#include <os/ArgumentParser.h>

#include <dirent.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>

Result<int> luna_main(int argc, char** argv)
{
    StringView pathname;
    bool show_all { false };
    bool show_almost_all { false };

    os::ArgumentParser parser;
    parser.add_description("List files contained in a directory (defaults to '.', the current directory)"_sv);
    parser.add_system_program_info("ls"_sv);
    parser.add_positional_argument(pathname, "directory"_sv, "."_sv);
    parser.add_switch_argument(show_all, 'a', "all"_sv, "also list hidden files (whose filename begins with a dot)"_sv);
    parser.add_switch_argument(show_almost_all, 'A', "almost-all"_sv, "list all files except '.' and '..'"_sv);
    parser.parse(argc, argv);

    DIR* dp = opendir(pathname.chars());
    if (!dp)
    {
        perror("opendir");
        return 1;
    }

    int first_ent = 1;
    do {
        struct dirent* ent = readdir(dp);
        if (!ent) break;
        if (show_almost_all && (!strcmp(ent->d_name, ".") || !strcmp(ent->d_name, ".."))) continue;
        if (!show_all && !show_almost_all && *ent->d_name == '.') continue;
        printf(first_ent ? "%s" : " %s", ent->d_name);
        first_ent = 0;
    } while (1);

    putchar('\n');

    closedir(dp);
    return 0;
}