1 files changed, 61 insertions, 19 deletions

diff --git a/src/imap/flow.rs b/src/imap/flow.rs
index 95810c1..6ddd092 100644
--- a/src/imap/flow.rs
+++ b/src/imap/flow.rs
@@ -1,9 +1,11 @@
 use std::error::Error as StdError;
 use std::fmt;
 use std::sync::Arc;
+use tokio::sync::Notify;
 
 use crate::imap::mailbox_view::MailboxView;
 use crate::mail::user::User;
+use imap_codec::imap_types::core::Tag;
 
 #[derive(Debug)]
 pub enum Error {
@@ -19,44 +21,84 @@ impl StdError for Error {}
 pub enum State {
     NotAuthenticated,
     Authenticated(Arc<User>),
-    Selected(Arc<User>, MailboxView),
-    // Examined is like Selected, but indicates that the mailbox is read-only
-    Examined(Arc<User>, MailboxView),
+    Selected(Arc<User>, MailboxView, MailboxPerm),
+    Idle(
+        Arc<User>,
+        MailboxView,
+        MailboxPerm,
+        Tag<'static>,
+        Arc<Notify>,
+    ),
     Logout,
 }
+impl fmt::Display for State {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        use State::*;
+        match self {
+            NotAuthenticated => write!(f, "NotAuthenticated"),
+            Authenticated(..) => write!(f, "Authenticated"),
+            Selected(..) => write!(f, "Selected"),
+            Idle(..) => write!(f, "Idle"),
+            Logout => write!(f, "Logout"),
+        }
+    }
+}
+
+#[derive(Clone)]
+pub enum MailboxPerm {
+    ReadOnly,
+    ReadWrite,
+}
 
 pub enum Transition {
     None,
     Authenticate(Arc<User>),
-    Examine(MailboxView),
-    Select(MailboxView),
+    Select(MailboxView, MailboxPerm),
+    Idle(Tag<'static>, Notify),
+    UnIdle,
     Unselect,
     Logout,
 }
+impl fmt::Display for Transition {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        use Transition::*;
+        match self {
+            None => write!(f, "None"),
+            Authenticate(..) => write!(f, "Authenticated"),
+            Select(..) => write!(f, "Selected"),
+            Idle(..) => write!(f, "Idle"),
+            UnIdle => write!(f, "UnIdle"),
+            Unselect => write!(f, "Unselect"),
+            Logout => write!(f, "Logout"),
+        }
+    }
+}
 
 // See RFC3501 section 3.
 // https://datatracker.ietf.org/doc/html/rfc3501#page-13
 impl State {
     pub fn apply(&mut self, tr: Transition) -> Result<(), Error> {
-        let new_state = match (&self, tr) {
-            (_s, Transition::None) => return Ok(()),
+        tracing::debug!(state=%self, transition=%tr, "try change state");
+
+        let new_state = match (std::mem::replace(self, State::Logout), tr) {
+            (s, Transition::None) => s,
             (State::NotAuthenticated, Transition::Authenticate(u)) => State::Authenticated(u),
-            (
-                State::Authenticated(u) | State::Selected(u, _) | State::Examined(u, _),
-                Transition::Select(m),
-            ) => State::Selected(u.clone(), m),
-            (
-                State::Authenticated(u) | State::Selected(u, _) | State::Examined(u, _),
-                Transition::Examine(m),
-            ) => State::Examined(u.clone(), m),
-            (State::Selected(u, _) | State::Examined(u, _), Transition::Unselect) => {
-                State::Authenticated(u.clone())
+            (State::Authenticated(u) | State::Selected(u, _, _), Transition::Select(m, p)) => {
+                State::Selected(u, m, p)
             }
+            (State::Selected(u, _, _), Transition::Unselect) => State::Authenticated(u.clone()),
+            (State::Selected(u, m, p), Transition::Idle(t, s)) => {
+                State::Idle(u, m, p, t, Arc::new(s))
+            }
+            (State::Idle(u, m, p, _, _), Transition::UnIdle) => State::Selected(u, m, p),
             (_, Transition::Logout) => State::Logout,
-            _ => return Err(Error::ForbiddenTransition),
+            (s, t) => {
+                tracing::error!(state=%s, transition=%t, "forbidden transition");
+                return Err(Error::ForbiddenTransition);
+            }
         };
-
         *self = new_state;
+        tracing::debug!(state=%self, "transition succeeded");
 
         Ok(())
     }