/**
    * Copyright 2005-2015 The Kuali Foundation
    *
    * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
    *
   * 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.kuali.rice.krad.uif.component;
  
  import org.apache.commons.lang.StringUtils;
  import org.kuali.rice.krad.datadictionary.parse.BeanTag;
  import org.kuali.rice.krad.datadictionary.parse.BeanTagAttribute;
  import org.springframework.util.MethodInvoker;
  import org.springframework.util.ReflectionUtils;
  
  import java.io.Serializable;
  import java.lang.reflect.Method;
  
  /**
   * Extends <code>MethodInvoker</code> to add properties for specifying
   * a method for invocation within the UIF
   *
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  @BeanTag(name = "methodInvokerConfig-bean", parent = "Uif-MethodInvokerConfig")
  public class MethodInvokerConfig extends MethodInvoker implements Serializable {
      private static final long serialVersionUID = 6626790175367500081L;
  
      private String staticMethod;
      private Class[] argumentTypes;
  
      /**
       * Set a fully qualified static method name to invoke,
       * e.g. "example.MyExampleClass.myExampleMethod".
       * Convenient alternative to specifying targetClass and targetMethod.
       *
       * @return static method to invoke
       */
      @BeanTagAttribute(name = "staticMethod")
      public String getStaticMethod() {
          return staticMethod;
      }
  
      /**
       * Override to catch a set staticMethod since super does
       * not contain a getter
       *
       * @param staticMethod static method to invoke
       */
      @Override
      public void setStaticMethod(String staticMethod) {
          super.setStaticMethod(staticMethod);
          this.staticMethod = staticMethod;
      }
  
      /**
       * Declared argument types for the method to be invoked, if not set the types will
       * be retrieved based on the target class and target name
       *
       * @return method argument types
       */
      @BeanTagAttribute(name = "argumentTypes", type = BeanTagAttribute.AttributeType.LISTBEAN)
      public Class[] getArgumentTypes() {
          if (argumentTypes == null) {
              return getMethodArgumentTypes();
          }
  
          return argumentTypes;
      }
  
      /**
       * Setter for the method argument types that should be invoked
       *
       * @param argumentTypes
       */
      public void setArgumentTypes(Class[] argumentTypes) {
          this.argumentTypes = argumentTypes;
      }
  
      /**
       * Finds the method on the target class that matches the target name and
       * returns the declared parameter types
       *
       * @return method parameter types
       */
      protected Class[] getMethodArgumentTypes() {
          if (StringUtils.isNotBlank(staticMethod)) {
              int lastDotIndex = this.staticMethod.lastIndexOf('.');
              if (lastDotIndex == -1 || lastDotIndex == this.staticMethod.length()) {
                  throw new IllegalArgumentException("staticMethod must be a fully qualified class plus method name: "
                          + "e.g. 'example.MyExampleClass.myExampleMethod'");
             }
             String className = this.staticMethod.substring(0, lastDotIndex);
             String methodName = this.staticMethod.substring(lastDotIndex + 1);
             try {
                 setTargetClass(resolveClassName(className));
             } catch (ClassNotFoundException e) {
                 throw new RuntimeException("Unable to get class for name: " + className);
             }
             setTargetMethod(methodName);
         }
 
         Method[] candidates = ReflectionUtils.getAllDeclaredMethods(getTargetClass());
         for (Method candidate : candidates) {
             if (candidate.getName().equals(getTargetMethod())) {
                 return candidate.getParameterTypes();
             }
         }
 
         return null;
     }
 
 }