package net.sf.stitch.crud;
   
   import java.lang.reflect.Field;
   import java.lang.reflect.Method;
   import java.lang.reflect.Modifier;
   import java.util.Collection;
   import java.util.Collections;
   import java.util.LinkedHashMap;
   import java.util.Map;
  
  import javax.persistence.Entity;
  
  /**
   * <a href="http://en.wikipedia.org/wiki/Create%2C_read%2C_update_and_delete">CRUD</a>
   * Profile for an Entity class.
   * @author Logan Hutchinson
   */
  public class CrudEntity
  {
      /** package.EntityClass */
      private final String entityClassName;
      /** EntityClass */
      private final String entityShortName;
      /** entityClass */
      private final String entityPrefix;
  
      /** Seam Component Name of the EntityHome class related to the Entity. */
      private final String entityHome;
      /** Seam Component Name of the EntityQuery class related to the Entity. */
      private final String entityQuery;
  
      /** Collection of Fields/Getters for entity class */
      private final Map<String,CrudEntityProperty> entityFields;
  
      /**
       * Construct a new CrudProfile for a given entity class.
       * @param entityClassName
       */
      public CrudEntity (final String entityClassName) throws ClassNotFoundException
      {
          // Validate parameter...
          final Class<?> entityClass = Class.forName(entityClassName);
          if (!entityClass.isAnnotationPresent(Entity.class))
          {
              throw new IllegalArgumentException("CrudEntity may only be instantiated for a class annotated with @Entity");
          }
  
          //  Initialize object...
          this.entityClassName = entityClassName;
          this.entityShortName = entityClassName.substring(entityClassName.lastIndexOf('.') + 1);
          this.entityPrefix = Character.toLowerCase(entityShortName.charAt(0)) + entityShortName.substring(1);
          this.entityFields = buildEntityFields(entityClass);
  
          //  TODO:  Consider providing an annotation to override the defaults...
          this.entityHome = this.entityPrefix + "Home";
          this.entityQuery = this.entityPrefix + "List";
      }
  
      protected static boolean isGetter (final Method m)
      {
          return isBeanMethod(m, "get");
      }
  
      protected static boolean isSetter (final Method m)
      {
          return isBeanMethod(m, "set");
      }
  
      protected static boolean isBeanMethod (final Method m, final String prefix)
      {
          final String methodName = m.getName();
          return methodName.startsWith(prefix)
              && methodName.length() > prefix.length()
              && Character.isUpperCase(methodName.charAt(prefix.length()));
      }
      
      protected static String fieldNameFromXetter (final String methodName)
      {
          return Character.toLowerCase(methodName.charAt(3)) + methodName.substring(4);
      }
      
      private Map<String,CrudEntityProperty> buildEntityFields (final Class<?> entityClass)
      {
          final Map<String,CrudEntityProperty> fieldMap = new LinkedHashMap<String,CrudEntityProperty>();
          
          //  Iterate through all of the non-transient fields...
          for (final Field f : entityClass.getDeclaredFields())
          {
              final int fieldModifiers = f.getModifiers();
              if (!Modifier.isTransient(fieldModifiers))
              {
                  final String name = f.getName();
                  fieldMap.put(name, new CrudEntityProperty(f));
              }
          }
          //  Iterate through all of the methods looking for getters and setters...
          for (final Method m : entityClass.getDeclaredMethods())
          {
              final int methodModifiers = m.getModifiers();
             if (!Modifier.isStatic(methodModifiers))
             {
                 if (isGetter(m))
                 {
                     final String fieldName = fieldNameFromXetter(m.getName());
                     final CrudEntityProperty prop = fieldMap.get(fieldName);
                     if (null != prop)
                     {
                         prop.setGetter(m);
                     }
                 }
                 else if (isSetter(m))
                 {
                     final String fieldName = fieldNameFromXetter(m.getName());
                     final CrudEntityProperty prop = fieldMap.get(fieldName);
                     if (null != prop)
                     {
                         prop.setSetter(m);
                     }
                 }
             }
         }
 
         return fieldMap;
     }
 
     /**
      * @return Full class name for Entity (example: package.EntityClass).
      */
     public String getEntityClassName ()
     {
         return this.entityClassName;
     }
 
     /**
      * @return Short class name (no package) for Entity (example: EntityClass).
      */
     public String getEntityShortName ()
     {
         return this.entityShortName;
     }
 
     /**
      * @return Prefix for Seam Component Names and Variables related to Entity (example: entityClass).
      */
     public String getEntityPrefix ()
     {
         return this.entityPrefix;
     }
     
     /**
      * @return Seam Component Name of the EntityHome object related to the Entity.
      */
     public String getEntityHome ()
     {
         return this.entityHome;
     }
 
     /**
      * @return Seam Component Name of the EntityQuery object related to the Entity.
      */
     public String getEntityQuery ()
     {
         return this.entityQuery;
     }
 
     /**
      * @return Collection of Properties/Fields for the Entity.
      */
     public Collection<CrudEntityProperty> getEntityFields ()
     {
         return Collections.unmodifiableCollection(this.entityFields.values());
     }
 
     /**
      * Gets the resource bundle key for translating the entity class into a localized message. 
      * @return Typically, package.class
      */
     public String getMessageKey ()
     {
         return entityClassName;
     }
 }