use anyhow::Context;
use clap::Parser;
use roowho2_lib::{proto::WhodUserEntry, server::rwhod::RwhodClientProxy};

/// Check who is logged in on local machines.
///
/// The `rwho` command produces output similar to `who`, but for all machines on the local network.
/// If no report has been received from a machine for 11 minutes then rwho assumes the machine is down,
/// and does not report users last known to be logged into that machine.
///
/// If a users hasn't typed to the system for a minute or more, then rwho reports this idle time.
/// If a user hasn't typed to the system for an hour or more,
/// then the user will be omitted from the output of `rwho` unless the `-a` flag is given.
#[derive(Debug, Parser)]
pub struct Args {
    /// Print all machines responding even if no one is currently logged in
    #[arg(long, short)]
    all: bool,

    /// Print the output with the old formatting
    #[arg(long, short)]
    old: bool,

    /// Output in JSON format
    #[arg(long, short)]
    json: bool,
}

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let args = Args::parse();

    let mut conn = zlink::unix::connect("/run/roowho2/roowho2.varlink")
        .await
        .expect("Failed to connect to rwhod server");

    let reply = conn
        .rwho(args.all)
        .await
        .context("Failed to send rwho request")?
        .map_err(|e| anyhow::anyhow!("Server returned an error for rwho request: {:?}", e))?;

    if args.json {
        println!("{}", serde_json::to_string_pretty(&reply).unwrap());
    } else if args.old {
        for (hostname, user) in &reply {
            let entry_str = old_format_user_entry(hostname, user);
            println!("{}", entry_str);
        }
    } else {
        for (hostname, user) in &reply {
            let entry_str = old_format_user_entry(hostname, user);
            println!("{}", entry_str);
        }
    }

    Ok(())
}

fn old_format_user_entry(hostname: &str, user: &WhodUserEntry) -> String {
    let idle_str = {
        let hours = user.idle_time.num_hours().min(99);
        let minutes = user.idle_time.num_minutes() % 60;
        format!(
            "{:>2}:{:02}",
            if hours < 0 {
                "".to_string()
            } else {
                hours.to_string()
            },
            minutes
        )
    };

    format!(
        "{:<8} {:<8}:{:<8} {} {}",
        user.user_id,
        hostname,
        user.tty,
        user.login_time.format("%b %d %H:%M"),
        idle_str,
    )
}

// larseie  hildring:pts/10 Jan  5 14:53 :01