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package org.ufcspa.simdecs.bn.jpa;

import java.io.Serializable;
import javax.persistence.Query;
import javax.persistence.EntityNotFoundException;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Root;
import org.ufcspa.simdecs.bn.entity.Node;
import java.util.ArrayList;
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.transaction.UserTransaction;
import org.ufcspa.simdecs.bn.entity.BayesianNetwork;
import org.ufcspa.simdecs.bn.jpa.exceptions.NonexistentEntityException;
import org.ufcspa.simdecs.bn.jpa.exceptions.RollbackFailureException;

/**
 *
 * @author mchelem
 */
public class BayesianNetworkJpaController implements Serializable {

    public BayesianNetworkJpaController(UserTransaction utx, EntityManagerFactory emf) {
        this.utx = utx;
        this.emf = emf;
    }
    private UserTransaction utx = null;
    private EntityManagerFactory emf = null;

    public EntityManager getEntityManager() {
        return emf.createEntityManager();
    }

    public void create(BayesianNetwork bayesianNetwork) throws RollbackFailureException, Exception {
        if (bayesianNetwork.getNodes() == null) {
            bayesianNetwork.setNodes(new ArrayList<Node>());
        }
        EntityManager em = null;
        try {
            utx.begin();
            em = getEntityManager();
            List<Node> attachedNodes = new ArrayList<Node>();
            for (Node nodesNodeToAttach : bayesianNetwork.getNodes()) {
                nodesNodeToAttach = em.getReference(nodesNodeToAttach.getClass(), nodesNodeToAttach.getId());
                attachedNodes.add(nodesNodeToAttach);
            }
            bayesianNetwork.setNodes(attachedNodes);
            em.persist(bayesianNetwork);
            for (Node nodesNode : bayesianNetwork.getNodes()) {
                BayesianNetwork oldBayesianNetworkOfNodesNode = nodesNode.getBayesianNetwork();
                nodesNode.setBayesianNetwork(bayesianNetwork);
                nodesNode = em.merge(nodesNode);
                if (oldBayesianNetworkOfNodesNode != null) {
                    oldBayesianNetworkOfNodesNode.getNodes().remove(nodesNode);
                    oldBayesianNetworkOfNodesNode = em.merge(oldBayesianNetworkOfNodesNode);
                }
            }
            utx.commit();
        } catch (Exception ex) {
            try {
                utx.rollback();
            } catch (Exception re) {
                throw new RollbackFailureException("An error occurred attempting to roll back the transaction.", re);
            }
            throw ex;
        } finally {
            if (em != null) {
                em.close();
            }
        }
    }

