package net.sf.sapjcosupport;

 import org.apache.commons.beanutils.ConvertUtils;

 import org.apache.log4j.Logger;

 import java.lang.reflect.Field;

 import java.text.DateFormat;

 import java.text.ParseException;

 import java.text.SimpleDateFormat;

 import java.util.*;

 /**

  * This class implements the SAP <b>Search Help</b> functionality.

  * <p/>

  * As any subclass of <code>SapJcoInterface</code>, a value object is associated with this

  * implementation: {@link SapSearchHelpVO}. This is a temporary value object, that can be mapped

  * to the value object of your choice automagically.

  * <br/>

  * To do so, call the 'persistentObject' method with the class of the desired value object.

  *

  * @author Jo Vandermeeren

  * @since Mar 21, 2006 - 11:08:01 AM

  */

 public abstract class SapSearchHelp extends SapJcoInterface {

     protected final Logger log = Logger.getLogger(getClass());

     protected static final DateFormat SAP_DATE_FORMATTER = new SimpleDateFormat("yyyyMMdd");

     /**

      * Performs the actual search. Call this method after you have set all necessary properties.

      * <br/>

      * If the persistent object class was not set, instances of <code>SearchHelpVO</code> are returned.

      * <p/>

      * Each field in the 'javaFieldSelection' list should correspond with a field at the same position in the 'sapFieldSelection' list.

      *

      * @param searchHelpName     name of the SAP search help

      * @param selectionMethod    name of the selection method for the search help

      * @param maximumResults     maximum results to return

      * @param criteria           list of {@link SearchCriterion} objects

      * @param persistentObject   value object class

      * @param javaFieldSelection list of the names of the Java value object fields

      * @param sapFieldSelection  list of the names of the SAP function fields

      * @return List containing the search results as instances of the same type as specified by 'persistentObject'.

      * @throws IllegalArgumentException if the lists are null, empty or of different size; if the 'searchHelpName' or selectionMethod parameters are null

      */

     public List search(String searchHelpName, String selectionMethod, int maximumResults, List criteria, Class persistentObject, List javaFieldSelection, List sapFieldSelection) {

         int sapSearchHelpVOFieldCount = SapSearchHelpVO.getFieldCount();

         if (javaFieldSelection == null || sapFieldSelection == null || sapFieldSelection.size() == 0 || sapFieldSelection.size() > sapSearchHelpVOFieldCount)

         {

             throw new IllegalArgumentException("Field lists should not be null, should contain at least 1, and max. " + sapSearchHelpVOFieldCount + " elements");

         }

         if (javaFieldSelection.size() != sapFieldSelection.size()) {

             throw new IllegalArgumentException("For each item in the SAP field list, the java field list should have a value at the same position");

         }

         Map searchInput = new HashMap(5);

         if (searchHelpName == null) {

             throw new IllegalArgumentException("You have to specify the searchHelpName");

         }

         if (selectionMethod == null) {

             throw new IllegalArgumentException("You have to specify the selectionMethod");

         }

         searchInput.put("SEARCHHELPNAME", searchHelpName);

         searchInput.put("SEARCHHELPMETHOD", selectionMethod);

         searchInput.put("MAX_ROWS", String.valueOf(maximumResults));

         // Prepare SELECTIONCRITERIA table

         List selectionCriteria = new ArrayList(criteria.size());

         for (Iterator i = criteria.iterator(); i.hasNext();) {

             SearchCriterion criterion = (SearchCriterion) i.next();

             if (criterion != null) {

                 selectionCriteria.add(criterion.toMap());

             }

         }

         searchInput.put("SELECTIONCRITERIA", selectionCriteria);

         // Prepare FIELDLIST table

         searchInput.put("FIELDLIST", sapFieldSelection);

         // Execute search

         List results = (List) retrieve(SapSearchHelpVO.class, searchInput, null);

         // Process results, just return the internal value objects if no custom peristent class is specified

         if (persistentObject == null) {

             return results;

         }

         List persistentObjects = new ArrayList(results.size());

         for (Iterator i = results.iterator(); i.hasNext();) {

             SapSearchHelpVO vo = (SapSearchHelpVO) i.next();

             Object object = convertSearchHelpVO(vo, persistentObject, javaFieldSelection);

             if (object != null) {

                 persistentObjects.add(object);

             }

             i.remove();

         }

         return persistentObjects;

     }

     /**

      * Helper method to convert SearchHelpVO instances to instances of the same type as specified by 'persistentObject'.

      *

      * @param valueObject        search result (internal format)

      * @param persistentObject   class of the desired value object; must have a defined zero-args constructor

      * @param javaFieldSelection fields

      * @return instance of the same type as specified by 'persistentObject'.

      */

     private Object convertSearchHelpVO(SapSearchHelpVO valueObject, Class persistentObject, List javaFieldSelection) {

         Class valueObjectClass = valueObject.getClass();

         try {

             Object instance = persistentObject.newInstance();

             int i = 0;

             for (Iterator valueIterator = valueObject.iterator(); i < javaFieldSelection.size() && valueIterator.hasNext(); i++)

             {

                 Object value = valueIterator.next();

                 if (value == null) {

                     continue;

                 }

                 String fieldName = (String) javaFieldSelection.get(i);

                 Field field = persistentObject.getDeclaredField(fieldName);

                 field.setAccessible(true);

                 Object convertedValue = null;

                 if (Date.class.equals(field.getType())) {

                     try {

                         convertedValue = SAP_DATE_FORMATTER.parse((String) value);

                     } catch (ParseException e) {

                         log.warn("Unable to parse " + value + " as a date for field " + field.getName());

                     }

                 } else {

                     convertedValue = ConvertUtils.convert((String) value, field.getType());

                 }

                 field.set(instance, convertedValue);

             }

             return instance;

         } catch (InstantiationException e) {

             log.warn("Can not instantiate class " + persistentObject.getClass(), e);

         } catch (IllegalAccessException e) {

             log.warn("Can not set a field in class " + persistentObject.getClass() + " or get field in class " + valueObjectClass, e);

         } catch (NoSuchFieldException e) {

             log.warn("Can not find a field in class " + persistentObject + " or in class " + valueObjectClass, e);

         }

         return null;

     }

 }