// GNU Lesser General Public License v3.0
// Copyright (c) 2025 Bart Beumer <bart@4beumer.nl>
//
// This program is free software; you can redistribute it and/or modify it
// under the terms of the GNU Lesser General Public License v3.0 as published by
// the Free Software Foundation.
//
#pragma once
#include <boost/asio/io_context.hpp>
#include <boost/asio/ip/tcp.hpp>
#include <boost/beast.hpp>
#include <functional>
#include <utility>

namespace bmrshared::web
{

class response_promise final
{
private:
  class response_writer_interface
  {
  public:
    virtual ~response_writer_interface() = default;
    virtual void write_response(boost::beast::tcp_stream&) = 0;
  };

  template<typename TResponse>
  class response_writer : public response_writer_interface
  {
  public:
    template<typename... TArgs>
    response_writer(TArgs... args)
      : m_response(args...)
    {}

    ~response_writer() override = default;

    void write_response(boost::beast::tcp_stream& stream) override
    {
      boost::beast::http::write(stream, m_response);
    }

    TResponse& response()
    {
      return m_response;
    }

  private:
    TResponse m_response;
  };


  public:
    using response_sender = std::function<void(boost::beast::tcp_stream& stream)>;
    using callback_on_response = std::function<void(response_sender fnSendResponse)>;

    response_promise() = delete;
    explicit response_promise(callback_on_response cbOnResponse);
    ~response_promise();

    template<typename TResponse, typename... TArgs>
    TResponse& CreateResponse(TArgs&&... args)
    {
      auto created = std::make_unique<response_writer<TResponse>>(std::forward<TArgs>(args)...);
      auto& resp = created->response();
      m_response_writer = std::move(created);
      return resp;
    }

  private:
    callback_on_response m_call_on_response;
    std::shared_ptr<response_writer_interface> m_response_writer;
};
} // namespace bmrshared::web