/*******************************************************************************
    * 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.reflect;
  
  import java.lang.reflect.Constructor;
  import java.lang.reflect.Field;
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  
  import javax.xml.bind.annotation.XmlElement;
  
  import com.legstar.coxb.CobolElement;
  import com.legstar.coxb.CobolJavaTypeAdapter;
  import com.legstar.coxb.ICobolBinding;
  import com.legstar.coxb.ICobolChoiceBinding;
  import com.legstar.coxb.ICobolComplexBinding;
  import com.legstar.coxb.impl.CArrayBinaryBinding;
  import com.legstar.coxb.impl.CArrayDbcsBinding;
  import com.legstar.coxb.impl.CArrayDoubleBinding;
  import com.legstar.coxb.impl.CArrayFloatBinding;
  import com.legstar.coxb.impl.CArrayNationalBinding;
  import com.legstar.coxb.impl.CArrayOctetStreamBinding;
  import com.legstar.coxb.impl.CArrayPackedDecimalBinding;
  import com.legstar.coxb.impl.CArrayStringBinding;
  import com.legstar.coxb.impl.CArrayZonedDecimalBinding;
  import com.legstar.coxb.impl.CBinaryBinding;
  import com.legstar.coxb.impl.CDbcsBinding;
  import com.legstar.coxb.impl.CDoubleBinding;
  import com.legstar.coxb.impl.CFloatBinding;
  import com.legstar.coxb.impl.CNationalBinding;
  import com.legstar.coxb.impl.COctetStreamBinding;
  import com.legstar.coxb.impl.CPackedDecimalBinding;
  import com.legstar.coxb.impl.CStringBinding;
  import com.legstar.coxb.impl.CZonedDecimalBinding;
  import com.legstar.coxb.impl.RedefinesMap;
  import com.legstar.coxb.util.ClassUtil;
  import com.legstar.coxb.util.NameUtil;
  
  /**
   * Creates specialized COBOL/Java bindings based upon properties discovered
   * using reflection on JAXB classes.
   * 
   */
  public final class ReflectBindingFactory {
  
      /**
       * Choice bindings derive their name from the redefined alternative.
       */
      private static final String CHOICE_NAME_SUFFIX = "Choice";
  
      /**
       * Complex array bindings derive their name from the occuring complex item.
       */
      private static final String COMPLEX_ARRAY_NAME_SUFFIX = "Wrapper";
  
      /**
       * Utility class.
       */
      private ReflectBindingFactory() {
  
      }
  
      /**
       * Create a specialized binding by analyzing a JAXB class field.
       * <p/>
       * The strategy is as follows:
       * <ul>
       * <li>If there is an explicit adapter, then it becomes the binding</li>
       * <li>Otherwise binding is inferred from COBOL annotations</li>
       * </ul>
       * 
       * @param jaxbType the java property type
       * @param field the JAXB class field
       * @param parentBinding the parent binding (null if none)
       * @param jaxbObjectFactory the JAXB object factory
       * @return a specialized binding
       */
      public static ICobolBinding createBinding(final Class < ? > jaxbType,
              final Field field, final ICobolComplexBinding parentBinding,
              final Object jaxbObjectFactory) throws ReflectBindingException {
  
          CobolElement cobolAnnotations = field.getAnnotation(CobolElement.class);
          if (cobolAnnotations == null) {
              throw new ReflectBindingException(
                      "No cobol annotations found for field " + field.getName());
          }
          String jaxbName = getJaxbName(parentBinding.getJaxbType(), field,
                  cobolAnnotations.maxOccurs());
  
          CobolJavaTypeAdapter adapter = field
                  .getAnnotation(CobolJavaTypeAdapter.class);
         if (adapter != null) {
             return getCustomAdapter(adapter, jaxbName, jaxbType,
                     cobolAnnotations, parentBinding);
         }
 
         return createBinding(jaxbName, jaxbType, cobolAnnotations,
                 parentBinding, jaxbObjectFactory);
 
