/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You 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
    *
    *      http://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 org.apache.log4j.helpers;
  
  import org.apache.log4j.Level;
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  import org.apache.logging.log4j.core.lookup.StrSubstitutor;
  import org.apache.logging.log4j.util.LoaderUtil;
  
  import java.io.InterruptedIOException;
  import java.lang.reflect.InvocationTargetException;
  import java.util.Properties;
  
  /**
   * A convenience class to convert property values to specific types.
   */
  public class OptionConverter {
  
      static String DELIM_START = "${";
      static char DELIM_STOP = '}';
      static int DELIM_START_LEN = 2;
      static int DELIM_STOP_LEN = 1;
      private static final Logger LOGGER = LogManager.getLogger(OptionConverter.class);
      private static final CharMap[] charMap = new CharMap[] {
          new CharMap('n', '\n'),
          new CharMap('r', '\r'),
          new CharMap('t', '\t'),
          new CharMap('f', '\f'),
          new CharMap('\b', '\b'),
          new CharMap('\"', '\"'),
          new CharMap('\'', '\''),
          new CharMap('\\', '\\')
      };
  
      /**
       * OptionConverter is a static class.
       */
      private OptionConverter() {
      }
  
      public static String[] concatanateArrays(String[] l, String[] r) {
          int len = l.length + r.length;
          String[] a = new String[len];
  
          System.arraycopy(l, 0, a, 0, l.length);
          System.arraycopy(r, 0, a, l.length, r.length);
  
          return a;
      }
  
      public static String convertSpecialChars(String s) {
          char c;
          int len = s.length();
          StringBuilder sbuf = new StringBuilder(len);
  
          int i = 0;
          while (i < len) {
              c = s.charAt(i++);
              if (c == '\\') {
                  c = s.charAt(i++);
                  for (CharMap entry : charMap) {
                      if (entry.key == c) {
                          c = entry.replacement;
                      }
                  }
              }
              sbuf.append(c);
          }
          return sbuf.toString();
      }
  
  
      /**
       * Very similar to <code>System.getProperty</code> except
       * that the {@link SecurityException} is hidden.
       *
       * @param key The key to search for.
       * @param def The default value to return.
       * @return the string value of the system property, or the default
       * value if there is no property with that key.
       * @since 1.1
       */
      public static String getSystemProperty(String key, String def) {
         try {
             return System.getProperty(key, def);
         } catch (Throwable e) { // MS-Java throws com.ms.security.SecurityExceptionEx
             LOGGER.debug("Was not allowed to read system property \"{}\".", key);
             return def;
         }
     }
 
     /**
      * If <code>value</code> is "true", then <code>true</code> is
      * returned. If <code>value</code> is "false", then
      * <code>true</code> is returned. Otherwise, <code>default</code> is
      * returned.
      *
      * <p>Case of value is unimportant.
      * @param value The value to convert.
      * @param dEfault The default value.
      * @return the value of the result.
      */
     public static boolean toBoolean(String value, boolean dEfault) {
         if (value == null) {
             return dEfault;
         }
         String trimmedVal = value.trim();
         if ("true".equalsIgnoreCase(trimmedVal)) {
             return true;
         }
         if ("false".equalsIgnoreCase(trimmedVal)) {
             return false;
         }
         return dEfault;
     }
 
     /**
      * Converts a standard or custom priority level to a Level
      * object.  <p> If <code>value</code> is of form
      * "level#classname", then the specified class' toLevel method
      * is called to process the specified level string; if no '#'
      * character is present, then the default {@link org.apache.log4j.Level}
      * class is used to process the level value.
      *
      * <p>As a special case, if the <code>value</code> parameter is
      * equal to the string "NULL", then the value <code>null</code> will
      * be returned.
      *
      * <p> If any error occurs while converting the value to a level,
      * the <code>defaultValue</code> parameter, which may be
      * <code>null</code>, is returned.
      *
      * <p> Case of <code>value</code> is insignificant for the level level, but is
      * significant for the class name part, if present.
      * @param value The value to convert.
      * @param defaultValue The default value.
      * @return the value of the result.
      *
      * @since 1.1
      */
     public static Level toLevel(String value, Level defaultValue) {
         if (value == null) {
             return defaultValue;
         }
 
         value = value.trim();
 
         int hashIndex = value.indexOf('#');
         if (hashIndex == -1) {
             if ("NULL".equalsIgnoreCase(value)) {
                 return null;
             }
             // no class name specified : use standard Level class
             return Level.toLevel(value, defaultValue);
         }
 
