/*
    * The SmartWeb Framework
    * Copyright (C) 2004-2006
    *
    * This library is free software; you can redistribute it and/or
    * modify it under the terms of the GNU Lesser General Public
    * License as published by the Free Software Foundation; either
    * version 2.1 of the License, or (at your option) any later version.
    *
   * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
   *
   * For further informations on the SmartWeb Framework please visit
   *
   *                        http://smartweb.sourceforge.net
   */
  package net.smartlab.web;
  
  import java.io.InputStream;
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Locale;
  import java.util.MissingResourceException;
  import java.util.Properties;
  
  import javax.servlet.ServletContext;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import net.smartlab.web.bean.Valorizer;
  
  import org.apache.commons.beanutils.locale.LocaleBeanUtilsBean;
  import org.apache.commons.beanutils.locale.LocaleConvertUtilsBean;
  import org.apache.commons.collections.FastHashMap;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.struts.Globals;
  import org.apache.struts.action.ActionErrors;
  import org.apache.struts.action.ActionForm;
  import org.apache.struts.action.ActionForward;
  import org.apache.struts.action.ActionMapping;
  import org.apache.struts.action.ActionMessage;
  import org.apache.struts.action.ActionMessages;
  import org.apache.struts.action.DynaActionForm;
  
  /**
   * This class represents the <i>controller </i> part of the <b>MVC </b> pattern.
   * Extend this class to provide a specific set of operations to be performed in
   * response of a user selection.
   * 
   * @author rlogiacco
   * @see org.apache.struts.action.Action
   * @uml.dependency supplier="net.smartlab.web.ActionException"
   * @uml.dependency supplier="net.smartlab.web.bean.Valorizer"
   */
  public abstract class Action extends org.apache.struts.action.Action {
  
  	/**
  	 * Identifies the default resource the request will be forwarded.
  	 */
  	public final static ActionForward DEFAULT_FORWARD = new ActionForward("default");
  
  	/**
  	 * Provides logging capabilities to the action.
  	 */
  	protected final Log logger = LogFactory.getLog(this.getClass());
  
  
  	/**
  	 * This method performs some common operations then redirects control to the
  	 * abstract <code>execute</code>.
  	 * 
  	 * @see org.apache.struts.action.Action#execute(org.apache.struts.action.ActionMapping,
  	 *      org.apache.struts.action.ActionForm,
  	 *      javax.servlet.http.HttpServletRequest,
  	 *      javax.servlet.http.HttpServletResponse)
  	 */
  	public ActionForward execute(ActionMapping mapping, ActionForm form, HttpServletRequest request,
  			HttpServletResponse response) throws Exception {
  		if (logger.isDebugEnabled()) {
  			logger.debug("execute(" + mapping.getPath() + ") - start");
  		}
  		ActionForward forward = null;
  		if (super.isCancelled(request)) {
  			if (logger.isDebugEnabled()) {
  				logger.debug("execute(" + mapping.getPath() + ") - cancel");
  			}
  			forward = this.cancel(form, request, response, mapping);
  			if (forward == DEFAULT_FORWARD) {
  				return mapping.getInputForward();
  			} else {
  				return forward;
 			}
 		}
 		forward = this.execute(form, request, response, mapping);
 		try {
 			if (request.getAttribute(Globals.ERROR_KEY) != null && forward == DEFAULT_FORWARD) {
 				if (logger.isDebugEnabled()) {
 					logger.debug("execute(" + mapping.getPath() + ") - errors");
 					if (logger.isTraceEnabled()) {
 						logger.trace("   " + request.getAttribute(Globals.ERROR_KEY));
 					}
 				}
 				return mapping.getInputForward();
 			}
 			return forward;
 		} finally {
 			if (logger.isTraceEnabled()) {
 				logger.trace("   forward = " + forward);
 			}
 		}
 	}
 
 	/**
 	 * Implement this method to provide a custom response to a user input.
 	 * 
 	 * @param form the html form submitted with this request.
 	 * @param request the user request.
 	 * @param response the representation of the response channel.
 	 * @param mapping the system control mapping.
 	 * @return the name of a defined global or local forward.
 	 * @throws Exception if something unexpected happend during the request
 	 *         execution.
 	 */
 	protected abstract ActionForward execute(ActionForm form, HttpServletRequest request, HttpServletResponse response,
 			ActionMapping mapping) throws Exception;
 
 	/**
 	 * Describes the operations sequence to be performed upon cancellation of a
 	 * form or wizard returning the mapping to redirect to. By default this
 	 * method simply does nothing more than redirecting to the
 	 * <code>input</code> path.
 	 * 
 	 * @param form the html form submitted with this request.
 	 * @param request the user request.
 	 * @param response the representation of the response channel.
 	 * @param mapping the system control mapping.
 	 * @return the name of a defined global or local forward.
 	 * @throws Exception if something unexpected happend during the request
 	 *         execution.
 	 */
 	protected ActionForward cancel(ActionForm form, HttpServletRequest request, HttpServletResponse response,
 			ActionMapping mapping) throws Exception {
 		return DEFAULT_FORWARD;
 	}
 
 	/**
 	 * Valorizes a <code>bean</code> instance with the values providen with
 	 * the user submitted html form. This method uses an improved version of the
 	 * introspection paradigm to discover properties bindings.
 	 * 
 	 * @param form the user submitted html form containing the values to be
 	 *        read.
 	 * @param bean the bean instance to be valorized.
 	 * @param locale the user locale for values parsing.
 	 * @throws ActionException if the valorization fails, usually due to
 	 *         inconsistencies between the bean and the submitted form.
 	 */
 	protected void valorize(ActionForm form, Object bean, Locale locale) throws ActionException {
 		try {
 			if (logger.isDebugEnabled()) {
 				logger.debug("valorize(" + form + ", " + bean + ") - start");
 			}
 			// FIXME
 			// this.getConverter(locale).copyProperties(bean, form);
 			Valorizer.copy(form, bean, locale);
 		} catch (Exception e) {
 			logger.debug("valorize(" + form + ", " + bean + ") - error", e);
 			throw new ActionException("action.error.valorize", e);
 		}
 	}
 
