/*
    * 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 org.apache.syncope.core.persistence.jpa.dao;
  
  import java.time.OffsetDateTime;
  import java.util.List;
  import javax.persistence.NoResultException;
  import javax.persistence.Query;
  import javax.persistence.TypedQuery;
  import org.apache.commons.lang3.StringUtils;
  import org.apache.syncope.core.persistence.api.dao.AccessTokenDAO;
  import org.apache.syncope.core.persistence.api.dao.search.OrderByClause;
  import org.apache.syncope.core.persistence.api.entity.AccessToken;
  import org.apache.syncope.core.persistence.jpa.entity.JPAAccessToken;
  import org.springframework.transaction.annotation.Transactional;
  import org.springframework.util.ReflectionUtils;
  
  public class JPAAccessTokenDAO extends AbstractDAO<AccessToken> implements AccessTokenDAO {
  
      @Transactional(readOnly = true)
      @Override
      public AccessToken find(final String key) {
          return entityManager().find(JPAAccessToken.class, key);
      }
  
      @Transactional(readOnly = true)
      @Override
      public AccessToken findByOwner(final String username) {
          TypedQuery<AccessToken> query = entityManager().createQuery(
                  "SELECT e FROM " + JPAAccessToken.class.getSimpleName() + " e "
                  + "WHERE e.owner=:username", AccessToken.class);
          query.setParameter("username", username);
  
          AccessToken result = null;
          try {
              result = query.getSingleResult();
          } catch (NoResultException e) {
              LOG.debug("No token for user {} could be found", username, e);
          }
  
          return result;
      }
  
      private static StringBuilder buildFindAllQuery() {
          return new StringBuilder("SELECT e FROM ").
                  append(JPAAccessToken.class.getSimpleName()).
                  append(" e WHERE 1=1");
      }
  
      @Transactional(readOnly = true)
      @Override
      public int count() {
          StringBuilder queryString = buildFindAllQuery();
  
          Query query = entityManager().createQuery(StringUtils.replaceOnce(
                  queryString.toString(), "SELECT e", "SELECT COUNT(e)"));
          return ((Number) query.getSingleResult()).intValue();
      }
  
      private static String toOrderByStatement(final List<OrderByClause> orderByClauses) {
          StringBuilder statement = new StringBuilder();
  
          orderByClauses.forEach(clause -> {
              String field = clause.getField().trim();
              if (ReflectionUtils.findField(JPAAccessToken.class, field) != null) {
                  statement.append("e.").append(field).append(' ').append(clause.getDirection().name());
              }
          });
  
          if (statement.length() == 0) {
              statement.append(" ORDER BY e.expirationTime DESC");
          } else {
              statement.insert(0, "ORDER BY ");
          }
          return statement.toString();
      }
  
      @Transactional(readOnly = true)
      @Override
      public List<AccessToken> findAll(final int page, final int itemsPerPage, final List<OrderByClause> orderByClauses) {
          StringBuilder queryString = buildFindAllQuery().append(toOrderByStatement(orderByClauses));
  
          TypedQuery<AccessToken> query = entityManager().createQuery(queryString.toString(), AccessToken.class);
 
         query.setFirstResult(itemsPerPage * (page <= 0 ? 0 : page - 1));
 
         if (itemsPerPage > 0) {
             query.setMaxResults(itemsPerPage);
         }
 
         return query.getResultList();
     }
 
     @Transactional(rollbackFor = Throwable.class)
     @Override
     public AccessToken save(final AccessToken accessToken) {
         return entityManager().merge(accessToken);
     }
 
     @Transactional(rollbackFor = Throwable.class)
     @Override
     public void delete(final String key) {
         AccessToken accessToken = find(key);
         if (accessToken == null) {
             return;
         }
 
         delete(accessToken);
     }
 
     @Override
     public void delete(final AccessToken accessToken) {
         entityManager().remove(accessToken);
     }
 
     @Override
     public int deleteExpired() {
         Query query = entityManager().createQuery(
                 "DELETE FROM " + JPAAccessToken.class.getSimpleName() + " e "
                 + "WHERE e.expirationTime < :now");
         query.setParameter("now", OffsetDateTime.now());
         return query.executeUpdate();
     }
 }