/*
    * 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.logic;
  
  import java.lang.reflect.Method;
  import java.time.OffsetDateTime;
  import java.util.Collections;
  import java.util.List;
  import java.util.stream.Collectors;
  import org.apache.commons.lang3.tuple.Pair;
  import org.apache.syncope.common.lib.SyncopeClientException;
  import org.apache.syncope.common.lib.to.AccessTokenTO;
  import org.apache.syncope.common.lib.types.CipherAlgorithm;
  import org.apache.syncope.common.lib.types.ClientExceptionType;
  import org.apache.syncope.common.lib.types.IdRepoEntitlement;
  import org.apache.syncope.core.persistence.api.dao.AccessTokenDAO;
  import org.apache.syncope.core.persistence.api.dao.NotFoundException;
  import org.apache.syncope.core.persistence.api.dao.search.OrderByClause;
  import org.apache.syncope.core.persistence.api.entity.AccessToken;
  import org.apache.syncope.core.provisioning.api.data.AccessTokenDataBinder;
  import org.apache.syncope.core.provisioning.api.serialization.POJOHelper;
  import org.apache.syncope.core.spring.security.AuthContextUtils;
  import org.apache.syncope.core.spring.security.Encryptor;
  import org.apache.syncope.core.spring.security.SecurityProperties;
  import org.springframework.security.access.prepost.PreAuthorize;
  
  public class AccessTokenLogic extends AbstractTransactionalLogic<AccessTokenTO> {
  
      protected static final Encryptor ENCRYPTOR = Encryptor.getInstance();
  
      protected static byte[] getAuthorities() {
          byte[] authorities = null;
          try {
              authorities = ENCRYPTOR.encode(POJOHelper.serialize(
                      AuthContextUtils.getAuthorities()), CipherAlgorithm.AES).
                      getBytes();
          } catch (Exception e) {
              LOG.error("Could not fetch authorities", e);
          }
  
          return authorities;
      }
  
      protected final SecurityProperties securityProperties;
  
      protected final AccessTokenDataBinder binder;
  
      protected final AccessTokenDAO accessTokenDAO;
  
      public AccessTokenLogic(
              final SecurityProperties securityProperties,
              final AccessTokenDataBinder binder,
              final AccessTokenDAO accessTokenDAO) {
  
          this.securityProperties = securityProperties;
          this.binder = binder;
          this.accessTokenDAO = accessTokenDAO;
      }
  
      @PreAuthorize("isAuthenticated()")
      public Pair<String, OffsetDateTime> login() {
          if (securityProperties.getAnonymousUser().equals(AuthContextUtils.getUsername())) {
              SyncopeClientException sce = SyncopeClientException.build(ClientExceptionType.InvalidRequest);
              sce.getElements().add(securityProperties.getAnonymousUser() + " cannot be granted an access token");
              throw sce;
          }
  
          return binder.create(
                  AuthContextUtils.getUsername(),
                  Collections.<String, Object>emptyMap(),
                  getAuthorities(),
                  false);
      }
  
      @PreAuthorize("isAuthenticated()")
      public Pair<String, OffsetDateTime> refresh() {
          AccessToken accessToken = accessTokenDAO.findByOwner(AuthContextUtils.getUsername());
          if (accessToken == null) {
              throw new NotFoundException("AccessToken for " + AuthContextUtils.getUsername());
          }
  
          return binder.update(accessToken, getAuthorities());
      }
 
     @PreAuthorize("isAuthenticated()")
     public void logout() {
         AccessToken accessToken = accessTokenDAO.findByOwner(AuthContextUtils.getUsername());
         if (accessToken == null) {
             throw new NotFoundException("AccessToken for " + AuthContextUtils.getUsername());
         }
 
         delete(accessToken.getKey());
     }
 
     @PreAuthorize("hasRole('" + IdRepoEntitlement.ACCESS_TOKEN_LIST + "')")
     public Pair<Integer, List<AccessTokenTO>> list(
             final int page,
             final int size,
             final List<OrderByClause> orderByClauses) {
 
         Integer count = accessTokenDAO.count();
 
         List<AccessTokenTO> result = accessTokenDAO.findAll(page, size, orderByClauses).stream().
                 map(binder::getAccessTokenTO).collect(Collectors.toList());
 
         return Pair.of(count, result);
     }
 
     @PreAuthorize("hasRole('" + IdRepoEntitlement.ACCESS_TOKEN_DELETE + "')")
     public void delete(final String key) {
         accessTokenDAO.delete(key);
     }
 
     @Override
     protected AccessTokenTO resolveReference(final Method method, final Object... args)
             throws UnresolvedReferenceException {
 
         throw new UnresolvedReferenceException();
     }
 }