/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the  "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id$
 */

package org.apache.xalan.xsltc.dom;

import java.util.Vector;

import org.apache.xalan.xsltc.DOM;
import org.apache.xalan.xsltc.Translet;
import org.apache.xml.dtm.DTM;
import org.apache.xml.dtm.DTMAxisIterator;
import org.apache.xml.dtm.Axis;

/**
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 * @author Morten Jorgensen
 */
public abstract class NodeCounter {
    public static final int END = DTM.NULL;

    protected int _node = END;
    protected int _nodeType = DOM.FIRST_TYPE - 1;
    protected double _value = Integer.MIN_VALUE;

    public final DOM          _document;
    public final DTMAxisIterator _iterator;
    public final Translet     _translet;

    protected String _format;
    protected String _lang;
    protected String _letterValue;
    protected String _groupSep;
    protected int    _groupSize;

    private boolean _separFirst = true;
    private boolean _separLast = false;
    private Vector _separToks = new Vector();
    private Vector _formatToks = new Vector();
    private int _nSepars  = 0;
    private int _nFormats = 0;

    private final static String[] Thousands = 
        {"", "m", "mm", "mmm" };
    private final static String[] Hundreds = 
    {"", "c", "cc", "ccc", "cd", "d", "dc", "dcc", "dccc", "cm"};
    private final static String[] Tens = 
    {"", "x", "xx", "xxx", "xl", "l", "lx", "lxx", "lxxx", "xc"};
    private final static String[] Ones = 
    {"", "i", "ii", "iii", "iv", "v", "vi", "vii", "viii", "ix"};
  
  private StringBuffer _tempBuffer = new StringBuffer();
    
    protected NodeCounter(Translet translet,
              DOM document, DTMAxisIterator iterator) {
    _translet = translet;
    _document = document;
    _iterator = iterator;
    }

    /** 
     * Set the start node for this counter. The same <tt>NodeCounter</tt>
     * object can be used multiple times by resetting the starting node.
     */
    abstract public NodeCounter setStartNode(int node);

    /** 
     * If the user specified a value attribute, use this instead of 
     * counting nodes.
     */
    public NodeCounter setValue(double value) {
    _value = value;
    return this;
    }

    /**
     * Sets formatting fields before calling formatNumbers().
     */
    protected void setFormatting(String format, String lang, String letterValue,
                 String groupSep, String groupSize) {
    _lang = lang;
    _groupSep = groupSep;
    _letterValue = letterValue;

    try {
        _groupSize = Integer.parseInt(groupSize);
    }
    catch (NumberFormatException e) {
       _groupSize = 0;
    }
    setTokens(format);

 }
  
  // format == null assumed here 
 private final void setTokens(final String format){
     if( (_format!=null) &&(format.equals(_format)) ){// has already been set
        return;
     }
     _format = format;
     // reset
     final int length = _format.length();
     boolean isFirst = true;
     _separFirst = true;
     _separLast = false;
     _nSepars  = 0;
     _nFormats = 0;
     _separToks.clear() ;
     _formatToks.clear();

         /* 
          * Tokenize the format string into alphanumeric and non-alphanumeric
          * tokens as described in M. Kay page 241.
          */
         for (int j = 0, i = 0; i < length;) {
                 char c = format.charAt(i);
                 for (j = i; Character.isLetterOrDigit(c);) {
                     if (++i == length) break;
             c = format.charAt(i);
                 }
                 if (i > j) {
                     if (isFirst) {
                         _separToks.addElement(".");
                         isFirst = _separFirst = false;
                     }
                     _formatToks.addElement(format.substring(j, i));
                 }

                 if (i == length) break;

                 c = format.charAt(i);
                 for (j = i; !Character.isLetterOrDigit(c);) {
                     if (++i == length) break;
                     c = format.charAt(i);
                     isFirst = false;
                 }
                 if (i > j) {
                     _separToks.addElement(format.substring(j, i));
                 }
             }

         _nSepars = _separToks.size();
         _nFormats = _formatToks.size(); 
         if (_nSepars > _nFormats) _separLast = true;

         if (_separFirst) _nSepars--;
         if (_separLast) _nSepars--;
         if (_nSepars == 0) {
             _separToks.insertElementAt(".", 1);
             _nSepars++;
         }
         if (_separFirst) _nSepars ++;
 
 }
    /**
     * Sets formatting fields to their default values.
     */
    public NodeCounter setDefaultFormatting() {
    setFormatting("1", "en", "alphabetic", null, null);
    return this;
    }

    /**
     * Returns the position of <tt>node</tt> according to the level and 
     * the from and count patterns.
     */
    abstract public String getCounter();

