DefaultDataBeanMapper

package org.kuali.student.common.assembly.transform;

import java.beans.BeanInfo;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Field;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.sql.Time;
import java.sql.Timestamp;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.Map.Entry;

import org.kuali.student.common.assembly.data.Data;
import org.kuali.student.common.assembly.data.Metadata;
import org.kuali.student.common.assembly.data.Data.DataType;
import org.kuali.student.common.assembly.data.Data.Key;
import org.kuali.student.common.assembly.data.Data.Property;
import org.kuali.student.common.assembly.data.Data.StringKey;


public class DefaultDataBeanMapper implements DataBeanMapper {
	public static DataBeanMapper INSTANCE = new DefaultDataBeanMapper();

	/* (non-Javadoc)
	 * @see org.kuali.student.core.assembly.data.DataBeanMapper#convertFromBean(java.lang.Object)
	 */
	public Data convertFromBean(Object value) throws Exception{
		 Data result = new Data();

	        if (value != null) {
                BeanInfo info = Introspector.getBeanInfo(value.getClass());
                PropertyDescriptor[] properties = info.getPropertyDescriptors();

                for (PropertyDescriptor pd : properties) {
                    String propKey = pd.getName();
                    Object propValue = pd.getReadMethod().invoke(value, (Object[]) null);

                    if ("attributes".equals(propKey)){
                    	setDataAttributes(result, propValue);
                    } else {
	                    setDataValue(result, propKey, propValue);
                    }
                }
	        }

		return result;
	}

	/* (non-Javadoc)
	 * @see org.kuali.student.core.assembly.data.DataBeanMapper#convertFromData(org.kuali.student.core.assembly.data.Data, java.lang.Class)
	 */
	public Object convertFromData(Data data, Class<?> clazz, Metadata metadata) throws Exception{
		Object result = null;

		result = clazz.newInstance();
        BeanInfo info = Introspector.getBeanInfo(result.getClass());
        PropertyDescriptor[] properties = info.getPropertyDescriptors();

        PropertyDescriptor attrProperty = null;

        Set<Key> staticProperties = new HashSet<Key>();
		for (PropertyDescriptor pd : properties) {
			if ("attributes".equals(pd.getName())){
				//Dynamic attributes will be handled later
				attrProperty = pd;
			} else {
	            StringKey propKey = new StringKey(pd.getName());
	            Object propValue = data.get(propKey);

	            //Process a nested object structure or list
	            if (propValue instanceof Data){
	            	clazz.getFields();
	            	if(metadata!=null){
	            		if(DataType.LIST.equals(metadata.getDataType())){
	            			propValue = convertNestedData((Data)propValue, clazz.getDeclaredField(propKey.toString()),metadata.getProperties().get("*"));
	            		}else{
	            			propValue = convertNestedData((Data)propValue, clazz.getDeclaredField(propKey.toString()),metadata.getProperties().get(propKey.toString()));
	            		}
	            	}
	            	else{
	            		propValue = convertNestedData((Data)propValue, clazz.getDeclaredField(propKey.toString()),null);
	            	}
	            }else if(metadata!=null&&propValue==null){
	            	Metadata fieldMetadata = metadata.getProperties().get(propKey.toString());
	            	if(fieldMetadata != null && fieldMetadata.getDefaultValue() != null){
	            		propValue = fieldMetadata.getDefaultValue().get();
	            	}
	            }

	    		//Set the bean property
	    		if(pd.getWriteMethod() != null & propValue != null){
	    			if(!(propValue instanceof List) && pd.getPropertyType().isAssignableFrom(List.class)){
	    				ArrayList<Object> list = new ArrayList<Object>(1);
	    				list.add(propValue);
	    				pd.getWriteMethod().invoke(result, list);
	    			}else{
	    				pd.getWriteMethod().invoke(result, new Object[] {propValue});
	    			}
	            }

	    		//Hold onto the property so we know it is not dynamic
	    		staticProperties.add(propKey);
			}
		}

		//Any fields not processed above doesn't exist as properties for the bean and
		//will be set as dynamic attributes.
		Set<Key> keySet = data.keySet();
		if (keySet != null && attrProperty != null){
			Map<String,String> attributes = new HashMap<String,String>();
            for (Key k : keySet) {
				String keyString = k.toString();
				//Obtain the dynamic flag from the dictionary
				if(metadata==null){
					if (!staticProperties.contains(k) && data.get(k) != null && !keyString.startsWith("_run")){
						attributes.put((String)k.get(),data.get(k).toString());
					}
				}
				else {
				    if ((! staticProperties.contains(k)) &&
				        (null != data.get(k)) &&
				        (! keyString.startsWith("_run")) &&
				        (null != metadata.getProperties().get(keyString)) &&
				        (metadata.getProperties().get(keyString).isDynamic()))
				    {
                        attributes.put((String) k.get(), data.get(k).toString());
					}
				}
			}
            if (attrProperty.getWriteMethod() != null) {
                attrProperty.getWriteMethod().invoke(result, new Object[] {attributes});
            }
		}

		return result;
	}


	/**
	 * Processes a nested data map, it checks to see if the data should be converted to
	 * a list structure or simply be processed as a nested complex object structure.
	 *
	 * @param data
	 * @param propField
	 * @return
	 * @throws Exception
	 */
	protected Object convertNestedData(Data data, Field propField, Metadata metadata) throws Exception{
		Object result = null;

