module routemon:log$impl;

import :log;

namespace routemon::log {

auto operator<<(std::ostream& os, level lvl) -> std::ostream&
{
  switch (lvl)
  {
  case level::debug:
    os << "dbg";
    break;
  case level::info:
    os << "inf";
    break;
  case level::warn:
    os << "wrn";
    break;
  case level::error:
    os << "err";
    break;
  }
  return os;
}

sink::sink(enum level lvl) : lvl_{lvl} {}

auto sink::level() const -> enum level { return lvl_; }

auto sink::set_level(enum level lvl) -> void { lvl_ = lvl; }

auto sink::write(tmp_message msg) -> void
{
  auto sos = std::osyncstream{os_};
  sos << "[" << msg.lvl;
  if (!msg.component.empty())
    sos << " " << msg.component;
  sos << "] " << msg.txt;
  for (auto const& [k, v] : msg.attrs)
    sos << " " << k << "=" << std::quoted(v);
  sos << std::endl; // we want the flush!
}

auto make_sink(level lvl) -> std::shared_ptr<sink>
{
  return std::shared_ptr<sink>{new sink{lvl}};
}

auto logger::log_at(log::level lvl, std::string_view fmt, std::format_args args)
    -> logger&
{
  if (sink_->level() <= lvl)
    sink_->write(
        sink::tmp_message{
          .lvl = lvl,
          .component = component_,
          .txt = std::vformat(fmt, args),
          .attrs = attrs_,
        });
  return *this;
}

logger::logger(std::shared_ptr<sink> const& sink) : sink_{sink}
{
  if (!sink)
  {
    throw std::invalid_argument{"logger sink may not be null"};
  }
}

auto logger::sub(std::string_view component) const -> logger
{
  auto l = *this;
  if (l.component_.empty())
  {
    l.component_ = component;
  }
  else
  {
    l.component_ += ".";
    l.component_ += component;
  }
  return l;
}

auto logger::with(std::string const& k, std::string&& v) const -> logger
{
  auto l = *this;
  l.attrs_[k] = std::move(v);
  return l;
}

auto logger::with(std::string const& k, std::string_view v) const -> logger
{
  return with(k, std::string{v});
}

} // namespace routemon::log