     }
 
     /**
      * Dispatch creation methods based on the COBOL type.
      * 
      * @param jaxbName the java property name
      * @param jaxbType the java property type
      * @param cobolAnnotations the COBOL annotations
      * @param parentBinding the parent binding (null if none)
      * @param jaxbObjectFactory the JAXB object factory
      * @return a specialized binding
      * @throws ReflectBindingException
      */
     public static ICobolBinding createBinding(final String jaxbName,
             final Class < ? > jaxbType, final CobolElement cobolAnnotations,
             final ICobolComplexBinding parentBinding,
             final Object jaxbObjectFactory) throws ReflectBindingException {
 
         switch (cobolAnnotations.type()) {
         case GROUP_ITEM:
             return createComplexBinding(jaxbName, jaxbType, cobolAnnotations,
                     parentBinding, jaxbObjectFactory);
         case ALPHABETIC_ITEM:
         case ALPHANUMERIC_EDITED_ITEM:
         case ALPHANUMERIC_ITEM:
         case NUMERIC_EDITED_ITEM:
         case EXTERNAL_FLOATING_ITEM:
             return createStringBinding(jaxbName, jaxbType, cobolAnnotations,
                     parentBinding);
         case NATIONAL_ITEM:
             return createNationalBinding(jaxbName, jaxbType, cobolAnnotations,
                     parentBinding);
         case PACKED_DECIMAL_ITEM:
             return createPackedDecimalBinding(jaxbName, jaxbType,
                     cobolAnnotations, parentBinding);
         case ZONED_DECIMAL_ITEM:
             return createZonedDecimalBinding(jaxbName, jaxbType,
                     cobolAnnotations, parentBinding);
         case DBCS_ITEM:
             return createDbcsBinding(jaxbName, jaxbType, cobolAnnotations,
                     parentBinding);
         case OCTET_STREAM_ITEM:
         case INDEX_ITEM:
         case POINTER_ITEM:
         case PROC_POINTER_ITEM:
         case FUNC_POINTER_ITEM:
             return createOctetStreamBinding(jaxbName, jaxbType,
                     cobolAnnotations, parentBinding);
         case BINARY_ITEM:
         case NATIVE_BINARY_ITEM:
             return createBinaryBinding(jaxbName, jaxbType, cobolAnnotations,
                     parentBinding);
         case SINGLE_FLOAT_ITEM:
             return createFloatBinding(jaxbName, jaxbType, cobolAnnotations,
                     parentBinding);
         case DOUBLE_FLOAT_ITEM:
             return createDoubleBinding(jaxbName, jaxbType, cobolAnnotations,
                     parentBinding);
         default:
             throw (new ReflectBindingException(
                     "Unrecognized cobol type for field "
                             + cobolAnnotations.cobolName()));
         }
 
     }
 
     /**
      * Create a group element type.
      * 
      * @param jaxbName the java property name
      * @param jaxbType the java property type
      * @param cobolAnnotations the cobol annotations for this element
      * @param parentBinding the parent binding (null if none)
      * @param jaxbObjectFactory the JAXB object factory
      * @return the new cobol element description
      * @throws ReflectBindingException if cobol description cannot be created
      */
     public static ICobolBinding createComplexBinding(final String jaxbName,
             final Class < ? > jaxbType, final CobolElement cobolAnnotations,
             final ICobolComplexBinding parentBinding,
             final Object jaxbObjectFactory) throws ReflectBindingException {
 
         /* JAXB considers a member to be an array only if maxOccurs > 1 */
         if (cobolAnnotations.maxOccurs() > 1) {
             /* A single complex binding is used for all items */
             ICobolComplexBinding item = new CComplexReflectBinding(jaxbName,
                     jaxbName, jaxbType, cobolAnnotations, parentBinding,
                     jaxbObjectFactory);
             return new CArrayComplexReflectBinding(jaxbName
                     + COMPLEX_ARRAY_NAME_SUFFIX, jaxbName, jaxbType,
                     cobolAnnotations, parentBinding, item, jaxbObjectFactory);
         } else {
             return new CComplexReflectBinding(jaxbName, jaxbName, jaxbType,
                     cobolAnnotations, parentBinding, jaxbObjectFactory);
         }
     }
 
     /**
      * Create a choice element type which will group all alternatives.
      * <p/>
      * The identifier of this choice element is built from the first alternative
      * java name.
      * <p/>
      * The choice element replaces the redefined element in the parent
      * hierarchy. All alternative (redefining elements) are then added to the
      * choice.
      * 
      * @param cobolAnnotations the cobol annotations for this element
      * @param parentBinding the parent binding (null if none)
      * @param cobolBinding the cobol descriptor for this element
      * @param redefinesMap the current list of redefined items
      * @return the new cobol element description
      * @throws ReflectBindingException if cobol binding cannot be created
      */
     public static ICobolChoiceBinding createChoiceBinding(
             final ICobolComplexBinding parentBinding,
             final ICobolBinding cobolBinding, final RedefinesMap redefinesMap)
             throws ReflectBindingException {
 
