morethantext/src/message.rs

use std::{
    collections::HashMap,
    sync::{
        mpsc::{channel, Receiver, Sender},
        Arc, RwLock,
    },
    thread::spawn,
};
use uuid::Uuid;

#[derive(Clone, Debug)]
enum MTTError {
    DocumentAlreadyExists(String),
    DocumentNotFound(String),
    RouteNoListeners,
}

#[derive(Clone, Debug, Eq, Hash, PartialEq)]
enum Action {
    Create,
    Query,
    //
    NewDocumentType,
    Reply,
    Update,
}

impl From<MsgAction> for Action {
    fn from(value: MsgAction) -> Self {
        match value {
            MsgAction::Create(_) => Action::Create,
            MsgAction::Query(_) => Action::Query,
        }
    }
}

impl From<&MsgAction> for Action {
    fn from(value: &MsgAction) -> Self {
        let action = value.clone();
        Self::from(action)
    }
}

#[derive(Clone, Debug, Eq, Hash, PartialEq)]
enum NameID {
    ID(Uuid),
    Name(String),
}

impl From<&str> for NameID {
    fn from(value: &str) -> Self {
        Self::Name(value.to_string())
    }
}

impl From<String> for NameID {
    fn from(value: String) -> Self {
        Self::Name(value)
    }
}

impl From<Uuid> for NameID {
    fn from(value: Uuid) -> Self {
        Self::ID(value)
    }
}

impl From<&NameID> for NameID {
    fn from(value: &NameID) -> Self {
        value.clone()
    }
}

#[derive(Clone)]
enum MsgAction {
    Create(DocDef),
    Query(Access),
}

#[derive(Clone)]
struct Message {
    msg_id: Uuid,
    document_id: NameID,
    action: MsgAction,
}

impl Message {
    fn new<D>(doc_id: D, action: MsgAction) -> Self
    where
        D: Into<NameID>,
    {
        Self {
            msg_id: Uuid::new_v4(),
            document_id: doc_id.into(),
            action: action,
        }
    }

    fn get_message_id(&self) -> &Uuid {
        &self.msg_id
    }

    fn get_document_id(&self) -> &NameID {
        &self.document_id
    }

    fn get_action(&self) -> &MsgAction {
        &self.action
    }
}

#[cfg(test)]
mod messages {
    use super::*;

    #[test]
    fn can_the_document_be_a_stringi_reference() {
        let dts = ["one", "two"];
        for document in dts.into_iter() {
            let msg = Message::new(document, MsgAction::Create(DocDef::new()));
            match msg.get_document_id() {
                NameID::ID(_) => unreachable!("should have been a string id"),
                NameID::Name(data) => assert_eq!(data, document),
            }
            match msg.get_action() {
                MsgAction::Create(_) => {}
                _ => unreachable!("should have been a create document"),
            }
        }
    }

    #[test]
    fn can_the_document_be_a_string() {
        let dts = ["one".to_string(), "two".to_string()];
        for document in dts.into_iter() {
            let msg = Message::new(document.clone(), MsgAction::Query(Access::new()));
            match msg.get_document_id() {
                NameID::ID(_) => unreachable!("should have been a string id"),
                NameID::Name(data) => assert_eq!(data, &document),
            }
            match msg.get_action() {
                MsgAction::Query(_) => {}
                _ => unreachable!("should have been an access query"),
            }
        }
    }

    #[test]
    fn can_the_document_be_an_id() {
        let document = Uuid::new_v4();
        let msg = Message::new(document.clone(), MsgAction::Query(Access::new()));
        match msg.get_document_id() {
            NameID::ID(data) => assert_eq!(data, &document),
            NameID::Name(_) => unreachable!("should have been an id"),
        }
        match msg.get_action() {
            MsgAction::Query(_) => {}
            _ => unreachable!("should have been an access query"),
        }
    }

    #[test]
    fn is_the_message_id_random() {
        let mut ids: Vec<Uuid> = Vec::new();
        for _ in 0..5 {
            let msg = Message::new("tester", MsgAction::Create(DocDef::new()));
            let id = msg.get_message_id().clone();
            assert!(!ids.contains(&id), "{:?} containts  {}", ids, id);
            ids.push(id);
        }
    }
}

