// Code to handle the nebula worker
// This is an inert version of the nebula worker that does nothing, used when linking to nebula is diabled.
// This is useful if you wish to run your own nebula binary, for example on platforms where CGo does not work.

use crate::config::{load_cdata, NebulaConfig, TFClientConfig};
use crate::daemon::ThreadMessageSender;
use crate::dirs::{nebula_yml};
use log::{debug, error, info};
use std::error::Error;
use std::fs;
use std::sync::mpsc::Receiver;

pub enum NebulaWorkerMessage {
    Shutdown,
    ConfigUpdated,
    WakeUp,
}

fn insert_private_key(instance: &str) -> Result<(), Box<dyn Error>> {
    if !nebula_yml(instance).exists() {
        return Ok(()); // cant insert private key into a file that does not exist - BUT. we can gracefully handle nebula crashing - we cannot gracefully handle this fn failing
    }
    let cdata = load_cdata(instance)?;
    let key = cdata.dh_privkey.ok_or("Missing private key")?;

    let config_str = fs::read_to_string(
        nebula_yml(instance),
    )?;
    let mut config: NebulaConfig = serde_yaml::from_str(&config_str)?;

    config.pki.key = Some(String::from_utf8(key)?);

    debug!("inserted private key into config: {:?}", config);

    let config_str = serde_yaml::to_string(&config)?;
    fs::write(
        nebula_yml(instance),
        config_str,
    )?;

    Ok(())
}


pub fn nebulaworker_main(_config: TFClientConfig, instance: String, _transmitter: ThreadMessageSender, rx: Receiver<NebulaWorkerMessage>) {
    loop {
        match rx.recv() {
            Ok(msg) => match msg {
                NebulaWorkerMessage::WakeUp => {
                    continue;
                },
                NebulaWorkerMessage::Shutdown => {
                    break;
                },
                NebulaWorkerMessage::ConfigUpdated => {
                    info!("our configuration has been updated - reloading");

                    debug!("fixing config...");
                    match insert_private_key(&instance) {
                        Ok(_) => {
                            debug!("config fixed (private-key embedded)");
                        }
                        Err(e) => {
                            error!("unable to fix config: {}", e);
                            error!("nebula thread exiting with error");
                            return;
                        }
                    }
                }
            },
            Err(e) => {
                error!("{}", e);
                break;
            }
        }
    }
}