/*
    * Copyright 2022 the original author or authors.
    *
    * Licensed 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.bremersee.apiclient.webflux.contract.spring;
  
  import java.lang.reflect.Method;
  import java.util.Optional;
  import org.bremersee.apiclient.webflux.InvocationParameter;
  import org.reactivestreams.Publisher;
  import org.springframework.core.ResolvableType;
  import org.springframework.core.io.buffer.DataBuffer;
  import org.springframework.web.reactive.function.BodyInserters;
  import org.springframework.web.reactive.function.client.WebClient.RequestBodyUriSpec;
  import org.springframework.web.reactive.function.client.WebClient.RequestHeadersUriSpec;
  
  /**
   * The data buffers inserter.
   *
   * @author Christian Bremer
   */
  public class DataBuffersInserter extends SingleBodyInserter<Publisher<DataBuffer>> {
  
    @Override
    protected boolean isPossibleBodyValue(InvocationParameter invocationParameter) {
      return invocationParameter.getValue() instanceof Publisher
          && isDataBuffer(invocationParameter);
    }
  
    private boolean isDataBuffer(InvocationParameter invocationParameter) {
      Method method = invocationParameter.getMethod();
      int index = invocationParameter.getIndex();
      return Optional.of(ResolvableType.forMethodParameter(method, index))
          .filter(ResolvableType::hasGenerics)
          .map(resolvableType -> resolvableType.resolveGeneric(0))
          .filter(DataBuffer.class::isAssignableFrom)
          .isPresent();
    }
  
    @Override
    protected Publisher<DataBuffer> mapBody(InvocationParameter invocationParameter) {
      //noinspection unchecked
      return (Publisher<DataBuffer>) invocationParameter.getValue();
    }
  
    @Override
    protected RequestHeadersUriSpec<?> insert(
        Publisher<DataBuffer> body,
        RequestBodyUriSpec requestBodyUriSpec) {
  
      //noinspection rawtypes
      return (RequestHeadersUriSpec) requestBodyUriSpec.body(BodyInserters.fromDataBuffers(body));
    }
  
  }