#[derive(Clone, Debug)]
enum Include<T> {
    All,
    Some(T),
}

impl<T: PartialEq> PartialEq for Include<T> {
    fn eq(&self, other: &Self) -> bool {
        match self {
            Include::All => true,
            Include::Some(data) => match other {
                Include::All => true,
                Include::Some(other_data) => data == other_data,
            },
        }
    }
}

#[cfg(test)]
mod includes {
    use super::*;

    #[test]
    fn does_all_equal_evberything() {
        let a: Include<isize> = Include::All;
        let b: Include<isize> = Include::Some(5);
        let c: Include<isize> = Include::Some(7);
        assert!(a == a, "all should equal all");
        assert!(a == b, "all should equal some");
        assert!(b == a, "some should equal all");
        assert!(b == b, "same some should equal");
        assert!(b != c, "different somes do not equal");
    }
}

#[derive(Eq, Hash, PartialEq)]
struct RouteID {
    action: Option<Action>,
    doc_type: Option<Uuid>,
    msg_id: Option<Uuid>,
}

impl From<Route> for RouteID {
    fn from(value: Route) -> Self {
        Self {
            action: match value.action {
                Include::All => None,
                Include::Some(action) => Some(action.clone()),
            },
            doc_type: match value.doc_type {
                Include::All => None,
                Include::Some(doc) => Some(doc.clone()),
            },
            msg_id: match value.msg_id {
                Include::All => None,
                Include::Some(id) => Some(id.clone()),
            },
        }
    }
}

#[derive(Clone, Debug, PartialEq)]
struct Route {
    action: Include<Action>,
    doc_type: Include<Uuid>,
    msg_id: Include<Uuid>,
}

impl Route {
    fn new(msg_id: Include<Uuid>, doc: Include<Uuid>, action: Include<Action>) -> Self {
        Self {
            action: action,
            doc_type: doc,
            msg_id: msg_id,
        }
    }
}

impl From<RouteID> for Route {
    fn from(value: RouteID) -> Self {
        Self {
            action: match value.action {
                Some(data) => Include::Some(data.clone()),
                None => Include::All,
            },
            doc_type: match value.doc_type {
                Some(doc) => Include::Some(doc.clone()),
                None => Include::All,
            },
            msg_id: match value.msg_id {
                Some(msg) => Include::Some(msg.clone()),
                None => Include::All,
            },
        }
    }
}

impl From<&RouteID> for Route {
    fn from(value: &RouteID) -> Self {
        Self {
            action: match &value.action {
                Some(data) => Include::Some(data.clone()),
                None => Include::All,
            },
            doc_type: match &value.doc_type {
                Some(doc) => Include::Some(doc.clone()),
                None => Include::All,
            },
            msg_id: match &value.msg_id {
                Some(msg) => Include::Some(msg.clone()),
                None => Include::All,
            },
        }
    }
}

#[cfg(test)]
mod roiutes {
    use super::*;

    #[test]
    fn can_a_route_set_action() {
        let actions = [Action::Query, Action::Reply];
        for action in actions.into_iter() {
            let route = Route::new(Include::All, Include::All, Include::Some(action.clone()));
            match route.msg_id {
                Include::All => {}
                Include::Some(_) => unreachable!("should have been all"),
            }
            match route.doc_type {
                Include::All => {}
                Include::Some(_) => unreachable!("should have been all"),
            }
            match route.action {
                Include::All => unreachable!("should be a specific value"),
                Include::Some(result) => assert_eq!(result, action),
            }
        }
    }

    #[test]
    fn can_route_set_document_by_name() {
        let doc_id = Uuid::new_v4();
        let route = Route::new(Include::All, Include::Some(doc_id.clone()), Include::All);
        match route.msg_id {
            Include::All => {}
            Include::Some(_) => unreachable!("should have been all"),
        }
        match route.doc_type {
            Include::All => unreachable!("should be a specific value"),
            Include::Some(result) => assert_eq!(result, doc_id),
        }
        match route.action {
            Include::All => {}
            Include::Some(_) => unreachable!("should have been all"),
        }
    }

