package com.jclark.xsl.conv;

import java.net.URL;
import java.util.Hashtable;

public class NumberListFormat implements Cloneable {

  static private NumberFormat defaultFormat = new DecimalNumberFormat('0', 1);
  static private Hashtable formatTokenHandlerTable = new Hashtable();

  static {
    NumberFormat format = new AlphabetNumberFormat("abcdefghijklmnopqrstuvwxyz");
    AlphabetFormatTokenHandler handler = new AlphabetFormatTokenHandler(format);
    formatTokenHandlerTable.put("a", handler);
    format = new AlphabetNumberFormat("ABCDEFGHIJKLMNOPQRSTUVWXYZ");
    handler = new AlphabetFormatTokenHandler(format);
    formatTokenHandlerTable.put("A", handler);
    formatTokenHandlerTable.put("i", new RomanNumberFormat("mdclxvi"));
    formatTokenHandlerTable.put("I", new RomanNumberFormat("MDCLXVI"));
  }

  private NumberFormat[] formats = null;
  private String[] formatTokens = new String[] { "1" };
  private String prefix = "";
  private String suffix = "";
  // i-th element is separator between i-th and i+1-th number
  private String[] separators = new String[] { "." };
  private int groupingSize = 0;
  private String groupingSeparator = null;
  private String lang = null;
  private String letterValue = null;

  public static
  void setFormatTokenHandler(String formatToken, FormatTokenHandler handler) {
    formatTokenHandlerTable.put(formatToken, handler);
  }

  public void setFormat(String format) {
    formats = null;
    int n = 0;
    for (int i = 0; i < format.length(); i++) {
      if (isAlnum(format.charAt(i))
          && (i == 0 || !isAlnum(format.charAt(i - 1))))
	n++;
    }
    if (n == 0) {
      formatTokens = new String[1];
      formatTokens[0] = "1";
      prefix = "";
    }
    else
      formatTokens = new String[n];
    if (n <= 1) {
      separators = new String[1];
      separators[0] = ".";
    }
    else
      separators = new String[n - 1];
    int fi = 0;
    for (int i = 0; i < n; i++) {
      int sepStart = fi;
      while (!isAlnum(format.charAt(fi)))
	fi++;
      if (i == 0)
	prefix = format.substring(0, fi);
      else
	separators[i - 1] = format.substring(sepStart, fi);
      int numberStart = fi++;
      while (fi < format.length() && isAlnum(format.charAt(fi)))
	fi++;
      formatTokens[i] = format.substring(numberStart, fi);
    }
    suffix = format.substring(fi);
  }

  static private boolean isAlnum(char c) {
    switch (Character.getType(c)) {
    case Character.UPPERCASE_LETTER:
    case Character.LOWERCASE_LETTER:
    case Character.TITLECASE_LETTER:
    case Character.MODIFIER_LETTER:
    case Character.OTHER_LETTER:
    case Character.DECIMAL_DIGIT_NUMBER:
    case Character.LETTER_NUMBER:
    case Character.OTHER_NUMBER:
      return true;
    }
    return false;
  }

  public void setLang(String lang) {
    formats = null;
    this.lang = lang;
  }

  public void setLetterValue(String letterValue) {
    this.letterValue = letterValue;
  }

  public void setGroupingSeparator(String sep) {
    if (sep == null || sep.length() == 0)
      groupingSeparator = null;
    else
      groupingSeparator = sep;
  }

  public void setGroupingSize(int n) {
    groupingSize = n;
  }

  public String getPrefix(int i) {
    if (i == 0)
      return prefix;
    i -= 1;
    if (i < separators.length)
      return separators[i];
    return separators[separators.length - 1];
  }

  public String formatNumber(int i, int n) {
    if (n < 0)
      throw new IllegalArgumentException("cannot format negative number");
    return group(getFormat(i).format(n));
  }

  public String getSuffix() {
    return suffix;
  }

  private NumberFormat getFormat(int i) {
    if (formats == null)
      formats = new NumberFormat[formatTokens.length];
    if (i >= formats.length)
      i = formats.length - 1;
    if (formats[i] == null)
      formats[i] = findFormat(formatTokens[i]);
    return formats[i];
  }

  private NumberFormat findFormat(String formatToken) {
    NumberFormat f = findDecimalFormat(formatToken);
    if (f != null)
      return f;
    FormatTokenHandler handler = (FormatTokenHandler)formatTokenHandlerTable.get(formatToken);
    if (handler != null) {
      f = handler.getFormat(lang, letterValue);
      if (f != null)
	return f;
    }
    return defaultFormat;
  }

  private NumberFormat findDecimalFormat(String format) {
    char digitOne = format.charAt(format.length() - 1);
    if (!Character.isDigit(digitOne) || Character.digit(digitOne, 10) != 1)
      return null;
    for (int i = 0; i < format.length() - 1; i++)
      if (format.charAt(i) + 1 != digitOne)
        return null;
    return new DecimalNumberFormat((char)(digitOne - 1), format.length());
  }

  private String group(String number) {
    if (groupingSeparator == null || groupingSize <= 0 || number.length() <= groupingSize)
      return number;
    char buf[] = new char[number.length() + ((number.length() - 1)/groupingSize) * groupingSeparator.length()];
    int j = 0;
    for (int i = 0; i < number.length(); i++) {
      if (i > 0 && (number.length() - i) % groupingSize == 0) {
	for (int k = 0; k < groupingSeparator.length(); k++)
	  buf[j++] = groupingSeparator.charAt(k);
      }
      buf[j++] = number.charAt(i);
    }
    return new String(buf);
  }

  public Object clone() {
    try {
      return super.clone();
    } catch (CloneNotSupportedException e) { 
      throw new InternalError();
    }
  }

}