static double getAttribDouble(Element ele, String name)
    {
        String sval = ele.getAttribute(name);
        double val = 0.0;
        try { val = Double.parseDouble(sval); } catch (Exception e) {}

        return val;
    }

    /**
     * Parses the given attribute of this tag and returns it as a boolean.
     * Essentially compares the lower case textual value to the string "true"
     */
    public static boolean getAttribBoolean(Element ele, String name)
    {
        String sval = ele.getAttribute(name);

        return sval.toLowerCase().equals("true");
    }

    public static URL getAttribURL(Element ele, String name, URL docRoot)
    {
        String sval = ele.getAttribute(name);

        URL url;
        try
        {
            return new URL(docRoot, sval);
        }
        catch (Exception e)
        {
            return null;
        }
    }

    /**
     * Returns the first ReadableXMLElement with the given name
     */
    public static ReadableXMLElement getElement(Class classType, Element root, String name, URL docRoot)
    {
        if (root == null) return null;

        //Do not process if not a LoadableObject
        if (!ReadableXMLElement.class.isAssignableFrom(classType))
        {
            return null;
        }

        NodeList nl = root.getChildNodes();
        int size = nl.getLength();
        for (int i = 0; i < size; i++)
        {
            Node node = nl.item(i);
            if (!(node instanceof Element)) continue;
            Element ele = (Element)node;
            if (!ele.getTagName().equals(name)) continue;

            ReadableXMLElement newObj = null;
            try { newObj = (ReadableXMLElement)classType.newInstance(); }
            catch (Exception e) { e.printStackTrace(); continue; }
            newObj.read(ele, docRoot);

            if (newObj == null) continue;

            return newObj;
        }

        return null;
    }

    /**
     * Returns a HashMap of nodes that are children of root.  All nodes will
     * be of class classType and have a tag name of 'name'.  'key' is
     * an attribute of tag 'name' who's string value will be used as the key
     * in the HashMap
     */
    public static HashMap getElementHashMap(Class classType, Element root, String name, String key, URL docRoot)
    {
        if (root == null) return null;

        //Do not process if not a LoadableObject
        if (!ReadableXMLElement.class.isAssignableFrom(classType))
        {
            return null;
        }

        HashMap retMap = new HashMap();

/*
        Class[] params = {Element.class, URL.class};
        Method loadMethod = null;
        try { loadMethod = classType.getMethod("load", params); }
        catch (Exception e) { e.printStackTrace(); return null; }

 */
        NodeList nl = root.getChildNodes();
        int size = nl.getLength();
        for (int i = 0; i < size; i++)
        {
            Node node = nl.item(i);
            if (!(node instanceof Element)) continue;
            Element ele = (Element)node;
            if (!ele.getTagName().equals(name)) continue;

            ReadableXMLElement newObj = null;
            try { newObj = (ReadableXMLElement)classType.newInstance(); }
            catch (Exception e) { e.printStackTrace(); continue; }
            newObj.read(ele, docRoot);
/*
            Object[] args = {ele, source};
            Object obj = null;
            try { obj = loadMethod.invoke(null, args); }
            catch (Exception e) { e.printStackTrace(); }

 */
            if (newObj == null) continue;

            String keyVal = getAttribString(ele, key);
            retMap.put(keyVal, newObj);
        }

        return retMap;
    }

    public static HashSet getElementHashSet(Class classType, Element root, String name, URL docRoot)
    {
        if (root == null) return null;

        //Do not process if not a LoadableObject
        if (!ReadableXMLElement.class.isAssignableFrom(classType))
        {
            return null;
        }

        HashSet retSet = new HashSet();

        /*
        Class[] params = {Element.class, URL.class};
        Method loadMethod = null;
        try { loadMethod = classType.getMethod("load", params); }
        catch (Exception e) { e.printStackTrace(); return null; }
        */

        NodeList nl = root.getChildNodes();
        int size = nl.getLength();
        for (int i = 0; i < size; i++)
        {
            Node node = nl.item(i);
            if (!(node instanceof Element)) continue;
            Element ele = (Element)node;
            if (!ele.getTagName().equals(name)) continue;

            ReadableXMLElement newObj = null;
            try { newObj = (ReadableXMLElement)classType.newInstance(); }
            catch (Exception e) { e.printStackTrace(); continue; }
            newObj.read(ele, docRoot);
            /*
            Object[] args = {ele, source};
            Object obj = null;
            try { obj = loadMethod.invoke(null, args); }
            catch (Exception e) { e.printStackTrace(); }
             */

            if (newObj == null) continue;

            retSet.add(newObj);
        }

        return retSet;
    }


    public static LinkedList getElementLinkedList(Class classType, Element root, String name, URL docRoot)
    {
        if (root == null) return null;

