#include "models/wg2nd.hpp"

#include <emscripten/bind.h>

#include <string>
#include <sstream>

void print_config(std::ostream & ss, wg2nd::SystemdFilespec const & filespec, bool privileged) {
	if(privileged) {
		ss << "touch " << filespec.name << "\n\n";

		ss << "chown root:systemd-network " << filespec.name << "\n\n";
		ss << "chmod 0640 " << filespec.name << "\n\n";
	}

	ss << "cat >" << filespec.name << " <<_EOF\n"
	          << filespec.contents
	          << "_EOF\n";

	ss << "\n";
}

std::string wg2nd_cmdseq(std::string const & interface_name, std::string const & wg_config) {
	std::istringstream wg_stream { wg_config };
	std::ostringstream bash_config_cmds;

	wg2nd::SystemdConfig cfg;
	try {
		cfg = wg2nd::wg2nd(interface_name, wg_stream, "/etc/systemd/network/", {});
	} catch(wg2nd::ParsingException const & e) {
		bash_config_cmds << "parsing error: ";

		if(e.line_no().has_value()) {
			bash_config_cmds << "line " << e.line_no().value() << ": ";
		}

		bash_config_cmds << e.what() << "\n";

		return bash_config_cmds.str();
	} catch(wg2nd::ConfigurationException const & e) {
		bash_config_cmds << "configuration error: " << e.what() << "\n";

		return bash_config_cmds.str();
	}

	bash_config_cmds << "# Disable history to prevent private key leakage\n";
	bash_config_cmds << "set +o history\n";
	bash_config_cmds << "\n";

	bash_config_cmds << "cd /etc/systemd/network\n\n";

	bash_config_cmds << "# Create network device\n";
	print_config(bash_config_cmds, cfg.netdev, false);
	bash_config_cmds << "\n";

	bash_config_cmds << "# Configure network\n";
	print_config(bash_config_cmds, cfg.network, false);
	bash_config_cmds << "\n";

	bash_config_cmds << "# Create and protect private keyfile\n";
	print_config(bash_config_cmds, cfg.private_keyfile, true);
	bash_config_cmds << "\n";

	if(cfg.symmetric_keyfiles.size() > 0) {
		bash_config_cmds << "# Create and protect private preshared keyfile\n";
	}
	for(wg2nd::SystemdFilespec const & spec : cfg.symmetric_keyfiles) {
		print_config(bash_config_cmds, spec, true);
		bash_config_cmds << "\n";
	}

	bash_config_cmds << "# Re-enable history tracking\n";
	bash_config_cmds << "set -o history\n";

	bash_config_cmds << "\n";

	if(cfg.warnings.size() > 0) {
		bash_config_cmds << "# NOTE: the conversion tool emitted warnings.\n";
		for(std::string const & warning : cfg.warnings) {
			bash_config_cmds << "# warning:" << warning << "\n";
		}
	}

	return bash_config_cmds.str();
}


EMSCRIPTEN_BINDINGS(wg2nd) {
	emscripten::function("wg2nd_cmdseq", &wg2nd_cmdseq);
}