morethantext/src/queue.rs

use crate::{client::Request, field::Field};
use std::{
    collections::HashMap,
    sync::{mpsc::Sender, Arc, RwLock},
};
use uuid::Uuid;

#[derive(Clone, Debug, Eq, Hash, PartialEq)]
pub enum MsgType {
    ClientRequest,
    Document,
    DocumentRequest,
    Session,
    SessionValidate,
    Time,
}

#[derive(Clone)]
pub struct Message {
    id: Uuid,
    class: MsgType,
    data: HashMap<String, Field>,
}

impl Message {
    pub fn new(msg_type: MsgType) -> Self {
        Self {
            id: Uuid::new_v4(),
            class: msg_type,
            data: HashMap::new(),
        }
    }

    pub fn reply(&self, data: MsgType) -> Message {
        Self {
            id: self.id.clone(),
            class: data,
            data: HashMap::new(),
        }
    }

    pub fn get_class(&self) -> &MsgType {
        &self.class
    }

    pub fn add_data<S, F>(&mut self, name: S, data: F)
    where
        S: Into<String>,
        F: Into<Field>,
    {
        self.data.insert(name.into(), data.into());
    }

    pub fn get_data(&self, name: &str) -> Option<&Field> {
        self.data.get(name)
    }

    pub fn get_id(&self) -> Uuid {
        self.id.clone()
    }
}

impl From<Request> for Message {
    fn from(value: Request) -> Self {
        let mut msg = Message::new(MsgType::ClientRequest);
        match value.session {
            Some(id) => msg.add_data("sess_id", id),
            None => {}
        }
        msg
    }
}

#[cfg(test)]
mod messages {
    use super::*;
    use crate::client::requests::{get_root_document, get_root_document_eith_session};

    #[test]
    fn new_message() {
        let msg = Message::new(MsgType::SessionValidate);
        match msg.class {
            MsgType::SessionValidate => (),
            _ => unreachable!("new defaults to noop"),
        }
        assert!(msg.data.is_empty());
    }

    #[test]
    fn message_ids_are_random() {
        let mut ids: Vec<Uuid> = Vec::new();
        for _ in 0..10 {
            let msg = Message::new(MsgType::SessionValidate);
            let id = msg.id.clone();
            assert!(!ids.contains(&id), "{} is a duplicate", id);
            ids.push(id);
        }
    }

    #[test]
    fn create_reply() {
        let id = Uuid::new_v4();
        let mut msg = Message::new(MsgType::SessionValidate);
        msg.id = id.clone();
        msg.add_data("test", "test");
        let data = MsgType::ClientRequest;
        let result = msg.reply(data);
        assert_eq!(result.id, id);
        match result.class {
            MsgType::ClientRequest => {}
            _ => unreachable!("should have been a registration request"),
        }
        assert!(result.data.is_empty());
    }

    #[test]
    fn get_message_type() {
        let msg = Message::new(MsgType::SessionValidate);
        match msg.get_class() {
            MsgType::SessionValidate => {}
            _ => unreachable!("should have bneen noopn"),
        }
    }

    #[test]
    fn add_data() {
        let mut msg = Message::new(MsgType::SessionValidate);
        let one = "one";
        let two = "two".to_string();
        msg.add_data(one, one);
        msg.add_data(two.clone(), two.clone());
        assert_eq!(msg.get_data(one).unwrap().to_string(), one);
        assert_eq!(msg.get_data(&two).unwrap().to_string(), two);
    }

    #[test]
    fn get_message_id() {
        let msg = Message::new(MsgType::Session);
        assert_eq!(msg.get_id(), msg.id);
    }

    #[test]
    fn from_request_no_session() {
        let req = get_root_document();
        let msg: Message = req.into();
        assert!(
            msg.get_data("sess_id").is_none(),
            "should not have a session id"
        )
    }

    #[test]
    fn from_request_with_session() {
        let id = Uuid::new_v4();
        let req = get_root_document_eith_session(id.clone());
        let msg: Message = req.into();
        match msg.get_data("sess_id") {
            Some(result) => assert_eq!(result.to_uuid().unwrap(), id),
            None => unreachable!("should return an id"),
        }
    }
}