         String choiceJaxbName = cobolBinding.getJaxbName() + CHOICE_NAME_SUFFIX;
 
         CChoiceReflectBinding choice = new CChoiceReflectBinding(
                 choiceJaxbName, parentBinding);
 
         /*
          * Propagate unmarshaling/marshaling strategies from first alternative
          * to the new choice element.
          */
         choice.setMarshalChoiceStrategyClassName(cobolBinding
                 .getMarshalChoiceStrategyClassName());
         choice.setUnmarshalChoiceStrategyClassName(cobolBinding
                 .getUnmarshalChoiceStrategyClassName());
         choice.setCobolName(cobolBinding.getCobolName());
 
         /*
          * Add the redefined item as the first alternative in the choice element
          */
         choice.addAlternative(cobolBinding);
 
         /* Add this choice element in the redefines map */
         redefinesMap.updateChoiceElement(cobolBinding.getCobolName(), choice);
 
         /* Return the choice as the current element for caller */
         return choice;
 
     }
 
     /**
      * Create a String binding type.
      * 
      * @param jaxbName the java property name
      * @param jaxbType the java property type
      * @param cobolAnnotations the cobol annotations for this element
      * @param parentBinding the parent binding
      * @return the new cobol element description
      * @throws ReflectBindingException if cobol description cannot be created
      */
     public static ICobolBinding createStringBinding(final String jaxbName,
             final Class < ? > jaxbType, final CobolElement cobolAnnotations,
             final ICobolComplexBinding parentBinding)
             throws ReflectBindingException {
 
         if (cobolAnnotations.maxOccurs() > 0) {
             return new CArrayStringBinding(jaxbName, jaxbName, jaxbType,
                     cobolAnnotations, parentBinding);
         } else {
             return new CStringBinding(jaxbName, jaxbName, jaxbType,
                     cobolAnnotations, parentBinding);
         }
     }
 
     /**
      * Create a OctetStream binding type.
      * 
      * @param jaxbName the java property name
      * @param jaxbType the java property type
      * @param cobolAnnotations the cobol annotations for this element
      * @param parentBinding the parent binding
      * @return the new cobol element description
      * @throws ReflectBindingException if cobol description cannot be created
      */
     public static ICobolBinding createOctetStreamBinding(final String jaxbName,
             final Class < ? > jaxbType, final CobolElement cobolAnnotations,
             final ICobolComplexBinding parentBinding)
             throws ReflectBindingException {
 
         if (cobolAnnotations.maxOccurs() > 0) {
             return new CArrayOctetStreamBinding(jaxbName, jaxbName, jaxbType,
                     cobolAnnotations, parentBinding);
         } else {
             return new COctetStreamBinding(jaxbName, jaxbName, jaxbType,
                     cobolAnnotations, parentBinding);
         }
     }
 
     /**
      * Create a National binding type.
      * 
      * @param jaxbName the java property name
      * @param jaxbType the java property type
      * @param cobolAnnotations the cobol annotations for this element
      * @param parentBinding the parent binding
      * @return the new cobol element description
      * @throws ReflectBindingException if cobol description cannot be created
      */
     public static ICobolBinding createNationalBinding(final String jaxbName,
             final Class < ? > jaxbType, final CobolElement cobolAnnotations,
             final ICobolComplexBinding parentBinding)
             throws ReflectBindingException {
 
         if (cobolAnnotations.maxOccurs() > 0) {
             return new CArrayNationalBinding(jaxbName, jaxbName, jaxbType,
                     cobolAnnotations, parentBinding);
         } else {
             return new CNationalBinding(jaxbName, jaxbName, jaxbType,
                     cobolAnnotations, parentBinding);
         }
     }
 
     /**
      * Create a Dbcs binding type.
      * 
      * @param jaxbName the java property name
      * @param jaxbType the java property type
      * @param cobolAnnotations the cobol annotations for this element
      * @param parentBinding the parent binding
      * @return the new cobol element description
      * @throws ReflectBindingException if cobol description cannot be created
      */
     public static ICobolBinding createDbcsBinding(final String jaxbName,
             final Class < ? > jaxbType, final CobolElement cobolAnnotations,
             final ICobolComplexBinding parentBinding)
             throws ReflectBindingException {
 
         if (cobolAnnotations.maxOccurs() > 0) {
             return new CArrayDbcsBinding(jaxbName, jaxbName, jaxbType,
                     cobolAnnotations, parentBinding);
         } else {
             return new CDbcsBinding(jaxbName, jaxbName, jaxbType,
                     cobolAnnotations, parentBinding);
         }
     }
 
