package ca.uhn.hl7v2.util;
   
   /**
    * Various string utility methods
    */
   public class StringUtil {
   
   	/**
   	 * Counts the number of lines in a string by counting the number of "\n" or
  	 * "\r" or "\r\n" sequences which appear in it
  	 */
  	public static int countLines(String theString) {
  		int retVal = 1;
  
  		for (int i = 0; i < theString.length(); i++) {
  			char nextChar = theString.charAt(i);
  			if (i > 0 && nextChar == '\n' && theString.charAt(i - 1) == '\r') {
  				continue;
  			}
  			if (nextChar == '\r' | nextChar == '\n') {
  				retVal++;
  			}
  		}
  
  		return retVal;
  	}
  
  	/**
  	 * Removes any line separators (\r ot \n) from the end of a string and
  	 * returns that string
  	 */
  	public static String chomp(String theLine) {
  		int i;
  		int start = theLine.length() - 1;
  		for (i = start; i >= 0; i--) {
  			char nextChar = theLine.charAt(i);
  			if (nextChar != '\r' && nextChar != '\n') {
  				break;
  			}
  		}
  
  		if (i == start) {
  			return theLine;
  		} else {
  			return theLine.substring(0, i + 1);
  		}
  	}
  
  	/**
  	 * Throws an IllegalArgumentException if the value is an empty string or
  	 * null
  	 */
  	public static void validateNotEmpty(String theValue) {
  		if (theValue == null || theValue.length() == 0) {
  			throw new IllegalArgumentException();
  		}
  	}
  
  	/**
  	 * Search within a string and replace one substring with another. Based on
  	 * the method within Commons-Lang StringUtils.
  	 */
  	public static String replace(String theString, String theMatch, String theReplacement) {
  		StringBuilder buf = new StringBuilder(theString.length());
  		int start = 0, end;
  		while ((end = theString.indexOf(theMatch, start)) != -1) {
  			buf.append(theString, start, end).append(theReplacement);
  			start = end + theMatch.length();
  		}
  		buf.append(theString.substring(start));
  		return buf.toString();
  	}
  	
  	public static String[] concatenate(String[] array1, String[] array2) {
  		if (array1 == null) return array2;
  		if (array2 == null) return array1;
          String[] result = new String[array1.length + array2.length];
          System.arraycopy(array1, 0, result, 0, array1.length);
          System.arraycopy(array2, 0, result, array1.length, array2.length);
          return result;
  	}
  
  	/**
  	 * Returns <code>true</code> if the string is null, or contains no non-whitespace characters
  	 */
  	public static boolean isBlank(String theString) {
  		if (theString == null) {
  			return true;
  		}
  		
  		for (int i = 0; i < theString.length(); i++) {
  			if (!Character.isWhitespace(theString.charAt(i))) {
  				return false;
  			}
  		}
  		
  		return true;
  	}
  
 	/**
 	 * Inverse of {@link #isBlank(String)}
 	 */
 	public static boolean isNotBlank(String theString) {
 		return !isBlank(theString);
 	}
 
 }