#![feature(impl_trait_in_assoc_type)]

use std::future::{ready, Ready};

use btproto::protocol;
use btrun::{
    actor_name,
    model::{CallMsg, End, TransResult},
};
use serde::{Deserialize, Serialize};

#[derive(Serialize, Deserialize)]
pub struct Ping;

impl CallMsg for Ping {
    type Reply = ();
}

/// Tests that the given variable is of the given type _at compile time_.
macro_rules! assert_type {
    ($var:expr, $ty:ty) => {{
        let _: $ty = $var;
    }};
}

#[test]
fn minimal_syntax() {
    #[derive(Serialize, Deserialize)]
    pub struct Msg;

    protocol! {
        named MinimalTest;
        let server = [Server];
        let client = [Client];
        Client -> End, >service(Server)!Msg;
        Server?Msg -> End;
    }

    let msg: Option<MinimalTestMsgs> = None;
    match msg {
        Some(MinimalTestMsgs::Msg(act)) => assert_type!(act, Msg),
        None => (),
    }

    struct ServerImpl;

    impl Server for ServerImpl {
        actor_name!("minimal_server");

        type HandleMsgFut = Ready<TransResult<Self, End>>;
        fn handle_msg(self, _msg: Msg) -> Self::HandleMsgFut {
            ready(TransResult::Ok(End))
        }
    }

    struct ClientImpl;

    impl Client for ClientImpl {
        actor_name!("minimal_client");

        type OnSendMsgReturn = usize;
        type OnSendMsgFut = Ready<TransResult<Self, (End, usize)>>;
        fn on_send_msg(self) -> Self::OnSendMsgFut {
            ready(TransResult::Ok((End, 42)))
        }
    }
}

#[test]
fn reply() {
    protocol! {
        named ReplyTest;
        let server = [Listening];
        let client = [Client];
        Client -> Client, >service(Listening)!Ping;
        Listening?Ping -> Listening, >Client!Ping::Reply;
    }

    let msg: Option<ReplyTestMsgs> = None;
    match msg {
        Some(ReplyTestMsgs::Ping(ping)) => assert_type!(ping, Ping),
        Some(ReplyTestMsgs::PingReply(reply)) => assert_type!(reply, <Ping as CallMsg>::Reply),
        None => (),
    }

    struct ListeningImpl;

    impl Listening for ListeningImpl {
        actor_name!("reply_server");

        type HandlePingListening = Self;
        type HandlePingFut = Ready<TransResult<Self, (Self, <Ping as CallMsg>::Reply)>>;
        fn handle_ping(self, _msg: Ping) -> Self::HandlePingFut {
            ready(TransResult::Ok((self, ())))
        }
    }

    struct ClientImpl;

    impl Client for ClientImpl {
        actor_name!("reply_client");

        type OnSendPingReturn = ();
        type OnSendPingClient = Self;
        type OnSendPingFut = Ready<TransResult<Self, (Self, ())>>;
        fn on_send_ping(self, _ping: <Ping as CallMsg>::Reply) -> Self::OnSendPingFut {
            ready(TransResult::Ok((self, ())))
        }
    }
}

#[test]
fn client_callback() {
    #[derive(Serialize, Deserialize)]
    pub struct Register;
    #[derive(Serialize, Deserialize)]
    pub struct Completed;

    protocol! {
        named ClientCallback;
        let server = [Listening];
        let worker = [Working];
        let client = [Unregistered, Registered];
        Unregistered -> Registered, >service(Listening)!Register[Registered];
        Listening?Register[Registered] -> Listening, Working[Registered];
        Working[Registered] -> End, >Registered!Completed;
        Registered?Completed -> End;
    }

    let msg: Option<ClientCallbackMsgs> = None;
    match msg {
        Some(ClientCallbackMsgs::Register(msg)) => assert_type!(msg, Register),
        Some(ClientCallbackMsgs::Completed(msg)) => assert_type!(msg, Completed),
        None => (),
    }

    let client_state: Option<ClientState<UnregisteredImpl>> = None;
    match client_state {
        Some(ClientState::Unregistered(state)) => assert_type!(state, UnregisteredImpl),
        Some(ClientState::Registered(state)) => assert_type!(state, RegisteredImpl),
        Some(ClientState::End(state)) => assert_type!(state, End),
        None => (),
    }

    struct UnregisteredImpl;

    impl Unregistered for UnregisteredImpl {
        actor_name!("callback_client");

        type OnSendRegisterReturn = ();
        type OnSendRegisterRegistered = RegisteredImpl;
        type OnSendRegisterFut = Ready<TransResult<Self, (Self::OnSendRegisterRegistered, ())>>;
        fn on_send_register(self) -> Self::OnSendRegisterFut {
            ready(TransResult::Ok((RegisteredImpl, ())))
        }
    }

    struct RegisteredImpl;

    impl Registered for RegisteredImpl {
        type HandleCompletedFut = Ready<TransResult<Self, End>>;
        fn handle_completed(self, _arg: Completed) -> Self::HandleCompletedFut {
            ready(TransResult::Ok(End))
        }
    }

    struct ListeningImpl;

    impl Listening for ListeningImpl {
        actor_name!("callback_server");

        type HandleRegisterListening = ListeningImpl;
        type HandleRegisterWorking = WorkingImpl;
        type HandleRegisterFut = Ready<TransResult<Self, (ListeningImpl, WorkingImpl)>>;
        fn handle_register(self, _arg: Register) -> Self::HandleRegisterFut {
            ready(TransResult::Ok((self, WorkingImpl)))
        }
    }

    struct WorkingImpl;

    impl Working for WorkingImpl {
        actor_name!("callback_worker");

        type OnSendCompletedFut = Ready<TransResult<Self, (End, Completed)>>;
        fn on_send_completed(self) -> Self::OnSendCompletedFut {
            ready(TransResult::Ok((End, Completed)))
        }
    }
}