AppEngineServiceContextFactory.java

/*
 * Copyright 2013 The Sculptor Project Team, including the original 
 * author or authors.
 * 
 * Licensed 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.sculptor.framework.context;

import java.io.Serializable;
import java.util.HashSet;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

import javax.servlet.http.HttpServletRequest;

import com.google.appengine.api.NamespaceManager;
import com.google.appengine.api.users.User;
import com.google.appengine.api.users.UserService;
import com.google.appengine.api.users.UserServiceFactory;
import com.google.apphosting.api.ApiProxy;

/**
 * Use this together with servlet filter {@link ServiceContextServletFilter}.
 * 
 * @author Patrik Nordwall
 */
public class AppEngineServiceContextFactory extends ServletContainerServiceContextFactory {

    public AppEngineServiceContextFactory() {
        super();
    }

    @Override
    protected ServiceContext createServiceContextImpl(HttpServletRequest request) {
        ServiceContext context = ServiceContextStore.get();
        if (context != null) {
            return context;
        }

        String sessionId = request.getRequestedSessionId();
        String appUrl = appUrl(request);
        context = createServiceContextFromAppengineEnvironment(sessionId, appUrl);

        return context;
    }

    protected ServiceContext createServiceContextFromAppengineEnvironment(String sessionId, String appUrl) {
        ServiceContext context;
        String applicationId = ApiProxy.getCurrentEnvironment().getAppId();
        String userId = userName();

        Set<String> roles = new HashSet<String>();
        if (ApiProxy.getCurrentEnvironment().isAdmin()) {
            roles.add("admin");
        }
        if (ApiProxy.getCurrentEnvironment().isLoggedIn()) {
            roles.add("loggedIn");
        }

        context = new ServiceContext(userId, sessionId, applicationId, roles);

        populateAttributesFromAppengineEnvironment(context);

        context.setProperty("appUrl", appUrl);

        return context;
    }

    protected String appUrl(HttpServletRequest request) {
        if (isRunningLocally(request)) {
            return "http://localhost:" + request.getLocalPort();
        } else {
            return System.getProperty("appUrl", "http://" + ApiProxy.getCurrentEnvironment().getAppId()
                    + ".appspot.com");
        }
    }

    private boolean isRunningLocally(HttpServletRequest request) {
        // TODO is there a better way?
        return (request.getLocalPort() > 1024);
    }

    protected void populateAttributesFromAppengineEnvironment(ServiceContext context) {
        context.setProperty("authDomain", ApiProxy.getCurrentEnvironment().getAuthDomain());
        context.setProperty("requestNamespace", NamespaceManager.getGoogleAppsNamespace());
        context.setProperty("versionId", ApiProxy.getCurrentEnvironment().getVersionId());
        context.setProperty("user.email", ApiProxy.getCurrentEnvironment().getEmail());
        User user = user();
        if (user != null) {
            context.setProperty("user.nickName", user.getNickname());
        }

        Map<String, Object> attributes = ApiProxy.getCurrentEnvironment().getAttributes();
        for (Entry<String, Object> each : attributes.entrySet()) {
            if (each.getValue() instanceof Serializable) {
                context.setProperty(each.getKey(), (Serializable) each.getValue());
            }
        }
    }

    private String userName() {
        User user = user();
        if (user == null) {
            return GUEST_USER;
        }
        return user.getNickname();
    }

    private User user() {
        UserService userService = UserServiceFactory.getUserService();
        User user = userService.getCurrentUser();
        return user;
    }

}