content: /*
   * 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.camel.component.bean;
  
  import org.apache.camel.spi.ClassResolver;
  import org.apache.camel.util.ObjectHelper;
  import org.apache.camel.util.StringHelper;
  
  /**
   * Helper for the bean component.
   */
  public final class BeanHelper {
  
      private BeanHelper() {
          // utility class
      }
  
      /**
       * Determines and maps the given value is valid according to the supported values by the bean component.
       *
       * @param  value the value
       * @return       the parameter type the given value is being mapped as, or <tt>null</tt> if not valid.
       */
      public static Class<?> getValidParameterType(String value) {
          if (ObjectHelper.isEmpty(value)) {
              return null;
          }
  
          // trim value
          value = value.trim();
  
          // single quoted is valid
          if (value.startsWith("'") && value.endsWith("'")) {
              return String.class;
          }
  
          // double quoted is valid
          if (value.startsWith("\"") && value.endsWith("\"")) {
              return String.class;
          }
  
          // true or false is valid (boolean)
          if (value.equals("true") || value.equals("false")) {
              return Boolean.class;
          }
  
          // null is valid (to force a null value)
          if (value.equals("null")) {
              return Object.class;
          }
  
          // simple language tokens is valid
          if (StringHelper.hasStartToken(value, "simple")) {
              return Object.class;
          }
  
          // numeric is valid
          boolean numeric = true;
          char[] chars = value.toCharArray();
          for (int i = 0; i < chars.length; i++) {
              char ch = chars[i];
              if (i == 0 && ch == '-') {
                  continue;
              }
              if (!Character.isDigit(ch)) {
                  numeric = false;
                  break;
              }
          }
          if (numeric) {
              return Number.class;
          }
  
          // not valid
          return null;
      }
  
      /**
       * Determines if the given value is valid according to the supported values by the bean component.
       *
       * @param  value the value
       * @return       <tt>true</tt> if valid, <tt>false</tt> otherwise
       */
      public static boolean isValidParameterValue(String value) {
          if (ObjectHelper.isEmpty(value)) {
              // empty value is valid
              return true;
          }
  
          return getValidParameterType(value) != null;
      }
  
      /**
       * Determines if the given parameter type is assignable to the expected type.
       * <p/>
       * This implementation will check if the given parameter type matches the expected type as class using either
       * <ul>
       * <li>FQN class name - com.foo.MyOrder.class</li>
       * <li>Simple class name - MyOrder.class</li>
       * </ul>
       * If the given parameter type is <b>not</b> a class, then <tt>null</tt> is returned
       *
       * @param  resolver      the class resolver
       * @param  parameterType the parameter type as a String, can be a FQN or a simple name of the class (must end with
       *                       .class)
       * @param  expectedType  the expected type
       * @return               <tt>null</tt> if parameter type is <b>not</b> a class, <tt>true</tt> if parameter type is
       *                       assignable, <tt>false</tt> if not assignable
       */
      public static Boolean isAssignableToExpectedType(ClassResolver resolver, String parameterType, Class<?> expectedType) {
          if (parameterType == null || !parameterType.contains(".class")) {
              // not a class so return null
              return null;
          }
          if (parameterType.contains(" ")) {
              parameterType = StringHelper.before(parameterType, " ");
          }
          if (!parameterType.endsWith(".class")) {
              // not a class so return null
              return null;
          }
  
          parameterType = parameterType.substring(0, parameterType.length() - 6); // clip .class
  
          // if its a class, then it should be assignable
          Class<?> parameterClass = resolver.resolveClass(parameterType);
          if (parameterClass == null && parameterType.equals(expectedType.getSimpleName())) {
              // it was not the FQN class name, but the simple name instead, which matched
              return true;
          }
  
          // not a class so return null
          if (parameterClass == null) {
              return null;
          }
  
          // if there was a class, then it must be assignable to match
          return parameterClass.isAssignableFrom(expectedType);
      }
  
  }
  