/**
 * 
 */
package org.eclipse.papyrus.infra.core.resource;

import java.util.ArrayList;
import java.util.List;

/**
 * An exception encapsulating multiple exceptions. This exception is thrown when
 * an operation performed on several Models fails on one or more of these
 * models. The exception contains all the exceptions encoutered while opertating
 * on models.
 * 
 * @author cedric dumoulin
 * 
 */
public class ModelMultiException extends ModelException {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

	/**
	 * List of encountered exceptions.
	 */
	List<Throwable> encounteredExceptions = new ArrayList<Throwable>();

	/**
	 * List of identifiers corresponding to exceptions.
	 */
	List<Object> encounteredModels = new ArrayList<Object>();

	/**
	 * @return the encounteredExceptions
	 */
	public List<Throwable> getExceptions() {
		return encounteredExceptions;
	}

	/**
	 * Constructor.
	 * 
	 */
	public ModelMultiException() {
		super("Multiple exceptions");
	}

	/**
	 * Constructor.
	 * 
	 * @param message
	 */
	public ModelMultiException(String message) {
		super(message);
	}

	/**
	 * Return the first exception.
	 * 
	 * @see java.lang.Throwable#getCause()
	 * 
	 * @return
	 */
	@Override
	public Throwable getCause() {
		return (encounteredExceptions.size() > 0 ? encounteredExceptions.get(0) : null);
	}

	/**
	 * Return the message if any, or the message of the first exception.
	 * 
	 * @see java.lang.Throwable#getMessage()
	 * 
	 * @return
	 */
	@Override
	public String getMessage() {

		StringBuffer buffer = new StringBuffer();

		String message = super.getMessage();
		if(message != null)
			buffer.append(message).append('\n');

		buffer.append("----- exceptions : ----------\n");
		for(int i = 0; i < encounteredExceptions.size(); i++) {
			Throwable exception = encounteredExceptions.get(i);
			Object identifierMsg = encounteredModels.get(i);

			if(identifierMsg != null)
				buffer.append(identifierMsg.toString()).append(" : ");
			String msg = exception.getMessage();
			if(msg != null)
				buffer.append(msg).append('\n');
		}
		buffer.append("----------------------------- \n");

		return buffer.toString();
		// // Check for first exception
		// if( encounteredExceptions.size() > 1)
		// return encounteredExceptions.get(0).getMessage();
		//
		// // default
		// return null;
	}

	/**
	 * Add an exception to the list of exceptions.
	 * 
	 * @param exception
	 */
	public void addException(Throwable exception) {
		addException("unknown", exception);
	}

	/**
	 * Add an exception to the list of exceptions. Also record the corresponding
	 * model identifier if any.
	 * 
	 * @param exception
	 */
	public void addException(Object identifier, Throwable exception) {
		encounteredExceptions.add(exception);
		encounteredModels.add(identifier);
	}

	/**
	 * Return true if this MultiExceptions contains nested exceptions.
	 * 
	 * @return
	 */
	public boolean isNotEmpty() {
		return encounteredExceptions.size() != 0;
	}
}