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/* 
 * This file is part of the Echo Web Application Framework (hereinafter "Echo").
 * Copyright (C) 2002-2012 NextApp, Inc.
 *
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 */

package nextapp.echo.webcontainer;

import javax.servlet.GenericServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

/**
 * A WebSocket based implementation of AbstractConnection
 * 
 * @author Miro Yozov
 */
public class WebSocketConnection extends AbstractConnection {

    /**
     * Prefix to use for UserInstanceContainer
     * HttpSession keys.
     */
    private static final String WEB_SOCKET_SESSION_KEY_PREFIX = "EchoWebSocket";

    static String getWebSocketSessionKey(GenericServlet servlet) {
        return WEB_SOCKET_SESSION_KEY_PREFIX + ":" + servlet.getServletName();
    }

    private final String protocol;
    private ApplicationWebSocket applicationWebSocket = null;

    public WebSocketConnection(HttpServlet servlet, HttpServletRequest request, String protocol) {
        super(servlet, request);
        this.protocol = protocol;
        HttpSession session = request.getSession();
        if (session != null) {
            applicationWebSocket = (ApplicationWebSocket) session.getAttribute(getWebSocketSessionKey(this.servlet));
        }
    }

    protected void storeUiid() {
        String uiidParam = request.getParameter(WebContainerServlet.USER_INSTANCE_ID_PARAMETER);
        if (uiidParam != null) {
            uiid = uiidParam;
        }
    }

    public String getProtocol() {
        return protocol;
    }

    public ApplicationWebSocket getApplicationWebSocket() {
        return applicationWebSocket;
    }

    public void preInit(UserInstanceContainer userInstanceContainer) {
        this.userInstanceContainer = userInstanceContainer;
        userInstance = userInstanceContainer.getUserInstanceById(uiid);
        final HttpSession session = request.getSession();
        session.setAttribute(getUserInstanceContainerSessionKey(this.servlet), userInstanceContainer);
    }

    public void postInit(ApplicationWebSocket appws) {
        if (this.userInstanceContainer == null) {
            throw new Error("WebSocketConnection is not preinitialized!");
        }
        applicationWebSocket = appws;
        final HttpSession session = request.getSession();
        session.setAttribute(getWebSocketSessionKey(this.servlet), this.applicationWebSocket);
        userInstance.initWebSocket(this);
    }

    /**
     * Determines if the WebSocketConnection has been initialized, i.e.,
     * whether its preInit() and postInit() methods has
     * been invoked.
     * 
     * @return true if the WebSocketConnection is initialized
     */
    public boolean isReady() {
        return userInstanceContainer != null && userInstance != null;
    }
}