/**
* 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 jug.dao;
import java.util.Collection;
import javax.ejb.Lock;
import javax.ejb.LockType;
import javax.ejb.Singleton;
import javax.inject.Inject;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import jug.domain.Subject;
import jug.domain.Value;
import jug.domain.Vote;
@Singleton
@Lock(LockType.READ)
public class SubjectDao {
@PersistenceContext(unitName = "polling")
private EntityManager em;
@Inject
private ReadSubjectDao readDao;
public Subject create(final String name, final String question) {
final Subject subject = new Subject();
subject.setName(name);
subject.setQuestion(question);
em.persist(subject);
return subject;
}
public Subject addVote(final Subject subject, final Vote vote) {
final Vote foundVote = retrieve(vote, Vote.class, vote.getId());
final Subject subjectToUpdate = retrieve(subject, Subject.class, subject.getId());
subjectToUpdate.getVotes().add(foundVote);
return subjectToUpdate;
}
public Subject findByName(final String name) {
return readDao.findByName(name);
}
public Collection<Subject> findAll() {
return readDao.findAll();
}
public int subjectLikeVoteNumber(final String subjectName) {
return subjectVoteNumber(subjectName, Value.I_LIKE);
}
public int subjectNotLikeVoteNumber(final String subjectName) {
return subjectVoteNumber(subjectName, Value.I_DONT_LIKE);
}
private int subjectVoteNumber(final String subjectName, final Value value) {
return em.createNamedQuery(Subject.COUNT_VOTE, Number.class)
.setParameter("name", subjectName)
.setParameter("value", value)
.getSingleResult().intValue();
}
private <T> T retrieve(final T object, final Class<T> clazz, long id) {
if (em.contains(object)) {
return object;
}
final T t = em.find(clazz, id);
if (t == null) {
throw new IllegalArgumentException(clazz.getSimpleName() + " not found");
}
return t;
}
public Subject bestSubject() {
int bestScore = 0;
Subject best = null;
for (Subject subject : findAll()) {
int currentScore = subject.score();
if (best == null || bestScore < currentScore) {
bestScore = currentScore;
best = subject;
}
}
return best;
}
@Singleton
@Lock(LockType.READ)
@PersistenceContext(name = "polling")
public static interface ReadSubjectDao {
Subject findByName(final String name);
Collection<Subject> findAll();
}
}