// +---------------------------------------------------------------------------+
// | FCS -- Fast,Compatible & Simple OOP PHP Framework                         |
// | FCS JS 基类库                                                             |
// +---------------------------------------------------------------------------+
// | Copyright (c) 2005-2006 liu21st.com.  All rights reserved.                |
// | Website: http://www.fcs.org.cn/                                           |
// | Author : Liu21st 流年 <liu21st@gmail.com>                                 |
// +---------------------------------------------------------------------------+
// | 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.                                          |
// +---------------------------------------------------------------------------+

/**
 +------------------------------------------------------------------------------
 * 货币处理类
 +------------------------------------------------------------------------------
 * @package    Form
 * @link       http://www.fcs.org.cn
 * @copyright  Copyright (c) 2005-2006 liu21st.com.  All rights reserved. 
 * @author     liu21st <liu21st@gmail.com>
 * @version    $Id$
 +------------------------------------------------------------------------------
 */

function convertCurrency(currencyDigits) {
// Constants:
 var MAXIMUM_NUMBER = 99999999999.99;
 // Predefine the radix characters and currency symbols for output:
 var CN_ZERO = "零";
 var CN_ONE = "壹";
 var CN_TWO = "贰";
 var CN_THREE = "叁";
 var CN_FOUR = "肆";
 var CN_FIVE = "伍";
 var CN_SIX = "陆";
 var CN_SEVEN = "柒";
 var CN_EIGHT = "捌";
 var CN_NINE = "玖";
 var CN_TEN = "拾";
 var CN_HUNDRED = "佰";
 var CN_THOUSAND = "仟";
 var CN_TEN_THOUSAND = "万";
 var CN_HUNDRED_MILLION = "亿";
 var CN_SYMBOL = "人民币";
 var CN_DOLLAR = "元";
 var CN_TEN_CENT = "角";
 var CN_CENT = "分";
 var CN_INTEGER = "整";
 
// Variables:
 var integral; // Represent integral part of digit number.
 var decimal; // Represent decimal part of digit number.
 var outputCharacters; // The output result.
 var parts;
 var digits, radices, bigRadices, decimals;
 var zeroCount;
 var i, p, d;
 var quotient, modulus;
 
// Validate input string:
 currencyDigits = currencyDigits.toString();
 if (currencyDigits == "") {
  alert("Empty input!");
  return "";
 }
 if (currencyDigits.match(/[^,.\d]/) != null) {
  alert("Invalid characters in the input string!");
  return "";
 }
 if ((currencyDigits).match(/^((\d{1,3}(,\d{3})*(.((\d{3},)*\d{1,3}))?)|(\d+(.\d+)?))$/) == null) {
  alert("Illegal format of digit number!");
  return "";
 }
 
// Normalize the format of input digits:
 currencyDigits = currencyDigits.replace(/,/g, ""); // Remove comma delimiters.
 currencyDigits = currencyDigits.replace(/^0+/, ""); // Trim zeros at the beginning.
 // Assert the number is not greater than the maximum number.
 if (Number(currencyDigits) > MAXIMUM_NUMBER) {
  alert("Too large a number to convert!");
  return "";
 }
 
// Process the coversion from currency digits to characters:
 // Separate integral and decimal parts before processing coversion:
 parts = currencyDigits.split(".");
 if (parts.length > 1) {
  integral = parts[0];
  decimal = parts[1];
  // Cut down redundant decimal digits that are after the second.
  decimal = decimal.substr(0, 2);
 }
 else {
  integral = parts[0];
  decimal = "";
 }
 // Prepare the characters corresponding to the digits:
 digits = new Array(CN_ZERO, CN_ONE, CN_TWO, CN_THREE, CN_FOUR, CN_FIVE, CN_SIX, CN_SEVEN, CN_EIGHT, CN_NINE);
 radices = new Array("", CN_TEN, CN_HUNDRED, CN_THOUSAND);
 bigRadices = new Array("", CN_TEN_THOUSAND, CN_HUNDRED_MILLION);
 decimals = new Array(CN_TEN_CENT, CN_CENT);
 // Start processing:
 outputCharacters = "";
 // Process integral part if it is larger than 0:
 if (Number(integral) > 0) {
  zeroCount = 0;
  for (i = 0; i < integral.length; i++) {
   p = integral.length - i - 1;
   d = integral.substr(i, 1);
   quotient = p / 4;
   modulus = p % 4;
   if (d == "0") {
    zeroCount++;
   }
   else {
    if (zeroCount > 0)
    {
     outputCharacters += digits[0];
    }
    zeroCount = 0;
    outputCharacters += digits[Number(d)] + radices[modulus];
   }
   if (modulus == 0 && zeroCount < 4) {
    outputCharacters += bigRadices[quotient];
   }
  }
  outputCharacters += CN_DOLLAR;
 }
 // Process decimal part if there is:
 if (decimal != "") {
  for (i = 0; i < decimal.length; i++) {
   d = decimal.substr(i, 1);
   if (d != "0") {
    outputCharacters += digits[Number(d)] + decimals[i];
   }
  }
 }
 // Confirm and return the final output string:
 if (outputCharacters == "") {
  outputCharacters = CN_ZERO + CN_DOLLAR;
 }
 if (decimal == "") {
  outputCharacters += CN_INTEGER;
 }
 outputCharacters = CN_SYMBOL + outputCharacters;
 return outputCharacters;
}