/*
    * This file is a part of CAST project.
    * (c) Copyright 2007, AGH University of Science & Technology
    * https://caribou.iisg.agh.edu.pl/trac/cast
    *
    * Licensed under the Eclipse Public License, Version 1.0 (the "License").
    * You may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    * http://www.eclipse.org/legal/epl-v10.html
   */
  /*
   * File: ModelElement.java
   * Created: 2007-00-00
   * Author: awos
   * $Id: ModelElement.java 3020 2009-07-17 14:41:19Z kpietak $
   */
  
  package pl.edu.agh.cast.model.visual.backward;
  
  import java.beans.PropertyChangeEvent;
  import java.beans.PropertyChangeListener;
  import java.io.Serializable;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.LinkedList;
  import java.util.List;
  import java.util.SortedMap;
  import java.util.TreeMap;
  
  import pl.edu.agh.cast.backward.resources.xml.AttributeValuesConverter;
  import pl.edu.agh.cast.data.model.property.IPropertyChangeProvider;
  import pl.edu.agh.cast.data.model.property.PropertyChangeProviderHelper;
  import pl.edu.agh.cast.model.attributes.Attribute;
  import pl.edu.agh.cast.model.attributes.AttributeManager;
  import pl.edu.agh.cast.model.attributes.AttributeMergePolicy;
  import pl.edu.agh.cast.model.attributes.AttributeValue;
  import pl.edu.agh.cast.model.mapper.Mappable;
  import pl.edu.agh.cast.util.Messages;
  
  import com.thoughtworks.xstream.annotations.XStreamAlias;
  import com.thoughtworks.xstream.annotations.XStreamAsAttribute;
  import com.thoughtworks.xstream.annotations.XStreamConverter;
  import com.thoughtworks.xstream.annotations.XStreamOmitField;
  
  /**
   * An abstract class for a visual model element. Provides implementation for property change support.
   *
   * @author AGH CAST Team
   */
  public abstract class ModelElement implements Serializable, IPropertyChangeProvider, AttributeValueContainer,
          PropertyChangeListener {
  
  	private static final long serialVersionUID = 4933221188249730849L;
  
  	/**
  	 * Id of an event informing of attribute value changes in model elements. In the {@link PropertyChangeEvent}, old
  	 * value is of type {@link AttributeValue}, and new value is the {@link AttributeValue#getValue()} of the new value.
  	 */
  	public static final String ATTRIBUTE_CHANGE = "ModelElement.attributeValue"; //$NON-NLS-1$
  
  	/**
  	 *
  	 */
  	@XStreamAlias("attributeValues")
  	@XStreamConverter(AttributeValuesConverter.class)
  	protected SortedMap<Attribute, AttributeValue> attributeValues;
  
  	@XStreamAlias("mid")
  	@XStreamAsAttribute
  	private long mid;
  
  	@XStreamAlias("saved")
  	@XStreamAsAttribute
  	private boolean saved;
  
  	@XStreamOmitField
  	private transient PropertyChangeProviderHelper pcpHelper;
  
  	/**
  	 * Initializes new instance.
  	 */
  	protected ModelElement() {
  		pcpHelper = new PropertyChangeProviderHelper(this);
  		attributeValues = new TreeMap<Attribute, AttributeValue>();
  	}
  
  	/**
  	 * {@inheritDoc}
  	 *
  	 * @see pl.edu.agh.cast.model.visual.backward.AttributeValueContainer#getAttributeManager()
  	 */
  	public abstract AttributeManager getAttributeManager();
  
  	public long getMid() {
  		return mid;
  	}
  
  	public void setMid(long mid) {
  		this.mid = mid;
 	}
 
 	public boolean isSaved() {
 		return saved;
 	}
 
 	public void setSaved(boolean saved) {
 		this.saved = saved;
 	}
 
 	protected Object readResolve() {
 		pcpHelper = new PropertyChangeProviderHelper(this);
 		return this;
 	}
 
 	// BEGIN Property change support
 
 	/**
 	 * {@inheritDoc}
 	 *
 	 * @see pl.edu.agh.cast.data.model.property.IPropertyChangeProvider#addPropertyChangeListener(java.beans.PropertyChangeListener)
 	 */
 	public void addPropertyChangeListener(PropertyChangeListener l) {
 		pcpHelper.addPropertyChangeListener(l);
 	}
 