     /**
      * Create a PackedDecimal binding type.
      * 
      * @param jaxbName the java property name
      * @param jaxbType the java property type
      * @param cobolAnnotations the cobol annotations for this element
      * @param parentBinding the parent binding
      * @return the new cobol element description
      * @throws ReflectBindingException if cobol description cannot be created
      */
     public static ICobolBinding createPackedDecimalBinding(
             final String jaxbName, final Class < ? > jaxbType,
             final CobolElement cobolAnnotations,
             final ICobolComplexBinding parentBinding)
             throws ReflectBindingException {
 
         if (cobolAnnotations.maxOccurs() > 0) {
             return new CArrayPackedDecimalBinding(jaxbName, jaxbName, jaxbType,
                     cobolAnnotations, parentBinding);
         } else {
             return new CPackedDecimalBinding(jaxbName, jaxbName, jaxbType,
                     cobolAnnotations, parentBinding);
         }
     }
 
     /**
      * Create a ZonedDecimal binding type.
      * 
      * @param jaxbName the java property name
      * @param jaxbType the java property type
      * @param cobolAnnotations the cobol annotations for this element
      * @param parentBinding the parent binding
      * @return the new cobol element description
      * @throws ReflectBindingException if cobol description cannot be created
      */
     public static ICobolBinding createZonedDecimalBinding(
             final String jaxbName, final Class < ? > jaxbType,
             final CobolElement cobolAnnotations,
             final ICobolComplexBinding parentBinding)
             throws ReflectBindingException {
 
         if (cobolAnnotations.maxOccurs() > 0) {
             return new CArrayZonedDecimalBinding(jaxbName, jaxbName, jaxbType,
                     cobolAnnotations, parentBinding);
         } else {
             return new CZonedDecimalBinding(jaxbName, jaxbName, jaxbType,
                     cobolAnnotations, parentBinding);
         }
     }
 
     /**
      * Create a Binary binding type.
      * 
      * @param jaxbName the java property name
      * @param jaxbType the java property type
      * @param cobolAnnotations the cobol annotations for this element
      * @param parentBinding the parent binding
      * @return the new cobol element description
      * @throws ReflectBindingException if cobol description cannot be created
      */
     public static ICobolBinding createBinaryBinding(final String jaxbName,
             final Class < ? > jaxbType, final CobolElement cobolAnnotations,
             final ICobolComplexBinding parentBinding)
             throws ReflectBindingException {
 
         if (cobolAnnotations.maxOccurs() > 0) {
             return new CArrayBinaryBinding(jaxbName, jaxbName, jaxbType,
                     cobolAnnotations, parentBinding);
         } else {
             return new CBinaryBinding(jaxbName, jaxbName, jaxbType,
                     cobolAnnotations, parentBinding);
         }
     }
 
     /**
      * Create a Float binding type.
      * 
      * @param jaxbName the java property name
      * @param jaxbType the java property type
      * @param cobolAnnotations the cobol annotations for this element
      * @param parentBinding the parent binding
      * @return the new cobol element description
      * @throws ReflectBindingException if cobol description cannot be created
      */
     public static ICobolBinding createFloatBinding(final String jaxbName,
             final Class < ? > jaxbType, final CobolElement cobolAnnotations,
             final ICobolComplexBinding parentBinding)
             throws ReflectBindingException {
 
         if (cobolAnnotations.maxOccurs() > 0) {
             return new CArrayFloatBinding(jaxbName, jaxbName, jaxbType,
                     cobolAnnotations, parentBinding);
         } else {
             return new CFloatBinding(jaxbName, jaxbName, jaxbType,
                     cobolAnnotations, parentBinding);
         }
     }
 
     /**
      * Create a Double binding type.
      * 
      * @param jaxbName the java property name
      * @param jaxbType the java property type
      * @param cobolAnnotations the cobol annotations for this element
      * @param parentBinding the parent binding
      * @return the new cobol element description
      * @throws ReflectBindingException if cobol description cannot be created
      */
     public static ICobolBinding createDoubleBinding(final String jaxbName,
             final Class < ? > jaxbType, final CobolElement cobolAnnotations,
             final ICobolComplexBinding parentBinding)
             throws ReflectBindingException {
 
         if (cobolAnnotations.maxOccurs() > 0) {
             return new CArrayDoubleBinding(jaxbName, jaxbName, jaxbType,
                     cobolAnnotations, parentBinding);
         } else {
             return new CDoubleBinding(jaxbName, jaxbName, jaxbType,
                     cobolAnnotations, parentBinding);
         }
     }
 