#[derive(Clone)]
pub struct Queue {
    store: Arc<RwLock<HashMap<MsgType, Vec<Sender<Message>>>>>,
}

impl Queue {
    pub fn new() -> Self {
        Self {
            store: Arc::new(RwLock::new(HashMap::new())),
        }
    }

    pub fn add(&self, tx: Sender<Message>, msg_types: Vec<MsgType>) {
        let mut store = self.store.write().unwrap();
        for msg_type in msg_types.into_iter() {
            if !store.contains_key(&msg_type) {
                store.insert(msg_type.clone(), Vec::new());
            }
            let senders = store.get_mut(&msg_type).unwrap();
            senders.push(tx.clone());
        }
    }

    pub fn send(&self, msg: Message) -> Result<(), String> {
        let store = self.store.read().unwrap();
        match store.get(&msg.get_class()) {
            Some(senders) => {
                for sender in senders.into_iter() {
                    sender.send(msg.clone()).unwrap();
                }
                Ok(())
            }
            None => Err(format!("no listeners for {:?}", msg.get_class())),
        }
    }
}

#[cfg(test)]
mod queues {
    use super::*;
    use std::{
        sync::mpsc::{channel, RecvTimeoutError},
        time::Duration,
    };

    static TIMEOUT: Duration = Duration::from_millis(500);

    #[test]
    fn create_queue() {
        let queue = Queue::new();
        let (tx1, rx1) = channel();
        let (tx2, rx2) = channel();
        queue.add(tx1, [MsgType::SessionValidate].to_vec());
        queue.add(tx2, [MsgType::SessionValidate].to_vec());
        queue.send(Message::new(MsgType::SessionValidate)).unwrap();
        rx1.recv().unwrap();
        rx2.recv().unwrap();
    }

    #[test]
    fn messages_are_routed() {
        let queue = Queue::new();
        let (tx1, rx1) = channel();
        let (tx2, rx2) = channel();
        queue.add(tx1, [MsgType::SessionValidate].to_vec());
        queue.add(tx2, [MsgType::Session].to_vec());
        queue.send(Message::new(MsgType::SessionValidate)).unwrap();
        let result = rx1.recv().unwrap();
        match result.get_class() {
            MsgType::SessionValidate => {}
            _ => unreachable!(
                "received {:?}, should have been session vvalidate",
                result.get_class()
            ),
        }
        match rx2.recv_timeout(TIMEOUT) {
            Ok(_) => unreachable!("should not have received anything"),
            Err(err) => match err {
                RecvTimeoutError::Timeout => {}
                _ => unreachable!("{:?}", err),
            },
        }
        queue.send(Message::new(MsgType::Session)).unwrap();
        let result = rx2.recv().unwrap();
        match result.get_class() {
            MsgType::Session => {}
            _ => unreachable!(
                "received {:?}, should have been session vvalidate",
                result.get_class()
            ),
        }
        match rx1.recv_timeout(TIMEOUT) {
            Ok(_) => unreachable!("should not have received anything"),
            Err(err) => match err {
                RecvTimeoutError::Timeout => {}
                _ => unreachable!("{:?}", err),
            },
        }
    }

    #[test]
    fn assign_sender_multiple_message_types() {
        let queue = Queue::new();
        let (tx, rx) = channel();
        queue.add(tx, [MsgType::Session, MsgType::SessionValidate].to_vec());
        queue.send(Message::new(MsgType::SessionValidate)).unwrap();
        let msg = rx.recv().unwrap();
        assert_eq!(msg.get_class(), &MsgType::SessionValidate);
        queue.send(Message::new(MsgType::Session)).unwrap();
        let msg = rx.recv().unwrap();
        assert_eq!(msg.get_class(), &MsgType::Session);
    }

    #[test]
    fn unassigned_message_should_return_error() {
        let queue = Queue::new();
        match queue.send(Message::new(MsgType::Session)) {
            Ok(_) => unreachable!("should return error"),
            Err(_) => {}
        }
    }
}