		Class<?> propClass = propField.getType();
		if ("java.util.List".equals(propClass.getName())){
			//Get the generic type for the list
			ParameterizedType propType = (ParameterizedType)propField.getGenericType();
			Type itemType = propType.getActualTypeArguments()[0];


			List<Object> resultList = new ArrayList<Object>();
			for(Iterator<Property> listIter = data.realPropertyIterator(); listIter.hasNext();){
				Property listItem = listIter.next();
				Object listItemValue = listItem.getValue();
				if (listItemValue instanceof Data ){
					Data listItemData = (Data)listItemValue;
					Boolean isDeleted = listItemData.query("_runtimeData/deleted");
					if (isDeleted == null || !isDeleted){
						if(metadata!=null){
							listItemValue = convertFromData((Data)listItemValue, (Class<?>)itemType, metadata.getProperties().get("*"));
						}else{
							listItemValue = convertFromData((Data)listItemValue, (Class<?>)itemType, null);
						}
						resultList.add(listItemValue);
					}
				} else {
					resultList.add(listItemValue);
				}
			}

			result = resultList;
		} else {
			result = convertFromData(data, propClass,metadata);
		}

		return result;
	}

	/**
	 * Used to set a simple property value into the data object.
	 * @param data
	 * @param propertyKey
	 * @param value
	 *
	 */
	protected void setDataValue(Data data, String propertyKey, Object value) throws Exception{
		if (isPropertyValid(value)){
			if (value instanceof Boolean){
				data.set(propertyKey, (Boolean)value);
			} else if (value instanceof Date){
				data.set(propertyKey, (Date)value);
			} else if (value instanceof Integer){
				data.set(propertyKey, (Integer)value);
			} else if (value instanceof Double){
				data.set(propertyKey, (Double)value);
			} else if (value instanceof Float){
				data.set(propertyKey, (Float)value);
			} else if (value instanceof Long) {
				data.set(propertyKey, (Long)value);
			} else if (value instanceof Short){
				data.set(propertyKey, (Short)value);
			} else if (value instanceof String){
				data.set(propertyKey, (String)value);
			} else if (value instanceof Timestamp){
				data.set(propertyKey, (Timestamp)value);
			} else if (value instanceof Time){
				data.set(propertyKey, (Time)value);
			} else if (value instanceof Collection){
				data.set(propertyKey, getCollectionData(value));
			} else {
				Data dataValue = convertFromBean(value);
				data.set(propertyKey, dataValue);
			}
		}

	}

	/**
	 * This process the attributes map and sets the attribute key/value pairs into the Data map
	 *
	 * @param data
	 * @param value
	 */
	protected void setDataAttributes(Data data, Object value) {
		@SuppressWarnings("unchecked")
		Map<String, String> attributes = (Map<String, String>)value;

		for (Entry<String, String> entry:attributes.entrySet()){
			if("false".equals(entry.getValue())||"true".equals(entry.getValue())){
				data.set(entry.getKey(), Boolean.valueOf(entry.getValue()));
			}else{
				data.set(entry.getKey(), entry.getValue());
			}
		}
	}

	/**
	 * Used to set a list item value into the data object.
	 *
	 * @param data
	 * @param value
	 */
	protected void setDataListValue(Data data, Object value) throws Exception{
		if (isPropertyValid(value)){
			if (value instanceof Boolean){
				data.add((Boolean)value);
			} else if (value instanceof Date){
				data.add((Date)value);
			} else if (value instanceof Integer){
				data.add((Integer)value);
			} else if (value instanceof Double){
				data.add((Double)value);
			} else if (value instanceof Float){
				data.add((Float)value);
			} else if (value instanceof Long) {
				data.add((Long)value);
			} else if (value instanceof Short){
				data.add((Short)value);
			} else if (value instanceof String){
				data.add((String)value);
			} else if (value instanceof Timestamp){
				data.add((Timestamp)value);
			} else if (value instanceof Time){
				data.add((Time)value);
			} else if (value instanceof Collection){
				data.add(getCollectionData(value));
			} else {
				Data dataValue = convertFromBean(value);
				data.add(dataValue);
			}
		}
	}

	/**
	 * Returns a data map object representing a collection
	 *
	 * @param value
	 * @return
	 * @throws Exception
	 */
	protected Data getCollectionData(Object value) throws Exception{
		Data result = new Data();

		if (value instanceof List){
			List<?> valueList = (List<?>)value;
			for (int i=0;i<valueList.size();i++){
				Object itemValue = valueList.get(i);
				setDataListValue(result, itemValue);
			}
		} else {
			Collection<?> valueCollection = (Collection<?>)value;
			for (Object o:valueCollection){
				setDataListValue(result, o);
			}
		}

		return result;
	}

	protected boolean isPropertyValid(Object value){
		boolean isValid = false;

		if (value != null){
			Class<?> clazz = value.getClass();
			isValid = !(clazz.isArray() || clazz.isAnnotation() || value instanceof Class);
		}

		return isValid;
	}
}