use std::{process::Command, time::Duration};

use serde::Deserialize;
use tokio::sync::watch::Sender;

use crate::{Error, Status};

use super::ServiceSpawner;

#[derive(Debug, Clone, Deserialize)]
pub struct Systemd {
    pub service: String,
}

impl ServiceSpawner for Systemd {
    async fn spawn(self, tx: Sender<Status>) -> Result<(), Error> {
        let mut command = Command::new("systemctl");
        command.arg("is-active").arg(&self.service);

        let mut interval = tokio::time::interval(Duration::from_secs(5));
        loop {
            interval.tick().await;

            let status = command.output().map_or_else(Into::into, |o| {
                if o.status.success() {
                    Status::Ok
                } else {
                    let stdout = String::from_utf8_lossy(&o.stdout).trim().to_string();
                    Status::Error(Some(format!("Service state: {}", stdout)))
                }
            });

            tx.send_if_modified(|s| s.update(status));
        }
    }
}