/*
 * $Id$
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.struts2.jsf;

import javax.faces.context.FacesContext;
import javax.faces.event.PhaseEvent;
import javax.faces.event.PhaseId;
import javax.faces.event.PhaseListener;
import javax.faces.lifecycle.Lifecycle;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.util.logging.Logger;
import com.opensymphony.xwork2.util.logging.LoggerFactory;

/**
 * Provides common lifecycle phase methods needed by interceptors and results.
 */
public class FacesSupport {

    private static final String LIFECYCLE_KEY = "lifecycle";

    /** Log instance for each class */
    protected Logger log;

    /**
     * Marker key for the ActionContext to dictate whether to treat the request
     * as a JSF faces request and therefore process the Faces phases
     */
    protected static final String FACES_ENABLED = "facesEnabled";

    /** Initializes log instance for the instance object */
    protected FacesSupport() {
        log = LoggerFactory.getLogger(getClass());
    }

    /**
     * Gets the shared lifecycle for this request
     *
     * @return The lifecycle
     */
    private Lifecycle getLifecycle() {
        return (Lifecycle) ActionContext.getContext().get(LIFECYCLE_KEY);
    }

    /**
     * Sets the lifecycle for this request
     *
     * @param lifecycle
     *            The lifecycle
     */
    protected void setLifecycle(Lifecycle lifecycle) {
        ActionContext.getContext().put(LIFECYCLE_KEY, lifecycle);
    }

    /**
     * Informs phase listeners before a phase is executed
     *
     * @param facesContext
     *            The current faces context
     * @param phaseId
     *            The phase id about to be executed
     */
    protected void informPhaseListenersBefore(FacesContext facesContext,
            PhaseId phaseId) {
        Lifecycle lifecycle = getLifecycle();
        PhaseListener[] phaseListeners = lifecycle.getPhaseListeners();
        for (int i = 0; i < phaseListeners.length; i++) {
            PhaseListener phaseListener = phaseListeners[i];
            int listenerPhaseId = phaseListener.getPhaseId().getOrdinal();
            if (listenerPhaseId == PhaseId.ANY_PHASE.getOrdinal()
                    || listenerPhaseId == phaseId.getOrdinal()) {
                phaseListener.beforePhase(new PhaseEvent(FacesContext
                        .getCurrentInstance(), phaseId, lifecycle));
            }
        }

    }

    /**
     * Informs phase listeners after a phase is executed
     *
     * @param facesContext
     *            The current faces context
     * @param phaseId
     *            The phase id that was executed
     */
    protected void informPhaseListenersAfter(FacesContext facesContext,
            PhaseId phaseId) {
        Lifecycle lifecycle = getLifecycle();
        PhaseListener[] phaseListeners = lifecycle.getPhaseListeners();
        for (int i = 0; i < phaseListeners.length; i++) {
            PhaseListener phaseListener = phaseListeners[i];
            int listenerPhaseId = phaseListener.getPhaseId().getOrdinal();
            if (listenerPhaseId == PhaseId.ANY_PHASE.getOrdinal()
                    || listenerPhaseId == phaseId.getOrdinal()) {
                phaseListener.afterPhase(new PhaseEvent(FacesContext
                        .getCurrentInstance(), phaseId, lifecycle));
            }
        }

    }

    /**
     * Checks to see if the response has been completed. Mainly used for better
     * debugging messages.
     *
     * @param facesContext
     *            The current faces context
     * @param phase
     *            The phase id in execution
     * @param before
     *            Whether the phase has been executed or not
     * @return True if the response is complete
     */
    protected boolean isResponseComplete(FacesContext facesContext,
            String phase, boolean before) {
        boolean flag = false;
        if (facesContext.getResponseComplete()) {
            if (log.isDebugEnabled())
                log
                        .debug("exiting from lifecycle.execute in "
                                + phase
                                + " because getResponseComplete is true from one of the "
                                + (before ? "before" : "after") + " listeners");
            flag = true;
        }
        return flag;
    }

    /**
     * Checks to see the render phase should be executed next. Mainly used for
     * better debugging messages.
     *
     * @param facesContext
     *            The current faces context
     * @param phase
     *            The phase id in execution
     * @param before
     *            Whether the phase has been executed or not
     * @return True if the response is complete
     */
    protected boolean shouldRenderResponse(FacesContext facesContext,
            String phase, boolean before) {
        boolean flag = false;
        if (facesContext.getRenderResponse()) {
            if (log.isDebugEnabled())
                log.debug("exiting from lifecycle.execute in " + phase
                        + " because getRenderResponse is true from one of the "
                        + (before ? "before" : "after") + " listeners");
            flag = true;
        }
        return flag;
    }
}