#[macro_use]
extern crate clap;

use std::process::exit;

use extra::option::OptionalExt;
use redox_users::{All, AllGroups, AllUsers, Config};

const _MAN_PAGE: &'static str = /* @MANSTART{groupmod} */
    r#"
NAME
    groupmod - modify group information

SYNOPSYS
    groupmod [ options ] GROUP
    groupmod [ -h | --help ]

DESCRIPTION
    groupmod modifies a user group GROUP in the system's
    redox_users backend.

OPTIONS
    -h, --help
        Print this help page and exit.

    -g, --gid GID
        Change GROUP's group id. GID must be a non-negative
        decimal integer.

        Files with GROUP's old gid will not be updated.

        User's who use the old gid as their primary gid will
        be updated.

    -n, --name NAME
        The name of the group will be set to NAME

AUTHORS
    Wesley Hershberger.
"#; /* @MANEND */

fn main() {
    let args = clap_app!(groupmod =>
        (author: "Wesley Hershberger")
        (about: "Modify users according to the system's redox_users backend")
        (@arg GROUP:          +required    "Modify GROUP")
        (@arg GID:  -g --gid  +takes_value "Change GROUP's group id. See man page for details")
        (@arg NAME: -n --name +takes_value "Change GROUP's name")
    )
    .get_matches();

    let groupname = args.value_of("GROUP").unwrap();

    let mut sys_groups = AllGroups::new(Config::default().writeable(true)).unwrap_or_exit(1);
    {
        let group = sys_groups.get_mut_by_name(groupname).unwrap_or_else(|| {
            eprintln!("groupmod: group not found: {}", groupname);
            exit(1);
        });

        if let Some(gid) = args.value_of("GID") {
            let gid = gid.parse::<usize>().unwrap_or_exit(1);
            // Update users
            let mut sys_users =
                AllUsers::authenticator(Config::default().writeable(true)).unwrap_or_exit(1);
            for user in sys_users.iter_mut() {
                if user.gid == group.gid {
                    user.gid = gid;
                }
            }
            sys_users.save().unwrap_or_exit(1);
            group.gid = gid;
        }

        if let Some(name) = args.value_of("NAME") {
            group.group = name.to_string();
        }
    }

    sys_groups.save().unwrap_or_exit(1);
}