/*
    * 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.wa.starter.oidc;
  
  import java.nio.charset.StandardCharsets;
  import java.util.Optional;
  import javax.ws.rs.core.Response;
  import org.apache.syncope.common.lib.SyncopeClientException;
  import org.apache.syncope.common.lib.to.OIDCJWKSTO;
  import org.apache.syncope.common.lib.types.ClientExceptionType;
  import org.apache.syncope.common.rest.api.service.OIDCJWKSService;
  import org.apache.syncope.wa.bootstrap.WARestClient;
  import org.apereo.cas.oidc.jwks.generator.OidcJsonWebKeystoreGeneratorService;
  import org.jose4j.jwk.JsonWebKey;
  import org.jose4j.jwk.JsonWebKeySet;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.core.io.ByteArrayResource;
  import org.springframework.core.io.Resource;
  
  public class WAOIDCJWKSGeneratorService implements OidcJsonWebKeystoreGeneratorService {
  
      protected static final Logger LOG = LoggerFactory.getLogger(WAOIDCJWKSGeneratorService.class);
  
      protected final WARestClient waRestClient;
  
      protected final String jwksKeyId;
  
      protected final String jwksType;
  
      protected final int jwksKeySize;
  
      public WAOIDCJWKSGeneratorService(
              final WARestClient waRestClient,
              final String jwksKeyId,
              final String jwksType,
              final int jwksKeySize) {
  
          this.waRestClient = waRestClient;
          this.jwksKeyId = jwksKeyId;
          this.jwksType = jwksType;
          this.jwksKeySize = jwksKeySize;
      }
  
      @Override
      public JsonWebKeySet store(final JsonWebKeySet jsonWebKeySet) throws Exception {
          OIDCJWKSService service = waRestClient.getService(OIDCJWKSService.class);
          OIDCJWKSTO to = new OIDCJWKSTO();
          to.setJson(jsonWebKeySet.toJson(JsonWebKey.OutputControlLevel.INCLUDE_PRIVATE));
          service.set(to);
          return jsonWebKeySet;
      }
  
      @Override
      public Optional<Resource> find() {
          return Optional.of(generate());
      }
  
      @Override
      public Resource generate() {
          OIDCJWKSService service = waRestClient.getService(OIDCJWKSService.class);
          OIDCJWKSTO jwksTO = null;
          try {
              jwksTO = service.get();
          } catch (SyncopeClientException e) {
              if (e.getType() == ClientExceptionType.NotFound) {
                  try {
                      Response response = service.generate(jwksKeyId, jwksType, jwksKeySize);
                      jwksTO = response.readEntity(OIDCJWKSTO.class);
                  } catch (Exception ge) {
                      LOG.error("While generating new OIDC JWKS", ge);
                  }
              } else {
                  LOG.error("While reading OIDC JWKS", e);
              }
          }
          if (jwksTO == null) {
              throw new IllegalStateException("Unable to determine OIDC JWKS resource");
          }
          return new ByteArrayResource(jwksTO.getJson().getBytes(StandardCharsets.UTF_8), "OIDC JWKS");
      }
  }