module;

#include <boost/beast/core.hpp>
#include <boost/beast/http.hpp>

export module routemon:http.common;

namespace beast = boost::beast;
export namespace bhttp = beast::http;

namespace boost::beast {

namespace concepts {

template <class T>
concept buffers_generator = beast::is_buffers_generator<T>::value;

template <class T>
concept const_buffer_sequence = beast::is_const_buffer_sequence<T>::value;

} // namespace concepts

namespace http::concepts {

template <class T>
concept fields = is_fields<T>::value;

template <class T>
concept body = is_body<T>::value;

template <class T>
concept body_reader = is_body_reader<T>::value;

} // namespace http::concepts

} // namespace boost::beast

namespace routemon::http {

struct supported_verb
{
  enum supported_verb_t : std::uint8_t
  {
    options,
    delete_,
    get,
    head,
    post,
    put,
  };

  supported_verb_t value;

  supported_verb(supported_verb_t value) : value{value} {}

  static auto from(bhttp::verb v) -> std::optional<supported_verb>
  {
    switch (v)
    {
    case bhttp::verb::options:
      return supported_verb::options;
    case bhttp::verb::delete_:
      return supported_verb::delete_;
    case bhttp::verb::get:
      return supported_verb::get;
    case bhttp::verb::head:
      return supported_verb::head;
    case bhttp::verb::post:
      return supported_verb::post;
    case bhttp::verb::put:
      return supported_verb::put;
    default:
      return std::nullopt;
    }
  }

  operator bhttp::verb() const
  {
    switch (value)
    {
    case supported_verb::options:
      return bhttp::verb::options;
    case supported_verb::delete_:
      return bhttp::verb::delete_;
    case supported_verb::get:
      return bhttp::verb::get;
    case supported_verb::head:
      return bhttp::verb::head;
    case supported_verb::post:
      return bhttp::verb::post;
    case supported_verb::put:
      return bhttp::verb::put;
    }
  }
};

export struct verb_set
{
  bool delete_ : 1 = false;
  bool get : 1 = false;
  bool head : 1 = false;
  bool post : 1 = false;
  bool put : 1 = false;
  bool options : 1 = false;

  auto enable(supported_verb v) -> void
  {
    switch (v.value)
    {
    case supported_verb::delete_:
      delete_ = true;
      break;
    case supported_verb::get:
      get = true;
      break;
    case supported_verb::head:
      head = true;
      break;
    case supported_verb::post:
      post = true;
      break;
    case supported_verb::put:
      put = true;
      break;
    case supported_verb::options:
      options = true;
      break;
    default:;
    }
  }

  auto operator==(verb_set const& rhs) const noexcept -> bool = default;

  auto empty() const -> bool { return *this == verb_set{}; }

  verb_set(std::initializer_list<supported_verb> vs)
  {
    for (auto const v : vs)
      enable(v);
  }

  auto to_string() const -> std::string
  {
    std::ostringstream ss;
    bool wrote = false;
    auto write = [&](bhttp::verb v)
    {
      if (wrote)
        ss << ", ";
      ss << v;
      wrote = true;
    };
    if (delete_)
      write(bhttp::verb::delete_);
    if (get)
      write(bhttp::verb::get);
    if (head)
      write(bhttp::verb::head);
    if (post)
      write(bhttp::verb::post);
    if (put)
      write(bhttp::verb::put);
    if (options)
      write(bhttp::verb::options);
    return ss.str();
  }
};

} // namespace routemon::http