From 6d3505a960076fa5b31d1c2a57ee4438a9e10646 Mon Sep 17 00:00:00 2001
From: Nick Krichevsky <nick@ollien.com>
Date: Thu, 12 May 2022 18:38:08 -0400
Subject: [PATCH] Clean up use of generics on Session

---
 src/fetch.rs      | 19 +++++--------------
 src/inbox.rs      | 15 ++++++---------
 src/inbox/idle.rs |  9 ++++-----
 src/lib.rs        | 18 ++++++++++--------
 4 files changed, 25 insertions(+), 36 deletions(-)

diff --git a/src/fetch.rs b/src/fetch.rs
index 301050e..aca4f08 100644
--- a/src/fetch.rs
+++ b/src/fetch.rs
@@ -1,27 +1,18 @@
 use std::error::Error;
-use std::{fmt::Debug, time::Duration};
-
-use async_imap::{
-    extensions::idle::{Handle, IdleResponse},
-    imap_proto::{MailboxDatum, Response},
-    Session,
-};
-use futures::{AsyncRead, AsyncWrite, StreamExt};
 
 use crate::inbox::SequenceNumber;
+use crate::IMAPSession;
+use futures::StreamExt;
 
 /// `fetch_email` will consume the current session and put it into an `Idle` state, until a new email is received
 ///
 /// # Errors
 /// If, for any reason, the email fails to be fetched, one of `async_imap` error's will be returned.
 #[allow(clippy::module_name_repetitions)]
-pub async fn fetch_email<T>(
-    session: &mut Session<T>,
+pub async fn fetch_email(
+    session: &mut IMAPSession,
     sequence_number: SequenceNumber,
-) -> Result<String, Box<dyn Error>>
-where
-    T: AsyncRead + AsyncWrite + Unpin + Debug + Send,
-{
+) -> Result<String, Box<dyn Error>> {
     let message = session
         .fetch(format!("{}", sequence_number.value()), "RFC822")
         .await?
diff --git a/src/inbox.rs b/src/inbox.rs
index eaf6455..c1eb1e5 100644
--- a/src/inbox.rs
+++ b/src/inbox.rs
@@ -4,12 +4,13 @@ use async_imap::{
     error::{Error as IMAPError, Result as IMAPResult},
     extensions::idle::Handle,
     imap_proto::{MailboxDatum, Response},
-    Session,
 };
 use futures::{AsyncRead, AsyncWrite};
 use thiserror::Error;
 use tokio::sync::broadcast::{self, error::SendError};
 
+use crate::{IMAPClient, IMAPSession, IMAPTransportStream};
+
 mod idle;
 
 #[derive(Clone, Copy, Debug)]
@@ -58,10 +59,7 @@ impl Watcher {
 
     /// Watch for the arrival of a single email. While the `Watcher` is watching, the caller must relinquish ownership
     /// of the `Session`, but it will be returned to it upon succesful completion of the
-    pub async fn watch_for_email<T>(&self, session: Session<T>) -> Result<Session<T>, WatchError>
-    where
-        T: AsyncRead + AsyncWrite + Unpin + Debug + Send,
-    {
+    pub async fn watch_for_email(&self, session: IMAPSession) -> Result<IMAPSession, WatchError> {
         let mut idle_handle = session.idle();
         let sequence_number = Self::idle_for_email(&mut idle_handle).await?;
         self.sender.send(sequence_number)?;
@@ -70,10 +68,9 @@ impl Watcher {
         Ok(reclaimed_session)
     }
 
-    async fn idle_for_email<T>(idle_handle: &mut Handle<T>) -> IMAPResult<SequenceNumber>
-    where
-        T: AsyncRead + AsyncWrite + Unpin + Debug + Send,
-    {
+    async fn idle_for_email(
+        idle_handle: &mut Handle<IMAPTransportStream>,
+    ) -> IMAPResult<SequenceNumber> {
         loop {
             idle_handle.init().await?;
             let idle_res = idle::wait_for_data(idle_handle).await;
diff --git a/src/inbox/idle.rs b/src/inbox/idle.rs
index 5d13aa5..59c9080 100644
--- a/src/inbox/idle.rs
+++ b/src/inbox/idle.rs
@@ -2,12 +2,14 @@ use std::{fmt::Debug, time::Duration};
 use thiserror::Error;
 
 use async_imap::{
-    error::{Error as IMAPError, Result as IMAPResult},
+    error::Error as IMAPError,
     extensions::idle::{Handle, IdleResponse},
     imap_proto::Response as IMAPResponse,
 };
 use futures::{AsyncRead, AsyncWrite};
 
+use crate::IMAPTransportStream;
+
 // 29 minutes, as per RFC2177 which specifies we should re-issue our idle every 29 minutes
 const WAIT_TIMEOUT: Duration = Duration::from_secs(29 * 60);
 
@@ -55,10 +57,7 @@ impl Data {
     }
 }
 
-pub async fn wait_for_data<T>(idle_handle: &mut Handle<T>) -> Result<Data, Error>
-where
-    T: AsyncRead + AsyncWrite + Unpin + Debug + Send,
-{
+pub async fn wait_for_data(idle_handle: &mut Handle<IMAPTransportStream>) -> Result<Data, Error> {
     println!("starting timeout wait...");
     let (idle_response_future, _stop) = idle_handle.wait_with_timeout(WAIT_TIMEOUT);
     let idle_response = idle_response_future.await?;
diff --git a/src/lib.rs b/src/lib.rs
index 337c2d5..c268085 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -7,8 +7,9 @@ extern crate log;
 
 use std::fmt::Debug;
 
-use async_imap::{self, Client, Session};
-use async_native_tls::TlsConnector;
+use async_imap;
+use async_native_tls::{TlsConnector, TlsStream};
+use async_std::net::TcpStream;
 pub use config::{Config, IMAP as IMAPConfig};
 use futures::{AsyncRead, AsyncWrite};
 
@@ -20,9 +21,12 @@ mod inbox;
 pub use fetch::fetch_email;
 pub use inbox::{SequenceNumber, Watcher};
 
-pub async fn setup_session(
-    cfg: &Config,
-) -> async_imap::error::Result<Session<impl AsyncRead + AsyncWrite + Unpin + Debug + Send>> {
+type IMAPTransportStream = TlsStream<TcpStream>;
+// TODO: Probably doesn't need to be pub
+type IMAPClient = async_imap::Client<IMAPTransportStream>;
+pub type IMAPSession = async_imap::Session<IMAPTransportStream>;
+
+pub async fn setup_session(cfg: &Config) -> async_imap::error::Result<IMAPSession> {
     let imap_cfg = cfg.imap();
     println!("Logging in...");
     let client = build_imap_client(imap_cfg).await?;
@@ -33,9 +37,7 @@ pub async fn setup_session(
         .map_err(|err| err.0)
 }
 
-async fn build_imap_client(
-    imap_cfg: &IMAPConfig,
-) -> async_imap::error::Result<Client<impl AsyncRead + AsyncWrite + Unpin + Debug>> {
+async fn build_imap_client(imap_cfg: &IMAPConfig) -> async_imap::error::Result<IMAPClient> {
     let tls_connector = TlsConnector::new();
     async_imap::connect(
         (imap_cfg.domain(), imap_cfg.port()),