moq-transport 0.14.2

// SPDX-FileCopyrightText: 2024-2026 Cloudflare Inc., Luke Curley, Mike English and contributors
// SPDX-FileCopyrightText: 2023-2024 Luke Curley and contributors
// SPDX-License-Identifier: MIT OR Apache-2.0

use std::ops;

use crate::coding::{ReasonPhrase, TrackNamespace};
use crate::watch::State;
use crate::{message, serve::ServeError};

use super::{AnnounceInfo, Subscriber};

// There's currently no feedback from the peer, so the shared state is empty.
// If Unannounce contained an error code then we'd be talking.
#[derive(Default)]
struct AnnouncedState {}

pub struct Announced {
    session: Subscriber,
    state: State<AnnouncedState>,

    pub info: AnnounceInfo,

    ok: bool,
    error: Option<ServeError>,
}

impl Announced {
    pub(super) fn new(
        session: Subscriber,
        request_id: u64,
        namespace: TrackNamespace,
    ) -> (Announced, AnnouncedRecv) {
        let info = AnnounceInfo {
            request_id,
            namespace,
        };

        let (send, recv) = State::default().split();
        let send = Self {
            session,
            info,
            ok: false,
            error: None,
            state: send,
        };
        let recv = AnnouncedRecv { _state: recv };

        (send, recv)
    }

    // Send an ANNOUNCE_OK
    pub fn ok(&mut self) -> Result<(), ServeError> {
        if self.ok {
            return Err(ServeError::Duplicate);
        }

        self.session.send_message(message::PublishNamespaceOk {
            id: self.info.request_id,
        });

        self.ok = true;

        Ok(())
    }

    pub async fn closed(&self) -> Result<(), ServeError> {
        loop {
            // Wow this is dumb and yet pretty cool.
            // Basically loop until the state changes and exit when Recv is dropped.
            self.state
                .lock()
                .modified()
                .ok_or(ServeError::Cancel)?
                .await;
        }
    }

    pub fn close(mut self, err: ServeError) -> Result<(), ServeError> {
        self.error = Some(err);
        Ok(())
    }
}

impl ops::Deref for Announced {
    type Target = AnnounceInfo;

    fn deref(&self) -> &AnnounceInfo {
        &self.info
    }
}

impl Drop for Announced {
    fn drop(&mut self) {
        let err = self.error.clone().unwrap_or(ServeError::Done);

        // TODO SLG - ServeError's do not align with draft-13 Announce error codes (section 8.25)
        if self.ok {
            self.session.send_message(message::PublishNamespaceCancel {
                track_namespace: self.namespace.clone(),
                error_code: err.code(),
                reason_phrase: ReasonPhrase(err.to_string()),
            });
        } else {
            self.session.send_message(message::PublishNamespaceError {
                id: self.info.request_id,
                error_code: err.code(),
                reason_phrase: ReasonPhrase(err.to_string()),
            });
        }
    }
}

pub(super) struct AnnouncedRecv {
    _state: State<AnnouncedState>,
}

impl AnnouncedRecv {
    pub fn recv_unannounce(self) -> Result<(), ServeError> {
        // Will cause the state to be dropped
        Ok(())
    }
}