package com.rc.core.util;

public class EscapeUnescape {

    public static String escape(String src) {
        int i;
        char j;
        StringBuffer tmp = new StringBuffer();
        tmp.ensureCapacity(src.length() * 6);

        for (i = 0; i < src.length(); i++) {

            j = src.charAt(i);

            if (Character.isDigit(j) || Character.isLowerCase(j) || Character.isUpperCase(j))
                tmp.append(j);
            else if (j < 256) {
                tmp.append("%");
                if (j < 16)
                    tmp.append("0");
                tmp.append(Integer.toString(j, 16));
            } else {
                tmp.append("%u");
                tmp.append(Integer.toString(j, 16));
            }
        }
        return tmp.toString();
    }

    public static String unescape(String src) {
        StringBuilder tmp = new StringBuilder();
        tmp.ensureCapacity(src.length());
        int lastPos = 0, pos = 0;
        char ch;
        while (lastPos < src.length()) {
            pos = src.indexOf("%", lastPos);
            if (pos == lastPos) {
                if (src.charAt(pos + 1) == 'u') {
                    ch = (char) Integer.parseInt(src.substring(pos + 2, pos + 6), 16);
                    tmp.append(ch);
                    lastPos = pos + 6;
                } else {
                    ch = (char) Integer.parseInt(src.substring(pos + 1, pos + 3), 16);
                    tmp.append(ch);
                    lastPos = pos + 3;
                }
            } else {
                if (pos == -1) {
                    tmp.append(src.substring(lastPos));
                    lastPos = src.length();
                } else {
                    tmp.append(src.substring(lastPos, pos));
                    lastPos = pos;
                }
            }
        }
        return tmp.toString();
    }

//    public static void main(String[] args) {
//        String tmp = "~!@#$%^&*()_+|\\=-,./?><;'][{}\"";
//        System.out.println("testing escape : " + tmp);
//        tmp = escape(tmp);
//        System.out.println(tmp);
//        System.out.println("testing unescape :" + tmp);
//        System.out.println(unescape(tmp));
//    }
}