ops-sat-rs/src/controller.rs

use num_enum::TryFromPrimitive;
use satrs::{
    action::ActionRequest,
    pus::action::{ActionReplyPus, ActionReplyVariant},
    request::{GenericMessage, MessageMetadata},
};
use std::{
    env::temp_dir,
    path::{Path, PathBuf},
    sync::{atomic::AtomicBool, mpsc, Arc},
};

use ops_sat_rs::config::{action_err::INVALID_ACTION_ID, HOME_PATH, STOP_FILE_NAME};

use crate::requests::CompositeRequest;

#[derive(Debug, Clone, Copy, TryFromPrimitive)]
#[repr(u32)]
pub enum ActionId {
    StopExperiment = 1,
}

pub struct ExperimentController {
    pub composite_request_rx: mpsc::Receiver<GenericMessage<CompositeRequest>>,
    pub action_reply_tx: mpsc::Sender<GenericMessage<ActionReplyPus>>,
    pub stop_signal: Arc<AtomicBool>,
    home_path_stop_file: PathBuf,
    tmp_path_stop_file: PathBuf,
}

impl ExperimentController {
    pub fn new(
        composite_request_rx: mpsc::Receiver<GenericMessage<CompositeRequest>>,
        action_reply_tx: mpsc::Sender<GenericMessage<ActionReplyPus>>,
        stop_signal: Arc<AtomicBool>,
    ) -> Self {
        let mut home_path_stop_file = PathBuf::new();
        home_path_stop_file.push(HOME_PATH.as_path());
        home_path_stop_file.push(STOP_FILE_NAME);
        let mut tmp_path_stop_file = temp_dir();
        tmp_path_stop_file.push(STOP_FILE_NAME);
        Self {
            composite_request_rx,
            action_reply_tx,
            stop_signal,
            home_path_stop_file,
            tmp_path_stop_file,
        }
    }
}

impl ExperimentController {
    pub fn perform_operation(&mut self) {
        match self.composite_request_rx.try_recv() {
            Ok(msg) => match msg.message {
                CompositeRequest::Hk(_) => {
                    log::warn!("hk request handling unimplemented")
                }
                CompositeRequest::Action(action_req) => {
                    self.handle_action_request(msg.requestor_info, action_req);
                }
            },
            Err(e) => {
                if e != mpsc::TryRecvError::Empty {
                    log::error!("composite request rx error: {:?}", e);
                }
            }
        }
        self.check_stop_file();
    }

    pub fn handle_action_request(&mut self, requestor: MessageMetadata, action_req: ActionRequest) {
        let action_id = ActionId::try_from(action_req.action_id);
        if action_id.is_err() {
            let result = self.action_reply_tx.send(GenericMessage::new_action_reply(
                requestor,
                action_req.action_id,
                ActionReplyVariant::CompletionFailed {
                    error_code: INVALID_ACTION_ID,
                    params: None,
                },
            ));
            if result.is_err() {
                log::error!("sending action reply failed");
            }
            return;
        }
        let action_id = action_id.unwrap();
        match action_id {
            ActionId::StopExperiment => {
                self.stop_signal
                    .store(true, std::sync::atomic::Ordering::Relaxed);
                let result = self.action_reply_tx.send(GenericMessage::new_action_reply(
                    requestor,
                    action_req.action_id,
                    ActionReplyVariant::Completed,
                ));
                if result.is_err() {
                    log::error!("sending action reply failed");
                }
            }
        }
    }

    pub fn check_stop_file(&self) {
        let check_at_path = |path: &Path| {
            if path.exists() {
                log::warn!(
                    "Detected stop file name at {:?}. Initiating experiment shutdown",
                    path
                );
                // By default, clear the stop file.
                let result = std::fs::remove_file(path);
                if result.is_err() {
                    log::error!(
                        "failed to remove stop file at {:?}: {}",
                        path,
                        result.unwrap_err()
                    );
                }
                self.stop_signal
                    .store(true, std::sync::atomic::Ordering::Relaxed);
            }
        };
        check_at_path(self.tmp_path_stop_file.as_path());
        check_at_path(self.home_path_stop_file.as_path());
    }
}