/*
 * Copyright (c) 2012-2015 iWave Software LLC
 * All Rights Reserved
 */
package com.iwave.utility.ssh;

import org.apache.commons.lang.StringUtils;

public class IWaveStringUtils {

    /**
     * Removes the
     * 
     * @param stripChars characters from the beginning of
     * @param str , however, if
     *            it comes across a a white space character, as determined by {@link StringUtils#isWhitespace(String)} that is not part of
     *            the
     * @param stripChars before it gets to the end of
     * @param stripChars ,
     *            it will automatically skip it.
     * 
     *            Mainly used to remove string 1 from the beginning of string 2 where string 2 may have added line
     *            breaks etc.
     * 
     * @param str The string that @{stripChars} should be removed from
     * @param stripChars The string to remove from @{param str}
     * @return
     * @param str with
     * @param stripChars remove
     */
    public static String removeStartIgnoringWhiteSpace(String str, String stripChars) {
        int strPos = 0;
        int stripCharsPos = 0;
        for (; stripCharsPos < stripChars.length() && strPos < str.length(); stripCharsPos++) {

            // Jump forward within str over any white space characters that are NOT part of stripChars
            while ((stripChars.charAt(stripCharsPos) != str.charAt(strPos)) &&
                    strPos < str.length() &&
                    StringUtils.isWhitespace(str.substring(strPos, strPos + 1))) {
                strPos++;
            }

            if (strPos < str.length()) {
                if (stripChars.charAt(stripCharsPos) != str.charAt(strPos)) {
                    break;
                } else {
                    strPos++;
                }
            }
        }

        return StringUtils.substring(str, strPos);
    }
}