tech.aroma.service.operations.FollowApplicationOperation Maven / Gradle / Ivy

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/*
 * Copyright 2016 RedRoma, Inc.
 *
 * 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 tech.aroma.service.operations;


import javax.inject.Inject;
import org.apache.thrift.TException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import tech.aroma.data.ActivityRepository;
import tech.aroma.data.ApplicationRepository;
import tech.aroma.data.FollowerRepository;
import tech.aroma.data.UserRepository;
import tech.aroma.thrift.Application;
import tech.aroma.thrift.User;
import tech.aroma.thrift.events.ApplicationFollowed;
import tech.aroma.thrift.events.Event;
import tech.aroma.thrift.events.EventType;
import tech.aroma.thrift.exceptions.InvalidArgumentException;
import tech.aroma.thrift.service.FollowApplicationRequest;
import tech.aroma.thrift.service.FollowApplicationResponse;
import tech.sirwellington.alchemy.arguments.AlchemyAssertion;
import tech.sirwellington.alchemy.thrift.operations.ThriftOperation;

import static java.time.Instant.now;
import static tech.sirwellington.alchemy.arguments.Arguments.checkThat;
import static tech.sirwellington.alchemy.arguments.assertions.Assertions.notNull;
import static tech.sirwellington.alchemy.arguments.assertions.StringAssertions.nonEmptyString;
import static tech.sirwellington.alchemy.arguments.assertions.StringAssertions.validUUID;
import static tech.sirwellington.alchemy.generator.AlchemyGenerator.one;
import static tech.sirwellington.alchemy.generator.StringGenerators.uuids;

/**
 *
 * @author SirWellington
 */
final class FollowApplicationOperation implements ThriftOperation
{
    private final static Logger LOG = LoggerFactory.getLogger(FollowApplicationOperation.class);
    
    private final ActivityRepository activityRepo;
    private final ApplicationRepository appRepo;
    private final FollowerRepository followRepo;
    private final UserRepository userRepo;

    @Inject
    FollowApplicationOperation(ActivityRepository activityRepo,
                               ApplicationRepository appRepo, 
                               FollowerRepository followRepo, 
                               UserRepository userRepo)
    {
        checkThat(activityRepo, appRepo, followRepo, userRepo)
            .are(notNull());
        
        this.activityRepo = activityRepo;
        this.appRepo = appRepo;
        this.followRepo = followRepo;
        this.userRepo = userRepo;
    }
    
    @Override
    public FollowApplicationResponse process(FollowApplicationRequest request) throws TException
    {
        checkThat(request)
            .throwing(ex -> new InvalidArgumentException(ex.getMessage()))
            .is(good());
        
        String appId = request.applicationId;
        Application app = appRepo.getById(appId);
        
        String userId = request.token.userId;
        User user = userRepo.getUser(userId);
        
        followRepo.saveFollowing(user, app);
        notifyOwnersOfNewFollower(user, app);
        LOG.debug("Following of App {} by User {} successfully saved", app, user);
        
        return new FollowApplicationResponse();
    }

    private AlchemyAssertion good()
    {
        return request ->
        {
            checkThat(request).is(notNull());
            
            checkThat(request.applicationId)
                .usingMessage("missing applicationId")
                .is(nonEmptyString())
                .usingMessage("applicationId must be a UUID")
                .is(validUUID());
            
            checkThat(request.token)
                .usingMessage("request missing token")
                .is(notNull());
            
            checkThat(request.token.userId)
                .usingMessage("User Token missing userId")
                .is(nonEmptyString())
                .usingMessage("userId in token must be a UUID")
                .is(validUUID());
        };
    }

    private void notifyOwnersOfNewFollower(User follower, Application app)
    {
        Event event = createEventToNotifyOwners(follower, app);

        app.owners.stream()
            .map(id -> new User().setUserId(id))
            .forEach(owner -> this.tryToNotify(owner, event));
    }

    private Event createEventToNotifyOwners(User follower, Application app)
    {
        EventType eventType = createEventTypeFor(follower, app);

        return new Event()
            .setApplication(app)
            .setApplicationId(app.applicationId)
            .setActor(follower)
            .setUserIdOfActor(follower.userId)
            .setTimestamp(now().toEpochMilli())
            .setEventId(one(uuids))
            .setEventType(eventType);
    }

    private void tryToNotify(User user, Event event)
    {
        try
        {
            activityRepo.saveEvent(event, user);
        }
        catch (Exception ex)
        {
            LOG.error("Failed to notify User [{}] of Event [{}]", user, event, ex);
        }
    }

    private EventType createEventTypeFor(User follower, Application app)
    {
        ApplicationFollowed appFollowed = new ApplicationFollowed()
            .setMessage(follower.firstName + " has followed " + app.name);

        EventType eventType = new EventType();
        eventType.setApplicationFollowed(appFollowed);
        return eventType;
    }

}