#pragma once

#include <chrono>

#include <memory>

#include <string>

#include "envoy/http/async_client.h"

#include "envoy/http/message.h"

namespace Envoy {

namespace Router {

/**

 * Interface used to shadow complete requests to an alternate upstream cluster in a "fire and

 * forget" fashion. Right now this interface takes a fully buffered request and cannot be used for

 * streaming. This is sufficient for current use cases.

 */

class ShadowWriter {

public:

  /**

   * Shadow a request.

   * @param cluster supplies the cluster name to shadow to.

   * @param message supplies the complete request to shadow.

   * @param options supplies the request options for the underlying asynchronous request.

   */

  virtual void shadow(const std::string& cluster, Http::RequestMessagePtr&& request,

                      const Http::AsyncClient::RequestOptions& options) PURE;

  /**

   * Initialize shadowing a request. Differs from the above in that additional

   * data can be passed to the returned handle after the headers have been sent.

   * @param cluster supplies the cluster name to shadow to.

   * @param headers supplies the headers for initializing the shadow.

   * @param options supplies the request options for the underlying asynchronous request.

   * @return OngoingRequest* pointer owned by the AsyncClient which can have additional data and

   *                         trailers sent to it. Can be null if the stream is immediately

   *                         cancelled.

   */

  virtual Http::AsyncClient::OngoingRequest*

  streamingShadow(const std::string& cluster, Http::RequestHeaderMapPtr&& headers,

                  const Http::AsyncClient::RequestOptions& options) PURE;

};

using ShadowWriterPtr = std::unique_ptr<ShadowWriter>;

} // namespace Router

} // namespace Envoy