content: /*
   *  Copyright (C) 2010 Ryszard Wiśniewski <brut.alll@gmail.com>
   *  Copyright (C) 2010 Connor Tumbleson <connor.tumbleson@gmail.com>
   *
   *  Licensed under the Apache License, Version 2.0 (the "License");
   *  you may not use this file except in compliance with the License.
   *  You may obtain a copy of the License at
   *
   *       https://www.apache.org/licenses/LICENSE-2.0
   *
   *  Unless required by applicable law or agreed to in writing, software
   *  distributed under the License is distributed on an "AS IS" BASIS,
   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *  See the License for the specific language governing permissions and
   *  limitations under the License.
   */
  package brut.androlib.meta;
  
  import org.apache.commons.text.StringEscapeUtils;
  import org.apache.commons.text.translate.CharSequenceTranslator;
  
  import java.io.IOException;
  import java.io.StringWriter;
  import java.io.Writer;
  
  public class YamlStringEscapeUtils {
  
      public static String escapeString(String str) {
          return escapeJavaStyleString(str, false, false);
      }
  
      /**
       * @param str String to escape values in, may be null
       * @param escapeSingleQuotes escapes single quotes if <code>true</code>
       * @param escapeForwardSlash TODO
       * @return the escaped string
       */
      private static String escapeJavaStyleString(String str, boolean escapeSingleQuotes, boolean escapeForwardSlash) {
          if (str == null) {
              return null;
          }
          try {
              StringWriter writer = new StringWriter(str.length() * 2);
              escapeJavaStyleString(writer, str, escapeSingleQuotes, escapeForwardSlash);
              return writer.toString();
          } catch (IOException ioe) {
              // this should never ever happen while writing to a StringWriter
              throw new RuntimeException(ioe);
          }
      }
  
      /**
       * @param out write to receieve the escaped string
       * @param str String to escape values in, may be null
       * @param escapeSingleQuote escapes single quotes if <code>true</code>
       * @param escapeForwardSlash TODO
       * @throws IOException if an IOException occurs
       */
      private static void escapeJavaStyleString(Writer out, String str, boolean escapeSingleQuote,
                                                boolean escapeForwardSlash) throws IOException {
          if (out == null) {
              throw new IllegalArgumentException("The Writer must not be null");
          }
          if (str == null) {
              return;
          }
          int sz;
          sz = str.length();
          for (int i = 0; i < sz; i++) {
              char ch = str.charAt(i);
              // "[^\t\n\r\u0020-\u007E\u0085\u00A0-\uD7FF\uE000-\uFFFD]"
              // handle unicode
              if (ch > 0xFFFD) {
                  out.write("\\u" + CharSequenceTranslator.hex(ch));
              } else if (ch > 0xD7FF && ch < 0xE000) {
                  out.write("\\u" + CharSequenceTranslator.hex(ch));
              } else if (ch > 0x7E && ch != 0x85 && ch < 0xA0) {
                  out.write("\\u00" + CharSequenceTranslator.hex(ch));
              } else if (ch < 32) {
                  switch (ch) {
                      case '\t' :
                          out.write('\\');
                          out.write('t');
                          break;
                      case '\n' :
                          out.write('\\');
                          out.write('n');
                          break;
                      case '\r' :
                          out.write('\\');
                          out.write('r');
                          break;
                      default :
                          if (ch > 0xf) {
                              out.write("\\u00" + CharSequenceTranslator.hex(ch));
                          } else {
                              out.write("\\u000" + CharSequenceTranslator.hex(ch));
                          }
                          break;
                  }
              } else {
                  switch (ch) {
                      case '\'' :
                          if (escapeSingleQuote) {
                              out.write('\\');
                          }
                          out.write('\'');
                          break;
                      case '"' :
                          out.write('\\');
                          out.write('"');
                          break;
                      case '\\' :
                          out.write('\\');
                          out.write('\\');
                          break;
                      case '/' :
                          if (escapeForwardSlash) {
                              out.write('\\');
                          }
                          out.write('/');
                          break;
                      default :
                          out.write(ch);
                          break;
                  }
              }
          }
      }
  
      /**
       * <p>Unescapes any Java literals found in the <code>String</code>.
       * For example, it will turn a sequence of <code>'\'</code> and
       * <code>'n'</code> into a newline character, unless the <code>'\'</code>
       * is preceded by another <code>'\'</code>.</p>
       *
       * @param str  the <code>String</code> to unescape, may be null
       * @return a new unescaped <code>String</code>, <code>null</code> if null string input
       */
      public static String unescapeString(String str) {
          return StringEscapeUtils.unescapeJava(str);
      }
  }
  