    #[test]
    fn can_route_set_document_by_id() {
        let id = Uuid::new_v4();
        let route = Route::new(Include::All, Include::Some(id.clone()), Include::All);
        match route.msg_id {
            Include::All => {}
            Include::Some(_) => unreachable!("should have been all"),
        }
        match route.doc_type {
            Include::All => unreachable!("should be a specific value"),
            Include::Some(result) => assert_eq!(result, id),
        }
        match route.action {
            Include::All => {}
            Include::Some(_) => unreachable!("should have been all"),
        }
    }

    #[test]
    fn can_route_be_set_by_message_id() {
        let id = Uuid::new_v4();
        let route = Route::new(Include::Some(id.clone()), Include::All, Include::All);
        match route.msg_id {
            Include::All => unreachable!("should be a specific value"),
            Include::Some(result) => assert_eq!(result, id),
        }
        match route.doc_type {
            Include::All => {}
            Include::Some(_) => unreachable!("should have been all"),
        }
        match route.action {
            Include::All => {}
            Include::Some(_) => unreachable!("should have been all"),
        }
    }
}

struct QueueData {
    senders: HashMap<Uuid, Sender<Message>>,
    names: HashMap<String, Uuid>,
    routes: HashMap<RouteID, Vec<Uuid>>,
}

impl QueueData {
    fn new() -> Self {
        Self {
            senders: HashMap::new(),
            names: HashMap::new(),
            routes: HashMap::new(),
        }
    }

    fn get_doc_id<N>(&self, nameid: N) -> Result<Uuid, MTTError>
    where
        N: Into<NameID>,
    {
        let sender_id = match nameid.into() {
            NameID::Name(name) => match self.names.get(&name) {
                Some(id) => id.clone(),
                None => return Err(MTTError::DocumentNotFound(name.clone())),
            },
            NameID::ID(id) => id.clone(),
        };
        if self.senders.contains_key(&sender_id) {
            Ok(sender_id)
        } else {
            Err(MTTError::DocumentNotFound(sender_id.to_string()))
        }
    }

    fn register(&mut self, name: String, tx: Sender<Message>) -> Result<Uuid, MTTError> {
        match self.get_doc_id(name.as_str()) {
            Ok(_) => return Err(MTTError::DocumentAlreadyExists(name)),
            Err(_) => (),
        }
        let mut id = Uuid::new_v4();
        while self.senders.contains_key(&id) {
            id = Uuid::new_v4();
        }
        self.senders.insert(id.clone(), tx);
        self.names.insert(name, id.clone());
        Ok(id)
    }

    fn send(&self, msg: Message) -> Result<(), MTTError> {
        let doc_id: Include<Uuid> = match self.get_doc_id(msg.get_document_id()) {
            Ok(id) => Include::Some(id.clone()),
            Err(err) => {
                let action: Action = msg.get_action().into();
                if action == Action::Create {
                    Include::Some(Uuid::nil())
                } else {
                    return Err(err);
                }
            }
        };
        let route = Route::new(
            Include::Some(msg.get_message_id().clone()),
            doc_id,
            Include::Some(msg.get_action().into()),
        );
        for (send_route, send_ids) in self.routes.iter() {
            if route == send_route.into() {
                for send_id in send_ids {
                    let tx = self.senders.get(&send_id).unwrap();
                    tx.send(msg.clone()).unwrap();
                }
            }
        }
        Ok(())
    }

    fn add_route<N>(
        &mut self,
        sender_id: &Uuid,
        doc_type: Include<N>,
        action: Action,
    ) -> Result<(), MTTError>
    where
        N: Into<NameID>,
    {
        let doc_id = match doc_type {
            Include::Some(data) => match self.get_doc_id(data) {
                Ok(id) => Include::Some(id.clone()),
                Err(err) => return Err(err),
            },
            Include::All => Include::All,
        };
        let route = Route::new(Include::All, doc_id, Include::Some(action));
        let route_id = route.into();
        match self.routes.get_mut(&route_id) {
            Some(mut senders) => senders.push(sender_id.clone()),
            None => {
                self.routes
                    .insert(route_id.into(), [sender_id.clone()].to_vec());
            }
        }
        Ok(())
    }
}

