package jsfdb.model.dao;

import jsfdb.model.LoginInfo;
import jsfdb.model.Subscriber;
import jsfdb.model.ModelUtils;
import jsfdb.model.err.IncorrectPasswordException;
import jsfdb.model.err.LoginException;
import jsfdb.model.err.ProfileException;
import jsfdb.model.err.SubscribeException;
import jsfdb.model.err.UnknownSubscriberException;
import jsfdb.model.err.UnsubscribeException;

import oracle.toplink.expressions.ExpressionBuilder;
import oracle.toplink.queryframework.ReadObjectQuery;
import oracle.toplink.sessions.Session;
import oracle.toplink.sessions.UnitOfWork;
import oracle.toplink.threetier.ClientSession;
import oracle.toplink.threetier.Server;
import oracle.toplink.tools.sessionmanagement.SessionManager;

public class TopLinkSubscriberDAO implements SubscriberDAO {
    private Server serverSession;

    public TopLinkSubscriberDAO() {
        SessionManager manager = SessionManager.getManager();
        String id = ModelUtils.getResource("TopLinkSession");
        ClassLoader loader = this.getClass().getClassLoader();
        serverSession = (Server) manager.getSession(id, loader);
        Runtime.getRuntime().addShutdownHook(new Thread() {
            public void run() {
                serverSession.logout();
                SessionManager.getManager().getSessions().remove(
                    ModelUtils.getResource("TopLinkSession"));
            }
        });
    }

    private ClientSession acquireClientSession() {
        return serverSession.acquireClientSession();
    }

    private UnitOfWork acquireUnitOfWork() {
        return acquireClientSession().acquireUnitOfWork();
    }

    private Subscriber read(Session session, String email) {
        ReadObjectQuery query
            = new ReadObjectQuery(Subscriber.class);
        ExpressionBuilder builder = new ExpressionBuilder();
        query.setSelectionCriteria(
            builder.get("email").equal(email));
        return (Subscriber) session.executeQuery(query);
    }

    public Subscriber select(LoginInfo loginInfo)
            throws LoginException,
            UnknownSubscriberException,
            IncorrectPasswordException {
        Subscriber s = null;
        try {
            ClientSession session = acquireClientSession();
            s = read(session, loginInfo.getEmail());
        } catch (Exception x) {
            ModelUtils.log(x);
            throw new LoginException();
        }
        if (s == null)
            throw new UnknownSubscriberException();
        if (!s.getPassword().equals(loginInfo.getPassword()))
            throw new IncorrectPasswordException();
        return s;
    }

    public void insert(Subscriber subscriber)
            throws SubscribeException {
        try {
            UnitOfWork uow = acquireUnitOfWork();
            Subscriber s = new Subscriber();
            ModelUtils.copy(subscriber, s);
            uow.registerObject(s);
            uow.commit();
        } catch (Exception x) {
            ModelUtils.log(x);
            throw new SubscribeException();
        }
    }

    public void update(Subscriber subscriber)
            throws ProfileException {
        try {
            UnitOfWork uow = acquireUnitOfWork();
            Subscriber s = read(uow, subscriber.getEmail());
            ModelUtils.copy(subscriber, s);
            uow.commit();
        } catch (Exception x) {
            ModelUtils.log(x);
            throw new ProfileException();
        }
    }

    public void delete(Subscriber subscriber)
            throws UnsubscribeException {
        try {
            UnitOfWork uow = acquireUnitOfWork();
            Subscriber s = read(uow, subscriber.getEmail());
            uow.deleteObject(s);
            uow.commit();
        } catch (Exception x) {
            ModelUtils.log(x);
            throw new UnsubscribeException();
        }
    }

}