package org.springframework.security.oauth.common;
   
   import org.springframework.util.StringUtils;
   import org.springframework.util.Assert;
   
   import java.util.HashMap;
   import java.util.Map;
   import java.util.ArrayList;
   import java.util.List;
  
  /**
   * Provides several <code>String</code> manipulation methods. Copied from deleted org.springframework.security.util.StringSplitUtils
   */
  public class StringSplitUtils {
  
    private static final String[] EMPTY_STRING_ARRAY = new String[0];
  
    /**
     * Splits a <code>String</code> at the first instance of the delimiter. Does not include the delimiter in
     * the response.
     *
     * @param toSplit   the string to split
     * @param delimiter to split the string up with
     * @return a two element array with index 0 being before the delimiter, and index 1 being after the delimiter
     *         (neither element includes the delimiter)
     * @throws IllegalArgumentException if an argument was invalid
     */
    public static String[] split(String toSplit, String delimiter) {
      Assert.hasLength(toSplit, "Cannot split a null or empty string");
      Assert.hasLength(delimiter, "Cannot use a null or empty delimiter to split a string");
  
      if (delimiter.length() != 1) {
        throw new IllegalArgumentException("Delimiter can only be one character in length");
      }
  
      int offset = toSplit.indexOf(delimiter);
  
      if (offset < 0) {
        return null;
      }
  
      String beforeDelimiter = toSplit.substring(0, offset);
      String afterDelimiter = toSplit.substring(offset + 1);
  
      return new String[]{beforeDelimiter, afterDelimiter};
    }
  
    /**
     * Takes an array of <code>String</code>s, and for each element removes any instances of
     * <code>removeCharacter</code>, and splits the element based on the <code>delimiter</code>. A <code>Map</code> is
     * then generated, with the left of the delimiter providing the key, and the right of the delimiter providing the
     * value. Will trim both the key and value before adding to the <code>Map</code>.
     *
     * @param array            the array to process
     * @param delimiter        to split each element using (typically the equals symbol)
     * @param removeCharacters one or more characters to remove from each element prior to attempting the split
     *                         operation (typically the quotation mark symbol) or <code>null</code> if no removal should occur
     * @return a <code>Map</code> representing the array contents, or <code>null</code> if the array to process was
     *         null or empty
     */
    public static Map<String, String> splitEachArrayElementAndCreateMap(String[] array, String delimiter, String removeCharacters) {
      if ((array == null) || (array.length == 0)) {
        return null;
      }
  
      Map<String, String> map = new HashMap<String, String>();
  
      for (int i = 0; i < array.length; i++) {
        String postRemove;
  
        if (removeCharacters == null) {
          postRemove = array[i];
        } else {
          postRemove = StringUtils.replace(array[i], removeCharacters, "");
        }
  
        String[] splitThisArrayElement = split(postRemove, delimiter);
  
        if (splitThisArrayElement == null) {
          continue;
        }
  
        map.put(splitThisArrayElement[0].trim(), splitThisArrayElement[1].trim());
      }
  
      return map;
    }
  
    /**
     * Splits a given string on the given separator character, skips the contents of quoted substrings
     * when looking for separators.
     * Introduced for use in DigestProcessingFilter (see SEC-506).
     *
     * This was copied and modified from commons-lang StringUtils
     * @param str the string to split
     * @param separatorChar the character by which to split the string
     * @return String array containing split string
     */
    public static String[] splitIgnoringQuotes(String str, char separatorChar) {
     if (str == null) {
       return null;
     }
 
     int len = str.length();
 
     if (len == 0) {
       return EMPTY_STRING_ARRAY;
     }
 
     List<String> list = new ArrayList<String>();
     int i = 0;
     int start = 0;
     boolean match = false;
 
     while (i < len) {
       if (str.charAt(i) == '"') {
         i++;
         while (i < len) {
           if (str.charAt(i) == '"') {
             i++;
             break;
           }
           i++;
         }
         match = true;
         continue;
       }
       if (str.charAt(i) == separatorChar) {
         if (match) {
           list.add(str.substring(start, i));
           match = false;
         }
         start = ++i;
         continue;
       }
       match = true;
       i++;
     }
     if (match) {
       list.add(str.substring(start, i));
     }
 
     return list.toArray(new String[list.size()]);
   }
 
 }