 	/**
 	 * {@inheritDoc}
 	 *
 	 * @see pl.edu.agh.cast.data.model.property.IPropertyChangeProvider
 	 *      #removePropertyChangeListener(java.beans.PropertyChangeListener)
 	 */
 	public void removePropertyChangeListener(PropertyChangeListener l) {
 		pcpHelper.removePropertyChangeListener(l);
 	}
 
 	/**
 	 * Notifies about property change.
 	 *
 	 * @param property
 	 *            name of the property
 	 * @param oldValue
 	 *            old value of the property
 	 * @param newValue
 	 *            new value of the property
 	 */
 	protected void firePropertyChange(String property, Object oldValue, Object newValue) {
 		pcpHelper.firePropertyChange(property, oldValue, newValue);
 	}
 
 	// END Property change support
 
 	// BEGIN Attribute handling
 
 	/**
 	 * {@inheritDoc}
 	 *
 	 * @see pl.edu.agh.cast.model.visual.backward.AttributeValueContainer#getAttributeValue(java.lang.String)
 	 */
 	public AttributeValue getAttributeValue(String name) {
 		Attribute attribute = getAttributeManager().getAttribute(name);
 		if (attributeValues.containsKey(attribute)) {
 			return attributeValues.get(attribute);
 		} else {
 			// return a temporary value object with attribute's default value
 			return new AttributeValue(attribute, attribute.getDefaultValue());
 		}
 	}
 
 	/**
 	 * Checks if an attribute value may be set.
 	 *
 	 * @param name
 	 *            name of the attribute
 	 * @return <code>true</code> if attribute value may be set
 	 */
 	public boolean isAttributeSettable(String name) {
 		Attribute attribute = getAttributeManager().getAttribute(name);
 		return attribute.isEditable() || getAttributeValue(name).getValue() == null;
 	}
 
 	/**
 	 * {@inheritDoc}
 	 *
 	 * @see pl.edu.agh.cast.model.visual.backward.AttributeValueContainer#setAttributeValue(java.lang.String, java.lang.Object)
 	 */
 	public void setAttributeValue(String name, Object newValue) {
 		setAttributeValue(name, newValue, null);
 	}
 
 	/**
 	 * {@inheritDoc}
 	 *
 	 * @see pl.edu.agh.cast.model.visual.backward.AttributeValueContainer#setAttributeValue(java.lang.String, java.lang.Object,
 	 *      pl.edu.agh.cast.model.attributes.AttributeMergePolicy)
 	 */
 	public void setAttributeValue(String name, Object newValue, AttributeMergePolicy policy) {
 
 		Attribute attribute = getAttributeManager().getAttribute(name);
 
 		if (!isAttributeSettable(name)) {
 			// non-editable attributes can be assigned values only once
 			// this is more less the same as assigning to a null
 			throw new UnsupportedOperationException(Messages.ModelElementPropertyHolder_0);
 		} else {
 			Object oldVal = getAttributeValue(name);
 			Object newVal = newValue;
 			if (policy != null) {
 				newVal = policy.mergeValues(attribute, oldVal == null ? null : ((AttributeValue)oldVal)
 				        .getValue(), newValue);
 			}
 			attributeValues.put(attribute, new AttributeValue(attribute, newVal));
 
 			// XXX [tmilos] inconsistent types:
 			// (oldValue.getClass() == AttributeValue.class)
 			// (newValue.getClass() != AttributeValue.class)
 			firePropertyChange(ATTRIBUTE_CHANGE, oldVal, newVal);
 		}
 	}
 
 	/**
 	 * {@inheritDoc}
 	 *
 	 * @see pl.edu.agh.cast.model.visual.backward.AttributeValueContainer#isAttributeEditable(java.lang.String)
 	 */
 	public boolean isAttributeEditable(String attributeName) {
 		Attribute attribute = getAttributeManager().getAttribute(attributeName);
 		return attribute.isEditable();
 	}
 
