/*******************************************************************************
    * Copyright (c) 2015 LegSem.
    * All rights reserved. This program and the accompanying materials
    * are made available under the terms of the GNU Lesser Public License v2.1
    * which accompanies this distribution, and is available at
    * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
    * 
    * Contributors:
    *     LegSem - initial API and implementation
   ******************************************************************************/
  package com.legstar.coxb.impl;
  
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  import java.sql.Timestamp;
  import java.util.Date;
  
  import com.legstar.coxb.CobolElement;
  import com.legstar.coxb.ICobolComplexBinding;
  import com.legstar.coxb.common.CBinding;
  import com.legstar.coxb.host.HostException;
  
  /**
   * A generic binding for alphanumeric bindings. All alphanumeric values are
   * stored in a String.
   */
  public abstract class AbstractAlphaNumericBinding extends CBinding {
  
      /** The current value for this element. */
      private String mValue = null;
  
      /**
       * Constructor for a cobol element to java binding.
       * 
       * @param bindingName the identifier for this binding
       * @param jaxbName the name of the bound java property
       * @param jaxbType the type of the bound java property
       * @param cobolAnnotations the cobol annotations for this element
       * @param parentBinding a reference to the parent binding
       */
      public AbstractAlphaNumericBinding(final String bindingName,
              final String jaxbName, final Class < ? > jaxbType,
              final CobolElement cobolAnnotations,
              final ICobolComplexBinding parentBinding) {
          super(bindingName, jaxbName, jaxbType, cobolAnnotations, parentBinding);
      }
  
      /** {@inheritDoc} */
      public String getStringValue() throws HostException {
          return mValue;
      }
  
      /** {@inheritDoc} */
      public void setStringValue(final String value) throws HostException {
          mValue = value;
      }
  
      /** {@inheritDoc} */
      public Object getObjectValue(final Class < ? > type) throws HostException {
          if (type.equals(String.class)) {
              return mValue;
          } else if (type.equals(Date.class)) {
              return new Date(Timestamp.valueOf(mValue).getTime());
          } else if (type.isEnum()) {
              /*
               * If result is request to be an enum, return instance corresponding
               * to this value
               */
              try {
                  Method fromValue = getFromValueMethod(type);
                  return fromValue.invoke(null, mValue.trim());
              } catch (SecurityException e) {
                  throw new HostException(e);
              } catch (IllegalArgumentException e) {
                  throw new HostException(e);
              } catch (IllegalAccessException e) {
                  throw new HostException(e);
              } catch (InvocationTargetException e) {
                  throw new HostException(e);
              }
  
          } else {
              throw new HostException("Attempt to get binding "
                      + getBindingName() + " as an incompatible type " + type);
          }
      }
  
      /**
       * Enum classes can be JAXB Enum wrappers with a "fromValue" method or plain
       * POJO Enums.
       * <p/>
       * Here we lookup a method that takes a String representation of the Enum
       * and returns the Enum item.
       * 
       * @param type an Enum type
       * @return the method that turns a String into an Enum item
       * @throws HostException if method cannot be found
       */
      protected Method getFromValueMethod(Class < ? > type) throws HostException {
         try {
             Method fromValueMethod = null;
             try {
                 fromValueMethod = type.getMethod("fromValue", String.class);
             } catch (NoSuchMethodException e) {
                 fromValueMethod = type.getMethod("valueOf", String.class);
             }
             return fromValueMethod;
         } catch (SecurityException e) {
             throw new HostException(e);
         } catch (NoSuchMethodException e) {
             throw new HostException(e);
         }
     }
 
     /** {@inheritDoc} */
     public void setObjectValue(final Object value) throws HostException {
         if (value == null) {
             mValue = null;
             return;
         }
         if (value instanceof String) {
             mValue = (String) value;
         } else if (value instanceof Date) {
             mValue = new Timestamp(((Date) value).getTime()).toString();
         } else if (value instanceof Enum < ? >) {
             try {
                 Method valueMethod = getValueMethod(value.getClass());
                 mValue = (String) valueMethod.invoke(value);
             } catch (SecurityException e) {
                 throw new HostException(e);
             } catch (IllegalArgumentException e) {
                 throw new HostException(e);
             } catch (IllegalAccessException e) {
                 throw new HostException(e);
             } catch (InvocationTargetException e) {
                 throw new HostException(e);
             }
         } else {
             throw new HostException("Attempt to set binding "
                     + getBindingName() + " from an incompatible value " + value);
         }
     }
 
     /**
      * Enum classes can be JAXB Enum wrappers with a "value" method or plain
      * POJO Enums.
      * <p/>
      * Here we lookup a method that returns a String representation of the Enum
      * value by first trying the JAXB type, then the POJO type.
      * 
      * @param type the Enum type
      * @return the method that returns a String representation of that enum item
      * @throws HostException if method cannot be found
      */
     protected Method getValueMethod(Class < ? > type) throws HostException {
         try {
             Method valueMethod = null;
             try {
                 valueMethod = type.getMethod("value");
             } catch (NoSuchMethodException e) {
                 valueMethod = type.getMethod("toString");
             }
             return valueMethod;
         } catch (SecurityException e) {
             throw new HostException(e);
         } catch (NoSuchMethodException e) {
             throw new HostException(e);
         }
     }
 
     /** {@inheritDoc} */
     public boolean isSet() {
         return (mValue != null);
     }
 }