    /**
     * Returns the position of <tt>node</tt> according to the level and 
     * the from and count patterns. This position is converted into a
     * string based on the arguments passed.
     */
    public String getCounter(String format, String lang, String letterValue,
                String groupSep, String groupSize) {
    setFormatting(format, lang, letterValue, groupSep, groupSize);
    return getCounter();
    }

    /**
     * Returns true if <tt>node</tt> matches the count pattern. By
     * default a node matches the count patterns if it is of the 
     * same type as the starting node.
     */
    public boolean matchesCount(int node) {
    return _nodeType == _document.getExpandedTypeID(node);
    }

    /**
     * Returns true if <tt>node</tt> matches the from pattern. By default, 
     * no node matches the from pattern.
     */
    public boolean matchesFrom(int node) {
    return false;
    }

    /**
     * Format a single value according to the format parameters.
     */
    protected String formatNumbers(int value) {
    return formatNumbers(new int[] { value });
    }

    /**
     * Format a sequence of values according to the format paramaters
     * set by calling setFormatting().
     */
    protected String formatNumbers(int[] values) {
    final int nValues = values.length;
    final int length = _format.length();

    boolean isEmpty = true;
    for (int i = 0; i < nValues; i++)
        if (values[i] != Integer.MIN_VALUE)
        isEmpty = false;
    if (isEmpty) return("");

    // Format the output string using the values array and the fmt. tokens
    boolean isFirst = true;
    int t = 0, n = 0, s = 1;
  _tempBuffer.setLength(0);
    final StringBuffer buffer = _tempBuffer;

    // Append separation token before first digit/letter/numeral
    if (_separFirst) buffer.append((String)_separToks.elementAt(0));

    // Append next digit/letter/numeral and separation token
    while (n < nValues) {
        final int value = values[n];
        if (value != Integer.MIN_VALUE) {
        if (!isFirst) buffer.append((String) _separToks.elementAt(s++));
        formatValue(value, (String)_formatToks.elementAt(t++), buffer);
        if (t == _nFormats) t--;
        if (s >= _nSepars) s--;
        isFirst = false;
        }
        n++;
    }

    // Append separation token after last digit/letter/numeral
    if (_separLast) buffer.append((String)_separToks.lastElement());
    return buffer.toString();
    }

    /**
     * Format a single value based on the appropriate formatting token. 
     * This method is based on saxon (Michael Kay) and only implements
     * lang="en".
     */
    private void formatValue(int value, String format, StringBuffer buffer) {
        char c = format.charAt(0);

        if (Character.isDigit(c)) {
            char zero = (char)(c - Character.getNumericValue(c));

            StringBuffer temp = buffer;
            if (_groupSize > 0) {
                temp = new StringBuffer();
            }
            String s = "";
            int n = value;
            while (n > 0) {
                s = (char) ((int) zero + (n % 10)) + s;
                n = n / 10;
            }
                
            for (int i = 0; i < format.length() - s.length(); i++) {
                temp.append(zero);
            }
            temp.append(s);
            
            if (_groupSize > 0) {
                for (int i = 0; i < temp.length(); i++) {
                    if (i != 0 && ((temp.length() - i) % _groupSize) == 0) {
                        buffer.append(_groupSep);
                    }
                    buffer.append(temp.charAt(i));
                }
            }
        } 
    else if (c == 'i' && !_letterValue.equals("alphabetic")) {
            buffer.append(romanValue(value));
        } 
    else if (c == 'I' && !_letterValue.equals("alphabetic")) {
            buffer.append(romanValue(value).toUpperCase());
        } 
    else {
        int min = (int) c;
        int max = (int) c;

        // Special case for Greek alphabet 
        if (c >= 0x3b1 && c <= 0x3c9) {
        max = 0x3c9;    // omega
        }
        else {
        // General case: search for end of group
        while (Character.isLetterOrDigit((char) (max + 1))) {
            max++;
        }
        }
            buffer.append(alphaValue(value, min, max));
        }
    }

    private String alphaValue(int value, int min, int max) {
        if (value <= 0) {
        return "" + value;
    }

        int range = max - min + 1;
        char last = (char)(((value-1) % range) + min);
        if (value > range) {
            return alphaValue((value-1) / range, min, max) + last;
        } 
    else {
            return "" + last;
        }
    }

    private String romanValue(int n) {
        if (n <= 0 || n > 4000) {
        return "" + n;
    }
        return
        Thousands[n / 1000] +
        Hundreds[(n / 100) % 10] +
        Tens[(n/10) % 10] +
        Ones[n % 10];
    }

}