         Level result = defaultValue;
 
         String clazz = value.substring(hashIndex + 1);
         String levelName = value.substring(0, hashIndex);
 
         // This is degenerate case but you never know.
         if ("NULL".equalsIgnoreCase(levelName)) {
             return null;
         }
 
         LOGGER.debug("toLevel" + ":class=[" + clazz + "]"
                 + ":pri=[" + levelName + "]");
 
         try {
             Class<?> customLevel = LoaderUtil.loadClass(clazz);
 
             // get a ref to the specified class' static method
             // toLevel(String, org.apache.log4j.Level)
             Class<?>[] paramTypes = new Class[] { String.class, org.apache.log4j.Level.class };
             java.lang.reflect.Method toLevelMethod =
                     customLevel.getMethod("toLevel", paramTypes);
 
             // now call the toLevel method, passing level string + default
             Object[] params = new Object[]{levelName, defaultValue};
             Object o = toLevelMethod.invoke(null, params);
 
             result = (Level) o;
         } catch (ClassNotFoundException e) {
             LOGGER.warn("custom level class [" + clazz + "] not found.");
         } catch (NoSuchMethodException e) {
             LOGGER.warn("custom level class [" + clazz + "]"
                     + " does not have a class function toLevel(String, Level)", e);
         } catch (java.lang.reflect.InvocationTargetException e) {
             if (e.getTargetException() instanceof InterruptedException
                     || e.getTargetException() instanceof InterruptedIOException) {
                 Thread.currentThread().interrupt();
             }
             LOGGER.warn("custom level class [" + clazz + "]"
                     + " could not be instantiated", e);
         } catch (ClassCastException e) {
             LOGGER.warn("class [" + clazz
                     + "] is not a subclass of org.apache.log4j.Level", e);
         } catch (IllegalAccessException e) {
             LOGGER.warn("class [" + clazz +
                     "] cannot be instantiated due to access restrictions", e);
         } catch (RuntimeException e) {
             LOGGER.warn("class [" + clazz + "], level [" + levelName +
                     "] conversion failed.", e);
         }
         return result;
     }
 
     /**
      * Instantiate an object given a class name. Check that the
      * <code>className</code> is a subclass of
      * <code>superClass</code>. If that test fails or the object could
      * not be instantiated, then <code>defaultValue</code> is returned.
      *
      * @param className    The fully qualified class name of the object to instantiate.
      * @param superClass   The class to which the new object should belong.
      * @param defaultValue The object to return in case of non-fulfillment
      * @return The created object.
      */
     public static Object instantiateByClassName(String className, Class<?> superClass,
             Object defaultValue) {
         if (className != null) {
             try {
                 Object obj = LoaderUtil.newInstanceOf(className);
                 if (!superClass.isAssignableFrom(obj.getClass())) {
                     LOGGER.error("A \"{}\" object is not assignable to a \"{}\" variable", className,
                             superClass.getName());
                     return defaultValue;
                 }
                 return obj;
             } catch (ClassNotFoundException | NoSuchMethodException | IllegalAccessException
                     | InstantiationException | InvocationTargetException e) {
                 LOGGER.error("Could not instantiate class [" + className + "].", e);
             }
         }
         return defaultValue;
     }
 
