use echo_api::{Priv, Sender, ServiceCtx, Store};

// DEFCON [1-5]: read or set the network defence level. 5 is normal; each lower
// level adds a restriction — 4 freezes channel registrations, 3 freezes all
// registrations, 2 also caps everyone to one session, 1 is a full lockdown that
// turns away new connections. Changing it announces the level to the network.
// Admin-only.
pub fn handle(me: &str, from: &Sender, args: &[&str], ctx: &mut ServiceCtx, db: &mut dyn Store) {
    if !from.privs.has(Priv::Admin) {
        ctx.notice(me, from.uid, "Access denied — DEFCON needs the \x02admin\x02 privilege.");
        return;
    }
    match args.get(1) {
        None => ctx.notice(me, from.uid, format!("The network is at \x02DEFCON {}\x02 — {}.", db.defcon(), describe(db.defcon()))),
        Some(&arg) => match arg.parse::<u8>() {
            Ok(level) if (1..=5).contains(&level) => {
                db.set_defcon(level);
                ctx.notice(me, from.uid, format!("DEFCON set to \x02{level}\x02 — {}.", describe(level)));
                // Let everyone know the posture changed.
                let msg = if level == 5 {
                    "The network is back to normal operations (DEFCON 5).".to_string()
                } else {
                    format!("Network defence level is now \x02DEFCON {level}\x02: {}.", describe(level))
                };
                ctx.global(me, msg);
            }
            _ => ctx.notice(me, from.uid, "Syntax: DEFCON [1-5] (5 = normal, 1 = lockdown)"),
        },
    }
}

fn describe(level: u8) -> &'static str {
    match level {
        5 => "normal operations",
        4 => "channel registrations frozen",
        3 => "all registrations frozen",
        2 => "registrations frozen and sessions capped to one per host",
        _ => "full lockdown, no new connections",
    }
}