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

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

    #[test]
    fn can_a_new_document_type_be_rgistered() {
        let name = Uuid::new_v4().to_string();
        let action = Action::Query;
        let (tx, rx) = channel();
        let mut queuedata = QueueData::new();
        let id = queuedata.register(name.clone(), tx).unwrap();
        queuedata.add_route(&id, Include::Some(name.clone()), action);
        let msg = Message::new(name.clone(), MsgAction::Query(Access::new()));
        queuedata.send(msg.clone()).unwrap();
        let result = rx.recv_timeout(TIMEOUT).unwrap();
        assert_eq!(result.get_message_id(), msg.get_message_id());
        let msg = Message::new(id.clone(), MsgAction::Query(Access::new()));
        queuedata.send(msg.clone()).unwrap();
        let result = rx.recv_timeout(TIMEOUT).unwrap();
        assert_eq!(result.get_message_id(), msg.get_message_id());
    }

    #[test]
    fn does_a_bad_document_name_fail() {
        let docname = Uuid::new_v4().to_string();
        let queuedata = QueueData::new();
        let msg = Message::new(docname.clone(), MsgAction::Query(Access::new()));
        match queuedata.send(msg) {
            Ok(_) => unreachable!("should have been an error"),
            Err(data) => match data {
                MTTError::DocumentNotFound(doc) => assert_eq!(doc, docname),
                _ => unreachable!("should have been a not found error"),
            },
        }
    }

    #[test]
    fn should_error_on_duplicate_name_registration() {
        let name = Uuid::new_v4().to_string();
        let (tx1, _) = channel();
        let (tx2, _) = channel();
        let mut queuedata = QueueData::new();
        queuedata.register(name.clone(), tx1).unwrap();
        match queuedata.register(name.clone(), tx2) {
            Ok(_) => unreachable!("should have been an weeoe"),
            Err(data) => match data {
                MTTError::DocumentAlreadyExists(output) => assert_eq!(output, name),
                _ => unreachable!("should have been an already exists errorr"),
            },
        }
    }

    #[test]
    fn is_send_okay_if_no_one_is_listening() {
        let mut queuedata = QueueData::new();
        let name = "something";
        let (tx, _) = channel();
        queuedata.register(name.to_string(), tx).unwrap();
        let msg = Message::new("something", MsgAction::Create(DocDef::new()));
        match queuedata.send(msg) {
            Ok(_) => {}
            Err(err) => unreachable!("got {:?}: should not error", err),
        }
    }

    #[test]
    fn can_certain_messages_be_ignored() {
        let mut queuedata = QueueData::new();
        let doctype = "test";
        let (tx, rx) = channel();
        let id = queuedata.register(doctype.to_string(), tx).unwrap();
        queuedata.add_route(&id, Include::Some(doctype.to_string()), Action::Query);
        let msg = Message::new(doctype, MsgAction::Query(Access::new()));
        queuedata.send(msg.clone()).unwrap();
        let result = rx.recv_timeout(TIMEOUT).unwrap();
        assert_eq!(result.get_message_id(), msg.get_message_id());
        let msg = Message::new(doctype, MsgAction::Query(Access::new()));
        match rx.recv_timeout(TIMEOUT) {
            Ok(_) => unreachable!("should timeout"),
            Err(err) => match err {
                RecvTimeoutError::Timeout => {}
                _ => unreachable!("should timeout"),
            },
        }
    }

    #[test]
    fn can_more_than_one_document_respond() {
        let mut queuedata = QueueData::new();
        let name1 = "task";
        let name2 = "work";
        let action = MsgAction::Query(Access::new());
        let (tx1, rx1) = channel();
        let (tx2, rx2) = channel();
        let id1 = queuedata.register(name1.to_string(), tx1).unwrap();
        let id2 = queuedata.register(name2.to_string(), tx2).unwrap();
        queuedata.add_route(
            &id1,
            Include::Some(name1.to_string()),
            action.clone().into(),
        );
        queuedata.add_route(
            &id2,
            Include::Some(name1.to_string()),
            action.clone().into(),
        );
        let msg = Message::new(name1, action.clone());
        queuedata.send(msg.clone()).unwrap();
        let result1 = rx1.recv_timeout(TIMEOUT).unwrap();
        let result2 = rx2.recv_timeout(TIMEOUT).unwrap();
        assert_eq!(result1.get_message_id(), msg.get_message_id());
        assert_eq!(result1.get_message_id(), result2.get_message_id());
    }

