use super::Cmd;
use crate::unistd;
use clap::{Arg, ArgAction, ArgMatches, Command};
use std::{error::Error, io};

#[derive(Debug, Default)]
pub struct Hostname;

impl Cmd for Hostname {
    fn cli(&self) -> clap::Command {
        Command::new("hostname")
            .author("Nathan Fisher")
            .about("Prints the name of the current host. The super-user can set the host name by supplying an argument.")
            .args([
                Arg::new("NAME")
                    .help("name to set"),
                Arg::new("STRIP")
                    .help("Removes any domain information from the printed name.")
                    .short('s')
                    .long("strip")
                    .action(ArgAction::SetTrue)
            ])
    }

    fn run(&self, matches: &ArgMatches) -> Result<(), Box<dyn Error>> {
        if let Some(name) = matches.get_one::<String>("NAME") {
            unistd::sethostname(name)?;
            Ok(())
        } else {
            let hostname = unistd::gethostname()?;
            if matches.get_flag("STRIP") {
                println!(
                    "{}",
                    if let Some(s) = hostname.split('.').next() {
                        s
                    } else {
                        return Err(io::Error::new(
                            io::ErrorKind::Other,
                            "hostname: missing operand",
                        )
                        .into());
                    }
                );
            } else {
                println!("{hostname}");
            }
            Ok(())
        }
    }

    fn path(&self) -> Option<crate::Path> {
        Some(crate::Path::Bin)
    }
}