 	/**
 	 * Populates, or prevalorizes, an html form with the values of a
 	 * <code>bean</code> instance . This method uses an improved version of
 	 * the introspection paradigm to discover properties bindings.
 	 * 
 	 * @param form the form to be populated.
 	 * @param bean the bean instance containing the values to be written in the
 	 *        form.
 	 * @param locale the user locale for values parsing.
 	 * @throws ActionException if the valorization fails, usually due to
 	 *         inconsistencies between the bean and the submitted form.
 	 */
 	protected void populate(ActionForm form, Object bean, Locale locale) throws ActionException {
 		try {
 			if (logger.isDebugEnabled()) {
 				logger.debug("populate(" + form + ", " + bean + ") - start");
 			}
 			// FIXME
 			// this.getConverter(locale).copyProperties(form,bean);
 			Valorizer.copy(bean, form, locale);
 		} catch (Exception e) {
 			logger.debug("populate(" + form + ", " + bean + ") - error", e);
 			throw new ActionException("action.error.populate", e);
 		}
 	}
 
 	/**
 	 * @TODO documentation
 	 * @param locale
 	 * @return
 	 */
 	private LocaleBeanUtilsBean getConverter(Locale locale) {
 		LocaleConvertUtilsBean converter = new LocaleConvertUtilsBean() {
 			protected FastHashMap create(Locale locale) {
 				FastHashMap converter = super.create(locale);
 				converter.setFast(false);
 				// FIXME add converters
 				converter.setFast(true);
 				return converter;
 			}
 		};
 		converter.setDefaultLocale(locale);
 		return new LocaleBeanUtilsBean(converter);
 	}
 
 	/**
 	 * Ensures the specified html form has all its fields resetted to their
 	 * initial value.
 	 * 
 	 * @param form the form to be cleaned up.
 	 * @param request the user request.
 	 * @param mapping the system control mapping.
 	 */
 	public void reset(ActionForm form, HttpServletRequest request, ActionMapping mapping) {
 		if (form instanceof DynaActionForm) {
 			((DynaActionForm)form).initialize(mapping);
 		} else {
 			form.reset(mapping, request);
 		}
 	}
 
 	/**
 	 * TODO documentation
 	 * 
 	 * @param request
 	 * @return
 	 */
 	protected boolean hasErrors(HttpServletRequest request) {
 		return request.getAttribute(Globals.ERROR_KEY) != null;
 	}
 
 	/**
 	 * TODO documentation
 	 * 
 	 * @param message
 	 * @param request
 	 */
 	protected void addError(ActionMessage message, HttpServletRequest request) {
 		this.addError(ActionMessages.GLOBAL_MESSAGE, message, request);
 	}
 
 	/**
 	 * TODO documentation
 	 * 
 	 * @param property
 	 * @param message
 	 * @param request
 	 */
 	protected void addError(String property, ActionMessage message, HttpServletRequest request) {
 		ActionErrors errors = (ActionErrors)request.getAttribute(Globals.ERROR_KEY);
 		if (errors == null) {
 			errors = new ActionErrors();
 			request.setAttribute(Globals.ERROR_KEY, errors);
 		}
 		errors.add(property, message);
 	}
 
 	/**
 	 * TODO documentation
 	 * 
 	 * @param name
 	 * @param request
 	 * @return
 	 */
 	public boolean isChecked(String name, HttpServletRequest request) {
 		if ("on".equalsIgnoreCase(request.getParameter("group"))
 				|| "true".equalsIgnoreCase(request.getParameter("group"))
 				|| "yes".equalsIgnoreCase(request.getParameter("group"))) {
 			return true;
 		} else {
 			return false;
 		}
 	}
 
 	/**
 	 * TODO documentation
 	 * 
 	 * @return
 	 */
 	protected ServletContext getServletContext() {
 		return super.getServlet().getServletContext();
 	}
 
 	/**
 	 * TODO documentation
 	 * 
 	 * @param path
 	 * @return
 	 */
 	protected String getRealPath(String path) {
 		return this.getServletContext().getRealPath(path);
 	}
 
 	/**
 	 * TODO documentation
 	 * 
 	 * @return
 	 */
 	protected Properties getProperties() {
 		Class type = this.getClass();
 		List inputs = new ArrayList();
 		Properties result = new Properties();
 		while (type.getSuperclass().isAssignableFrom(Action.class)) {
 			try {
 				InputStream in = this.getClass().getResourceAsStream(this.getClass().getName() + ".prop");
 				inputs.add(in);
 			} catch (Exception e) {
 				if (logger.isDebugEnabled()) {
 					logger.debug("getProperties() - descend", e);
 				}
 			}
 			type = type.getSuperclass();
 		}
 		Iterator iterator = inputs.iterator();
 		while (iterator.hasNext()) {
 			try {
 				InputStream in = (InputStream)iterator.next();
 				Properties properties = new Properties();
 				properties.load(in);
 				result.putAll(properties);
 			} catch (Exception e) {
 				if (logger.isDebugEnabled()) {
 					logger.debug("getProperties() - load", e);
 				}
 			}
 		}
 		throw new MissingResourceException("No properties defined for action", this.getClass().getName(), null);
 	}
 }