package net.thoughtforge.dao.jpa;

import java.lang.reflect.ParameterizedType;
import java.util.List;
import net.thoughtforge.dao.PersistentEntityDao;
import net.thoughtforge.model.PersistentEntity;
import org.springframework.orm.jpa.JpaTemplate;

public abstract class PersistentEntityDaoImpl implements PersistentEntityDao {

    private Class entityClass;
    private JpaTemplate jpaTemplate;

    @SuppressWarnings(value="unchecked")
    public PersistentEntityDaoImpl(JpaTemplate jpaTemplate) {
        this.jpaTemplate = jpaTemplate;
        ParameterizedType genericSuperclass = (ParameterizedType) getClass().getGenericSuperclass();
        this.entityClass = (Class) genericSuperclass.getActualTypeArguments()[0];
    }

    public final Entity findByIndexId(Integer indexId) {
        return (Entity) jpaTemplate.find(entityClass, indexId);
    }

    @SuppressWarnings("unchecked")
    public final List findByNamedQuery(String queryName) {
        return (List) jpaTemplate.findByNamedQuery(queryName);
    }

    @SuppressWarnings("unchecked")
    public final List findByNamedQueryAndParams(String queryName, Object ...params) {
        return (List) jpaTemplate.findByNamedQuery(queryName, params);
    }

    public final Entity findUniqueByNamedQuery(String queryName) {
        List results = findByNamedQuery(queryName);
        if (results.isEmpty()) {
            return null;
        } else {
            return results.get(0);
        }
    }

    public final Entity findUniqueByNamedQueryAndParams(String queryName, Object ...params) {
        List results = findByNamedQueryAndParams(queryName, params);
        if (results.isEmpty()) {
            return null;
        } else {
            return results.get(0);
        }
    }

    public final Entity merge(Entity persistentEntity) {
        return (Entity) jpaTemplate.merge(persistentEntity);
    }

    public final void refresh(Entity persistentEntity) {
        jpaTemplate.refresh(persistentEntity);
    }

    public final void remove(Entity persistentEntity) {
        jpaTemplate.remove(persistentEntity);
    }

    public final void save(Entity persistentEntity) {
        jpaTemplate.persist(persistentEntity);
    }
}