// This source code is released into the public domain.
export module nihil.config:write;

import nihil.std;
import nihil.error;
import nihil.monad;
import nihil.posix;
import nihil.ucl;
import :option;
import :store;

namespace nihil::config {

// Write all config values (except defaults) to disk.
export [[nodiscard]] auto
write_to(std::filesystem::path const &filename) -> std::expected<void, error>
{
	auto uclconfig = ucl::map<ucl::object>();

	// Add all the options to the UCL object.
	for (auto const &option : store::get().all()) {
		if (option->is_default())
			continue;

		auto uobj = co_await option->ucl();
		uclconfig.insert({option->name(), uobj});
	}

	auto ucl_text = std::format("{:c}", uclconfig);
	co_await safe_write_file(filename, ucl_text);
	co_return {};
}

}; // namespace nihil::config