 	/**
 	 * {@inheritDoc}
 	 *
 	 * @see pl.edu.agh.cast.model.visual.backward.AttributeValueContainer#getAllValues()
 	 */
 	public List<AttributeValue> getAllValues() {
 		Collection<Attribute> attributes = getAttributeManager().getAttributes();
 
 		// Update local property value collection
 		for (Attribute attribute : attributes) {
 			if (!attributeValues.containsKey(attribute)) {
 				// populate unset attributes with default values
 				setAttributeValue(attribute.getName(), getAttributeValue(attribute.getName()).getValue());
 			}
 		}
 
 		// Remove properties which names are not registered
 		Collection<Attribute> keySet = new LinkedList<Attribute>(attributeValues.keySet());
 		for (Attribute setAttribute : keySet) {
 			if (!attributes.contains(setAttribute)) {
 				removePropertyValue(setAttribute.getName());
 			}
 		}
 
 		return new ArrayList<AttributeValue>(attributeValues.values());
 	}
 
 	/**
 	 * {@inheritDoc}
 	 *
 	 * @see pl.edu.agh.cast.model.visual.backward.AttributeValueContainer#removePropertyValue(java.lang.String)
 	 */
 	public AttributeValue removePropertyValue(String name) {
 		// cannot use _attributeManager.getAttribute(name), because the property
 		// can be already unregistered
 		for (AttributeValue value : attributeValues.values()) {
 			if (value.getAttribute().getName().equals(name)) {
 				return attributeValues.remove(value.getAttribute());
 			}
 		}
 		return null;
 	}
 
 	/**
 	 * Copies attributes present in current model element to another model element.
 	 *
 	 * @param target
 	 *            {@link AttributeValueContainer} to copy to
 	 */
 	protected void copyAttributes(AttributeValueContainer target) {
 		for (AttributeValue value : attributeValues.values()) {
 			if (isAttributeSettable(value.getAttribute().getName())) {
 				target.setAttributeValue(value.getAttribute().getName(), value.getValue());
 			}
 		}
 	}
 
 	/**
 	 * {@inheritDoc}
 	 *
 	 * @see java.beans.PropertyChangeListener#propertyChange(java.beans.PropertyChangeEvent)
 	 */
 	public void propertyChange(PropertyChangeEvent evt) {
 		if (evt.getNewValue() == null && AttributeManager.ATTRIBUTE_REGISTRATION_STATUS.equals(evt.getPropertyName())) {
 			// attribute removed from the manager - remove stored value
 			removePropertyValue(((Attribute)evt.getOldValue()).getName());
 		}
 	}
 
 	/**
 	 * Registers this model elements to notifications from its attribute manager about changed properties.
 	 */
 	protected final void bindToAttributeManager() {
 		getAttributeManager().addPropertyChangeListener(this);
 	}
 
 	/**
 	 * Copies values of all {@link Attribute}s of <code>mappable</code> that are registered in this {@link ModelElement}
 	 * 's {@link AttributeManager}.
 	 *
 	 * If defined, the {@link Attribute#getDefaultMergePolicy()} policies are used in order to update particular
 	 * attribute value.
 	 *
 	 * @param mappable
 	 *            {@link Mappable} to copy attribute values' from
 	 */
 	public void copyAttributeValues(Mappable mappable) {
 
 		for (String attributeName : mappable.getAttributeNames()) {
 
 			// copy only values of registered attributes
 			if (getAttributeManager().isRegisteredId(attributeName) && isAttributeSettable(attributeName)) {
 
 				AttributeValue attributeValue = getAttributeValue(attributeName);
 				Object newValue = mappable.getAttribute(attributeName);
 
 				// if there is already a value then merge if a policy is set
 				if (attributeValue != null) {
 					Attribute attribute = attributeValue.getAttribute();
 					if (attribute.getDefaultMergePolicy() != null) {
 						Object oldValue = attributeValue == null ? null : attributeValue.getValue();
 						newValue = attribute.getDefaultMergePolicy().mergeValues(attribute, oldValue, newValue);
 					}
 				}
 
 				// modify the value
 				setAttributeValue(attributeName, newValue);
 			}
 
 		}
 
 	}
 
 	// END Attribute handling
 
 }