    public void edit(BayesianNetwork bayesianNetwork) throws NonexistentEntityException, RollbackFailureException, Exception {
        EntityManager em = null;
        try {
            utx.begin();
            em = getEntityManager();
            BayesianNetwork persistentBayesianNetwork = em.find(BayesianNetwork.class, bayesianNetwork.getId());
            List<Node> nodesOld = persistentBayesianNetwork.getNodes();
            List<Node> nodesNew = bayesianNetwork.getNodes();
            List<Node> attachedNodesNew = new ArrayList<Node>();
            for (Node nodesNewNodeToAttach : nodesNew) {
                nodesNewNodeToAttach = em.getReference(nodesNewNodeToAttach.getClass(), nodesNewNodeToAttach.getId());
                attachedNodesNew.add(nodesNewNodeToAttach);
            }
            nodesNew = attachedNodesNew;
            bayesianNetwork.setNodes(nodesNew);
            bayesianNetwork = em.merge(bayesianNetwork);
            for (Node nodesOldNode : nodesOld) {
                if (!nodesNew.contains(nodesOldNode)) {
                    nodesOldNode.setBayesianNetwork(null);
                    nodesOldNode = em.merge(nodesOldNode);
                }
            }
            for (Node nodesNewNode : nodesNew) {
                if (!nodesOld.contains(nodesNewNode)) {
                    BayesianNetwork oldBayesianNetworkOfNodesNewNode = nodesNewNode.getBayesianNetwork();
                    nodesNewNode.setBayesianNetwork(bayesianNetwork);
                    nodesNewNode = em.merge(nodesNewNode);
                    if (oldBayesianNetworkOfNodesNewNode != null && !oldBayesianNetworkOfNodesNewNode.equals(bayesianNetwork)) {
                        oldBayesianNetworkOfNodesNewNode.getNodes().remove(nodesNewNode);
                        oldBayesianNetworkOfNodesNewNode = em.merge(oldBayesianNetworkOfNodesNewNode);
                    }
                }
            }
            utx.commit();
        } catch (Exception ex) {
            try {
                utx.rollback();
            } catch (Exception re) {
                throw new RollbackFailureException("An error occurred attempting to roll back the transaction.", re);
            }
            String msg = ex.getLocalizedMessage();
            if (msg == null || msg.length() == 0) {
                Long id = bayesianNetwork.getId();
                if (findBayesianNetwork(id) == null) {
                    throw new NonexistentEntityException("The bayesianNetwork with id " + id + " no longer exists.");
                }
            }
            throw ex;
        } finally {
            if (em != null) {
                em.close();
            }
        }
    }

    public void destroy(Long id) throws NonexistentEntityException, RollbackFailureException, Exception {
        EntityManager em = null;
        try {
            utx.begin();
            em = getEntityManager();
            BayesianNetwork bayesianNetwork;
            try {
                bayesianNetwork = em.getReference(BayesianNetwork.class, id);
                bayesianNetwork.getId();
            } catch (EntityNotFoundException enfe) {
                throw new NonexistentEntityException("The bayesianNetwork with id " + id + " no longer exists.", enfe);
            }
            List<Node> nodes = bayesianNetwork.getNodes();
            for (Node nodesNode : nodes) {
                nodesNode.setBayesianNetwork(null);
                nodesNode = em.merge(nodesNode);
            }
            em.remove(bayesianNetwork);
            utx.commit();
        } catch (Exception ex) {
            try {
                utx.rollback();
            } catch (Exception re) {
                throw new RollbackFailureException("An error occurred attempting to roll back the transaction.", re);
            }
            throw ex;
        } finally {
            if (em != null) {
                em.close();
            }
        }
    }

    public List<BayesianNetwork> findBayesianNetworkEntities() {
        return findBayesianNetworkEntities(true, -1, -1);
    }

    public List<BayesianNetwork> findBayesianNetworkEntities(int maxResults, int firstResult) {
        return findBayesianNetworkEntities(false, maxResults, firstResult);
    }

    private List<BayesianNetwork> findBayesianNetworkEntities(boolean all, int maxResults, int firstResult) {
        EntityManager em = getEntityManager();
        try {
            CriteriaQuery cq = em.getCriteriaBuilder().createQuery();
            cq.select(cq.from(BayesianNetwork.class));
            Query q = em.createQuery(cq);
            if (!all) {
                q.setMaxResults(maxResults);
                q.setFirstResult(firstResult);
            }
            return q.getResultList();
        } finally {
            em.close();
        }
    }

    public BayesianNetwork findBayesianNetwork(Long id) {
        EntityManager em = getEntityManager();
        try {
            return em.find(BayesianNetwork.class, id);
        } finally {
            em.close();
        }
    }

    public int getBayesianNetworkCount() {
        EntityManager em = getEntityManager();
        try {
            CriteriaQuery cq = em.getCriteriaBuilder().createQuery();
            Root<BayesianNetwork> rt = cq.from(BayesianNetwork.class);
            cq.select(em.getCriteriaBuilder().count(rt));
            Query q = em.createQuery(cq);
            return ((Long) q.getSingleResult()).intValue();
        } finally {
            em.close();
        }
    }
    
}