    #[test]
    fn can_a_route_be_generally_set() {
        let mut queuedata = QueueData::new();
        let doctype = "something";
        let action = MsgAction::Query(Access::new());
        let (tx, rx) = channel();
        let id = queuedata.register(doctype.to_string(), tx).unwrap();
        let data: Include<String> = Include::All;
        queuedata.add_route(&id, data, action.clone().into());
        let msg = Message::new(doctype, action);
        queuedata.send(msg.clone()).unwrap();
        let result = rx.recv_timeout(TIMEOUT).unwrap();
        assert_eq!(result.get_message_id(), msg.get_message_id());
    }
}

#[derive(Clone)]
struct Queue {
    queue_data: Arc<RwLock<QueueData>>,
}

impl Queue {
    fn new() -> Self {
        Self {
            queue_data: Arc::new(RwLock::new(QueueData::new())),
        }
    }

    fn register(&mut self, name: String, tx: Sender<Message>) -> Result<Uuid, MTTError> {
        let mut queuedata = self.queue_data.write().unwrap();
        queuedata.register(name, tx)
    }

    fn send(&self, msg: Message) -> Result<(), MTTError> {
        let queuedata = self.queue_data.read().unwrap();
        queuedata.send(msg)
    }

    fn add_route<N>(
        &mut self,
        sender_id: &Uuid,
        doc_type: Include<N>,
        action: Action,
    ) -> Result<(), MTTError>
    where
        N: Into<NameID>,
    {
        let mut queuedata = self.queue_data.write().unwrap();
        queuedata.add_route(sender_id, doc_type, action)
    }
}

#[cfg(test)]
mod queues {
    use super::*;

    #[test]
    fn create_a_queue() {
        Queue::new();
    }
}

struct CreateDoc {
    queue: Queue,
    rx: Receiver<Message>,
}

impl CreateDoc {
    fn new(queue: Queue, rx: Receiver<Message>) -> Self {
        Self {
            queue: queue,
            rx: rx,
        }
    }

    fn start(mut queue: Queue) {
        let (tx, rx) = channel();
        let id = queue.register("document".to_string(), tx).unwrap();
        let nameid: Include<NameID> = Include::All;
        queue.add_route(&id, nameid, Action::Create);
        let doc = CreateDoc::new(queue, rx);
        spawn(move || {
            doc.listen();
        });
    }

    fn listen(&self) {
        loop {
            let msg = self.rx.recv().unwrap();
            match msg.get_document_id() {
                NameID::Name(name) => Document::start(self.queue.clone(), name.clone()),
                NameID::ID(_) => unreachable!("should be a name"),
            }
        }
    }
}

#[derive(Clone)]
struct DocDef;

impl DocDef {
    fn new() -> Self {
        Self {}
    }
}

#[derive(Clone)]
struct Access;

impl Access {
    fn new() -> Self {
        Self {}
    }
}

struct Document {
    queue: Queue,
    rx: Receiver<Message>,
}

impl Document {
    fn new(queue: Queue, rx: Receiver<Message>) -> Self {
        Self {
            queue: queue,
            rx: rx,
        }
    }

    fn start(mut queue: Queue, name: String) {
        let (tx, rx) = channel();
        queue.register(name, tx);
        let doc = Document::new(queue, rx);
        spawn(move || {
            doc.listen();
        });
    }

    fn listen(&self) {
        loop {
            self.rx.recv().unwrap();
        }
    }
}

#[cfg(test)]
mod createdocs {
    use super::*;
    use std::{thread::sleep, time::Duration};

    #[test]
    fn create_document_creation() {
        let queue = Queue::new();
        CreateDoc::start(queue.clone());
        let name = "project";
        let msg = Message::new(name, MsgAction::Create(DocDef::new()));
        queue.send(msg).unwrap();
        sleep(Duration::from_secs(1));
        let msg2 = Message::new(name, MsgAction::Query(Access::new()));
        queue.send(msg2).unwrap();
    }
}