/**
 * Copyright (c) 2009--2014 Red Hat, Inc.
 *
 * This software is licensed to you under the GNU General Public License,
 * version 2 (GPLv2). There is NO WARRANTY for this software, express or
 * implied, including the implied warranties of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. You should have received a copy of GPLv2
 * along with this software; if not, see
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
 *
 * Red Hat trademarks are not licensed under GPLv2. No permission is
 * granted to use or replicate Red Hat trademarks that are incorporated
 * in this software or its documentation.
 */
package com.redhat.rhn.frontend.action.systems;

import com.redhat.rhn.common.validator.ValidatorError;
import com.redhat.rhn.frontend.struts.RequestContext;
import com.redhat.rhn.frontend.struts.RhnAction;
import com.redhat.rhn.frontend.struts.RhnHelper;
import com.redhat.rhn.frontend.struts.RhnValidationHelper;
import com.redhat.rhn.frontend.struts.StrutsDelegate;
import com.redhat.rhn.manager.system.BaseSystemOperation;

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.DynaActionForm;

import java.util.HashMap;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * BaseSystemEditAction - base class for editing a System
 * @version $Rev: 1 $
 */
public abstract class BaseSystemEditAction extends RhnAction {

    /** {@inheritDoc} */
    public final ActionForward execute(ActionMapping mapping,
                                  ActionForm formIn,
                                  HttpServletRequest request,
                                  HttpServletResponse response) {
        String forwardname = RhnHelper.DEFAULT_FORWARD;
        DynaActionForm form = (DynaActionForm) formIn;
        RequestContext requestContext = new RequestContext(request);
        BaseSystemOperation cmd = getOperation(requestContext);

        StrutsDelegate strutsDelegate = getStrutsDelegate();

        request.setAttribute(RequestContext.SYSTEM, cmd.getServer());
        Map<String, Object> params = new HashMap<String, Object>();
        params.put(RequestContext.SID, cmd.getServer().getId());


        if (isSubmitted(form)) {
            ActionErrors errors = RhnValidationHelper.validateDynaActionForm(
                    this, form);

            if (!errors.isEmpty()) {
                strutsDelegate.saveMessages(request, errors);
            }
            else {
                ValidatorError ve = processFormValues(form, cmd);
                if (ve != null) {
                    ValidatorError[] verr = {ve};
                    strutsDelegate.saveMessages(request,
                            RhnValidationHelper.validatorErrorToActionErrors(verr));
                }
                else {
                    cmd.store();
                    createSuccessMessage(request, getSuccessKey(), null);
                    forwardname = getSuccessForward();
                }
            }
        }

        // Whether we processed the form submission or not, we need to
        // set up the form again for display.
        setupFormValues(requestContext, form, cmd);
        return strutsDelegate.forwardParams(mapping.findForward(forwardname), params);
    }

    protected abstract BaseSystemOperation getOperation(RequestContext ctx);

    /**
     * 'Overrideable' method for baseclasses that require a
     * different action forward.  This currently returns "default".
     * @return String "default" that can be overridden
     */
    protected String getSuccessForward() {
        return "success";
    }

    /**
     * Process the values from the form. This is called when the form is
     * submitted.  This is the 'submit' side of the action.
     * @param form to process
     * @param cmd to execute
     * @return ValidatorError if something failed.
     */
    protected abstract ValidatorError processFormValues(DynaActionForm form,
            BaseSystemOperation cmd);

    protected abstract String getSuccessKey();

    /**
     * Setup the form values and other attributes necessary for the
     * action to render.  This is where you pre-populate the form values
     * on the 'setup' side of the action.
     * @param ctx
     * @param form
     * @param cmd
     */
    protected abstract void setupFormValues(RequestContext ctx, DynaActionForm form,
            BaseSystemOperation cmd);

}