/*
    * 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.client.lib;
  
  import jakarta.ws.rs.BadRequestException;
  import jakarta.ws.rs.ForbiddenException;
  import jakarta.ws.rs.NotAuthorizedException;
  import jakarta.ws.rs.NotFoundException;
  import jakarta.ws.rs.WebApplicationException;
  import jakarta.ws.rs.core.GenericType;
  import jakarta.ws.rs.core.Response;
  import jakarta.ws.rs.ext.Provider;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Set;
  import org.apache.commons.lang3.StringUtils;
  import org.apache.cxf.jaxrs.client.ResponseExceptionMapper;
  import org.apache.syncope.common.lib.SyncopeClientCompositeException;
  import org.apache.syncope.common.lib.SyncopeClientException;
  import org.apache.syncope.common.lib.to.ErrorTO;
  import org.apache.syncope.common.lib.types.ClientExceptionType;
  import org.apache.syncope.common.rest.api.RESTHeaders;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  @Provider
  public class RestClientExceptionMapper implements ResponseExceptionMapper<Exception> {
  
      private static final Logger LOG = LoggerFactory.getLogger(RestClientExceptionMapper.class);
  
      @Override
      public Exception fromResponse(final Response response) {
          int statusCode = response.getStatus();
          String message = response.getHeaderString(RESTHeaders.ERROR_INFO);
  
          Exception ex;
          SyncopeClientCompositeException scce = checkSyncopeClientCompositeException(response);
          if (scce != null) {
              // 1. Check for client (possibly composite) exception in HTTP header
              ex = scce.getExceptions().size() == 1
                      ? scce.getExceptions().iterator().next()
                      : scce;
          } else if (statusCode == Response.Status.UNAUTHORIZED.getStatusCode()) {
              // 2. Map SC_UNAUTHORIZED
              ex = new NotAuthorizedException(StringUtils.isBlank(message)
                      ? "Remote unauthorized exception"
                      : message,
                      response);
          } else if (statusCode == Response.Status.FORBIDDEN.getStatusCode()) {
              // 3. Map SC_FORBIDDEN
              ex = new ForbiddenException(StringUtils.isBlank(message)
                      ? "Remote forbidden exception"
                      : message,
                      response);
          } else if (statusCode == Response.Status.BAD_REQUEST.getStatusCode()) {
              // 4. Map SC_BAD_REQUEST
              ex = StringUtils.isBlank(message)
                      ? new BadRequestException(response)
                      : new BadRequestException(message, response);
          } else {
              // 5. All other codes are mapped to runtime exception with HTTP code information
              ex = new WebApplicationException("Remote exception with status code: %s".
                      formatted(Response.Status.fromStatusCode(statusCode).name()),
                      response);
          }
  
          if (ex instanceof NotFoundException
                  || (ex instanceof SyncopeClientException sce && sce.getType() == ClientExceptionType.NotFound)) {
  
              if (LOG.isDebugEnabled()) {
                  LOG.debug("Exception thrown", ex);
              } else {
                  LOG.warn("{} thrown: {}", NotFoundException.class.getSimpleName(), ex.getMessage());
              }
          } else {
              LOG.error("Exception thrown", ex);
          }
  
          return ex;
      }
  
      private static SyncopeClientCompositeException checkSyncopeClientCompositeException(final Response response) {
          SyncopeClientCompositeException compException = SyncopeClientException.buildComposite();
 
         // Attempts to read ErrorTO or List<ErrorTO> as entity...
         List<ErrorTO> errors = null;
         try {
             ErrorTO error = response.readEntity(ErrorTO.class);
             if (error != null) {
                 errors = List.of(error);
             }
         } catch (Exception e) {
             LOG.debug("Could not read {}, attempting to read composite...", ErrorTO.class.getName(), e);
         }
         if (errors == null) {
             try {
                 errors = response.readEntity(new GenericType<>() {
                 });
             } catch (Exception e) {
                 LOG.debug("Could not read {} list, attempting to read headers...", ErrorTO.class.getName(), e);
             }
         }
 
         // ...if not possible, attempts to parse response headers
         if (errors == null) {
             List<String> exTypesInHeaders = response.getStringHeaders().get(RESTHeaders.ERROR_CODE);
             if (exTypesInHeaders == null) {
                 LOG.debug("No " + RESTHeaders.ERROR_CODE + " provided");
                 return null;
             }
             List<String> exInfos = response.getStringHeaders().get(RESTHeaders.ERROR_INFO);
 
             Set<String> handledExceptions = new HashSet<>();
             exTypesInHeaders.forEach(exTypeAsString -> {
                 ClientExceptionType exceptionType = null;
                 try {
                     exceptionType = ClientExceptionType.fromHeaderValue(exTypeAsString);
                 } catch (IllegalArgumentException e) {
                     LOG.error("Unexpected value of " + RESTHeaders.ERROR_CODE + ": {}", exTypeAsString, e);
                 }
                 if (exceptionType != null) {
                     handledExceptions.add(exTypeAsString);
 
                     SyncopeClientException clientException = SyncopeClientException.build(exceptionType);
                     if (exInfos != null && !exInfos.isEmpty()) {
                         for (String element : exInfos) {
                             if (element.startsWith(exceptionType.name())) {
                                 clientException.getElements().add(StringUtils.substringAfter(element, ":"));
                             }
                         }
                     }
                     compException.addException(clientException);
                 }
             });
 
             exTypesInHeaders.removeAll(handledExceptions);
             if (!exTypesInHeaders.isEmpty()) {
                 LOG.error("Unmanaged exceptions: {}", exTypesInHeaders);
             }
         } else {
             for (ErrorTO error : errors) {
                 SyncopeClientException clientException = SyncopeClientException.build(error.getType());
                 clientException.getElements().addAll(error.getElements());
                 compException.addException(clientException);
             }
         }
 
         if (compException.hasExceptions()) {
             return compException;
         }
 
         return null;
     }
 }