     /**
      * Get the JAXB property name usable by appending "get".
      * <p/>
      * We first try the host field name processed with the JAXB name converter
      * which strips off underscores, etc... This is the most likely situation.
      * <p/>
      * If first try does not work, we try the host field name directly. This
      * case corresponds to ECI compatibility mode which bypasses the JAXB name
      * converter.
      * <p/>
      * If this still does not work, we try the XmlElement annotation. This
      * corresponds to cases (@see numzoned) where XmlEelement annotation is used
      * to override the proposed JAXB name.
      * 
      * @param parentJaxbType the parent JAXB object type
      * @param hostField the JAXB field
      * @param maxOccurs the number of occurrences (needed to identify lists)
      * @return a property name usable to create a getter a method on the JAXB
      *         object
      * @throws ReflectBindingException
      */
     public static String getJaxbName(Class < ? > parentJaxbType,
             final Field hostField, final int maxOccurs)
             throws ReflectBindingException {
 
         Method getter = null;
         String getterPrefix = ClassUtil.getGetterPrefix(hostField.getType(),
                 maxOccurs);
 
         try {
             getter = parentJaxbType.getMethod(ClassUtil.getGetterName(
                     getterPrefix, NameUtil.toClassName(hostField.getName())));
         } catch (SecurityException e) {
             throw new ReflectBindingException(e);
         } catch (NoSuchMethodException e) {
             try {
                 getter = parentJaxbType.getMethod(ClassUtil.getGetterName(
                         getterPrefix, hostField.getName()));
             } catch (SecurityException e1) {
                 throw new ReflectBindingException(e1);
             } catch (NoSuchMethodException e1) {
                 XmlElement xmlAnnotation = hostField
                         .getAnnotation(XmlElement.class);
                 if (xmlAnnotation != null && xmlAnnotation.name() != null
                         && !xmlAnnotation.name().equals("##default")) {
                     try {
                         getter = parentJaxbType.getMethod(ClassUtil
                                 .getGetterName(getterPrefix, NameUtil
                                         .toClassName(xmlAnnotation.name())));
                     } catch (SecurityException e2) {
                         throw new ReflectBindingException(e);
                     } catch (NoSuchMethodException e2) {
                         throw new ReflectBindingException(e);
                     }
                 } else {
                     throw new ReflectBindingException(
                             "Unable to find JAXB getter method for "
                                     + hostField.getName());
                 }
             }
         }
         return getter.getName().substring(getterPrefix.length());
 
     }
 
     /**
      * Elements might be associated with a custom adapter.
      * <p/>
      * Custom adapters will usually inherit from
      * {@link com.legstar.coxb.common.CBinding} or one of its subclasses.
      * <p/>
      * The adapter must implement a constructor that takes the same parameters
      * as CBinding.
      * 
      * @param adapter the adapter annotations
      * @param jaxbName the JAXB name of the bound property
      * @param jaxbType the JAXB type of the bound property
      * @param cobolAnnotations the COBOL annotations
      * @param parentBinding the parent binding
      * @return an instance of the adapter
      * @throws ReflectBindingException if instantiation fails
      */
     protected static ICobolBinding getCustomAdapter(
             CobolJavaTypeAdapter adapter, final String jaxbName,
             final Class < ? > jaxbType, final CobolElement cobolAnnotations,
             final ICobolComplexBinding parentBinding)
             throws ReflectBindingException {
         try {
             Class < ? extends ICobolBinding > adapterClass = adapter.value();
             Constructor < ? extends ICobolBinding > ctor = adapterClass
                     .getConstructor(String.class, String.class, Class.class,
                             CobolElement.class, ICobolComplexBinding.class);
             return ctor.newInstance(jaxbName, jaxbName, jaxbType,
                     cobolAnnotations, parentBinding);
         } catch (SecurityException e) {
             throw new ReflectBindingException(e);
         } catch (NoSuchMethodException e) {
             throw new ReflectBindingException(e);
         } catch (IllegalArgumentException e) {
             throw new ReflectBindingException(e);
         } catch (InstantiationException e) {
             throw new ReflectBindingException(e);
         } catch (IllegalAccessException e) {
             throw new ReflectBindingException(e);
         } catch (InvocationTargetException e) {
             throw new ReflectBindingException(e);
         }
 
     }
 
 }