        //Do not process if not a LoadableObject
        if (!ReadableXMLElement.class.isAssignableFrom(classType))
        {
            return null;
        }

        NodeList nl = root.getChildNodes();
        LinkedList elementCache = new LinkedList();
        int size = nl.getLength();
        for (int i = 0; i < size; i++)
        {
            Node node = nl.item(i);
            if (!(node instanceof Element)) continue;
            Element ele = (Element)node;
            if (!ele.getTagName().equals(name)) continue;

            ReadableXMLElement newObj = null;
            try { newObj = (ReadableXMLElement)classType.newInstance(); }
            catch (Exception e) { e.printStackTrace(); continue; }
            newObj.read(ele, docRoot);

            elementCache.addLast(newObj);
        }

        return elementCache;
    }

    public static Object[] getElementArray(Class classType, Element root, String name, URL docRoot)
    {
        if (root == null) return null;

        //Do not process if not a LoadableObject
        if (!ReadableXMLElement.class.isAssignableFrom(classType))
        {
            return null;
        }

        LinkedList elementCache = getElementLinkedList(classType, root, name, docRoot);

        Object[] retArr = (Object[])Array.newInstance(classType, elementCache.size());
        return elementCache.toArray(retArr);
    }

    /**
     * Takes a number of tags of name 'name' that are children of 'root', and
     * looks for attributes of 'attrib' on them.  Converts attributes to an
     * int and returns in an array.
     */
    public static int[] getElementArrayInt(Element root, String name, String attrib)
    {
        if (root == null) return null;

        NodeList nl = root.getChildNodes();
        LinkedList elementCache = new LinkedList();
        int size = nl.getLength();

        for (int i = 0; i < size; i++)
        {
            Node node = nl.item(i);
            if (!(node instanceof Element)) continue;
            Element ele = (Element)node;
            if (!ele.getTagName().equals(name)) continue;

            String valS = ele.getAttribute(attrib);
            int eleVal = 0;
            try { eleVal = Integer.parseInt(valS); }
            catch (Exception e) {}

            elementCache.addLast(new Integer(eleVal));
        }

        int[] retArr = new int[elementCache.size()];
        Iterator it = elementCache.iterator();
        int idx = 0;
        while (it.hasNext())
        {
            retArr[idx++] = ((Integer)it.next()).intValue();
        }

        return retArr;
    }

    /**
     * Takes a number of tags of name 'name' that are children of 'root', and
     * looks for attributes of 'attrib' on them.  Converts attributes to an
     * int and returns in an array.
     */
    public static String[] getElementArrayString(Element root, String name, String attrib)
    {
        if (root == null) return null;

        NodeList nl = root.getChildNodes();
        LinkedList elementCache = new LinkedList();
        int size = nl.getLength();

        for (int i = 0; i < size; i++)
        {
            Node node = nl.item(i);
            if (!(node instanceof Element)) continue;
            Element ele = (Element)node;
            if (!ele.getTagName().equals(name)) continue;

            String valS = ele.getAttribute(attrib);

            elementCache.addLast(valS);
        }

        String[] retArr = new String[elementCache.size()];
        Iterator it = elementCache.iterator();
        int idx = 0;
        while (it.hasNext())
        {
            retArr[idx++] = (String)it.next();
        }

        return retArr;
    }

    /**
     * Takes a CSS style string and retursn a hash of them.
     * @param styleString - A CSS formatted string of styles.  Eg,
     *     "font-size:12;fill:#d32c27;fill-rule:evenodd;stroke-width:1pt;"
     */
    public static HashMap parseStyle(String styleString) {
        return parseStyle(styleString, new HashMap());
    }

    /**
     * Takes a CSS style string and returns a hash of them.
     * @param styleString - A CSS formatted string of styles.  Eg,
     *     "font-size:12;fill:#d32c27;fill-rule:evenodd;stroke-width:1pt;"
     * @param map - A map to which these styles will be added
     */
    public static HashMap parseStyle(String styleString, HashMap map) {
        final Pattern patSemi = Pattern.compile(";");

        String[] styles = patSemi.split(styleString);

        for (int i = 0; i < styles.length; i++)
        {
            if (styles[i].length() == 0)
            {
                continue;
            }

            int colon = styles[i].indexOf(':');
            if (colon == -1)
            {
                continue;
            }

            String key = styles[i].substring(0, colon).trim();
            String value = styles[i].substring(colon + 1).trim();

            map.put(key, new StyleAttribute(key, value));
        }

        return map;
    }
}