smartbotic/lib/common/config_arg.hpp

#pragma once

#include <filesystem>
#include <string>

namespace smartbotic::common {

struct ConfigArg {
    std::filesystem::path path;

    /**
     * True when the caller named a config file on the command line, false when
     * the built-in default path is being used.
     *
     * The distinction decides what a missing file means. Falling back to
     * defaults is reasonable when nobody asked for a particular file; it is
     * never reasonable when someone did, because the settings they meant to
     * apply - database address, project namespace, ports - would be silently
     * replaced by other values.
     */
    bool explicitly_given = false;
};

/**
 * Read the config file location from a service's command line.
 *
 * Accepts, in order of preference:
 *   --config <path>     --config=<path>
 *   -c <path>           -c=<path>
 *   <path>              (bare first argument, the original form)
 *
 * The flag forms exist because the packaged systemd units have always passed
 * "--config /etc/.../webserver.json", while the services only ever read
 * argv[1] as a path. That mismatch made every .deb install run on built-in
 * defaults with nothing but a warning to say so.
 *
 * Unknown arguments are ignored rather than rejected, so this stays additive
 * for anything else a deployment may already be passing.
 */
ConfigArg parseConfigArg(int argc, char* argv[], const std::filesystem::path& default_path);

}  // namespace smartbotic::common