 
     /**
      * Perform variable substitution in string <code>val</code> from the
      * values of keys found in the system propeties.
      *
      * <p>The variable substitution delimeters are <b>${</b> and <b>}</b>.
      *
      * <p>For example, if the System properties contains "key=value", then
      * the call
      * <pre>
      * String s = OptionConverter.substituteVars("Value of key is ${key}.");
      * </pre>
      * <p>
      * will set the variable <code>s</code> to "Value of key is value.".
      *
      * <p>If no value could be found for the specified key, then the
      * <code>props</code> parameter is searched, if the value could not
      * be found there, then substitution defaults to the empty string.
      *
      * <p>For example, if system propeties contains no value for the key
      * "inexistentKey", then the call
      *
      * <pre>
      * String s = OptionConverter.subsVars("Value of inexistentKey is [${inexistentKey}]");
      * </pre>
      * will set <code>s</code> to "Value of inexistentKey is []"
      *
      * <p>An {@link IllegalArgumentException} is thrown if
      * <code>val</code> contains a start delimeter "${" which is not
      * balanced by a stop delimeter "}". </p>
      *
      * <p><b>Author</b> Avy Sharell</p>
      *
      * @param val The string on which variable substitution is performed.
      * @param props The properties to use for the substitution.
      * @return The substituted string.
      * @throws IllegalArgumentException if <code>val</code> is malformed.
      */
     public static String substVars(String val, Properties props) throws IllegalArgumentException {
         return StrSubstitutor.replace(val, props);
     }
 
     public static org.apache.logging.log4j.Level convertLevel(String level,
             org.apache.logging.log4j.Level defaultLevel) {
         Level l = toLevel(level, null);
         return l != null ? convertLevel(l) : defaultLevel;
     }
 
     public static  org.apache.logging.log4j.Level convertLevel(Level level) {
         if (level == null) {
             return org.apache.logging.log4j.Level.ERROR;
         }
         if (level.isGreaterOrEqual(Level.FATAL)) {
             return org.apache.logging.log4j.Level.FATAL;
         } else if (level.isGreaterOrEqual(Level.ERROR)) {
             return org.apache.logging.log4j.Level.ERROR;
         } else if (level.isGreaterOrEqual(Level.WARN)) {
             return org.apache.logging.log4j.Level.WARN;
         } else if (level.isGreaterOrEqual(Level.INFO)) {
             return org.apache.logging.log4j.Level.INFO;
         } else if (level.isGreaterOrEqual(Level.DEBUG)) {
             return org.apache.logging.log4j.Level.DEBUG;
         } else if (level.isGreaterOrEqual(Level.TRACE)) {
             return org.apache.logging.log4j.Level.TRACE;
         }
         return org.apache.logging.log4j.Level.ALL;
     }
 
     public static Level convertLevel(org.apache.logging.log4j.Level level) {
         if (level == null) {
             return Level.ERROR;
         }
         switch (level.getStandardLevel()) {
             case FATAL:
                 return Level.FATAL;
             case WARN:
                 return Level.WARN;
             case INFO:
                 return Level.INFO;
             case DEBUG:
                 return Level.DEBUG;
             case TRACE:
                 return Level.TRACE;
             case ALL:
                 return Level.ALL;
             case OFF:
                 return Level.OFF;
             default:
                 return Level.ERROR;
         }
     }
 
     /**
      * Find the value corresponding to <code>key</code> in
      * <code>props</code>. Then perform variable substitution on the
      * found value.
      * @param key The key used to locate the substitution string.
      * @param props The properties to use in the substitution.
      * @return The substituted string.
      */
     public static String findAndSubst(String key, Properties props) {
         String value = props.getProperty(key);
         if (value == null) {
             return null;
         }
 
         try {
             return substVars(value, props);
         } catch (IllegalArgumentException e) {
             LOGGER.error("Bad option value [{}].", value, e);
             return value;
         }
     }
 
     private static class CharMap {
         final char key;
         final char replacement;
 
         public CharMap(char key, char replacement) {
             this.key = key;
             this.replacement = replacement;
         }
     }
 }