/**
 * Licensed to Apereo under one or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information regarding copyright ownership. Apereo
 * 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 the
 * following location:
 *
 * <p>http://www.apache.org/licenses/LICENSE-2.0
 *
 * <p>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.apereo.portal.permission.dao.jpa;

import com.google.common.base.Function;
import java.util.ArrayList;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;
import javax.persistence.TypedQuery;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.JoinType;
import javax.persistence.criteria.Root;
import org.apereo.portal.jpa.BasePortalJpaDao;
import org.apereo.portal.jpa.OpenEntityManager;
import org.apereo.portal.permission.IPermissionActivity;
import org.apereo.portal.permission.IPermissionOwner;
import org.apereo.portal.permission.dao.IPermissionOwnerDao;
import org.springframework.stereotype.Repository;

/**
 * JpaPermissionOwnerDao provides a default JPA/Hibernate implementation of the IPermissionOwnerDao
 * interface.
 *
 * @since 3.3
 */
@Repository("permissionOwnerDao")
public class JpaPermissionOwnerDao extends BasePortalJpaDao implements IPermissionOwnerDao {

    private CriteriaQuery<PermissionOwnerImpl> findAllPermissionOwners;

    @Override
    public void afterPropertiesSet() throws Exception {
        this.findAllPermissionOwners =
                this.createCriteriaQuery(
                        new Function<CriteriaBuilder, CriteriaQuery<PermissionOwnerImpl>>() {
                            @Override
                            public CriteriaQuery<PermissionOwnerImpl> apply(CriteriaBuilder cb) {
                                final CriteriaQuery<PermissionOwnerImpl> criteriaQuery =
                                        cb.createQuery(PermissionOwnerImpl.class);
                                final Root<PermissionOwnerImpl> ownerRoot =
                                        criteriaQuery.from(PermissionOwnerImpl.class);
                                criteriaQuery.select(ownerRoot);
                                ownerRoot.fetch(PermissionOwnerImpl_.activities, JoinType.LEFT);

                                return criteriaQuery;
                            }
                        });
    }

    @Override
    public List<IPermissionOwner> getAllPermissionOwners() {
        final TypedQuery<PermissionOwnerImpl> query =
                this.createCachedQuery(this.findAllPermissionOwners);

        final List<PermissionOwnerImpl> resultList = query.getResultList();
        return new ArrayList<IPermissionOwner>(new LinkedHashSet<IPermissionOwner>(resultList));
    }

    @Override
    @PortalTransactional
    public IPermissionOwner getOrCreatePermissionOwner(String name, String fname) {
        IPermissionOwner owner = getPermissionOwner(fname);
        if (owner == null) {
            owner = new PermissionOwnerImpl(name, fname);
            this.getEntityManager().persist(owner);
        }
        return owner;
    }

    @Override
    public IPermissionOwner getPermissionOwner(long id) {
        return getEntityManager().find(PermissionOwnerImpl.class, id);
    }

    @OpenEntityManager(unitName = PERSISTENCE_UNIT_NAME)
    @Override
    public IPermissionOwner getPermissionOwner(String fname) {
        final NaturalIdQuery<PermissionOwnerImpl> query =
                this.createNaturalIdQuery(PermissionOwnerImpl.class);
        query.using(PermissionOwnerImpl_.fname, fname);
        return query.load();
    }

    @Override
    @PortalTransactional
    public IPermissionOwner saveOwner(IPermissionOwner owner) {
        this.getEntityManager().persist(owner);
        return owner;
    }

    @Override
    @PortalTransactional
    public IPermissionActivity getOrCreatePermissionActivity(
            IPermissionOwner owner, String name, String fname, String targetProviderKey) {
        IPermissionActivity activity = getPermissionActivity(owner.getId(), fname);
        if (activity == null) {
            activity = new PermissionActivityImpl(name, fname, targetProviderKey);
            owner.getActivities().add(activity);
        }
        return activity;
    }

    @Override
    public IPermissionActivity getPermissionActivity(long id) {
        return getEntityManager().find(PermissionActivityImpl.class, id);
    }

    @Override
    public IPermissionActivity getPermissionActivity(long ownerId, String activityFname) {
        final IPermissionOwner permissionOwner = this.getPermissionOwner(ownerId);
        return findActivity(permissionOwner, activityFname);
    }

    @PortalTransactionalReadOnly
    @Override
    public IPermissionActivity getPermissionActivity(String ownerFname, String activityFname) {
        final IPermissionOwner permissionOwner = this.getPermissionOwner(ownerFname);
        return findActivity(permissionOwner, activityFname);
    }

    @Override
    @PortalTransactional
    public IPermissionActivity savePermissionActivity(IPermissionActivity activity) {
        this.getEntityManager().persist(activity);
        return activity;
    }

    protected IPermissionActivity findActivity(
            final IPermissionOwner permissionOwner, String activityFname) {
        if (permissionOwner == null) {
            return null;
        }

        final Set<IPermissionActivity> activities = permissionOwner.getActivities();
        for (final IPermissionActivity permissionActivity : activities) {
            if (activityFname.equals(permissionActivity.getFname())) {
                return permissionActivity;
            }
        }

        return null;
    }
}