threading: add backend capabilities to workers

This patch provides a method to report backend capabilities to the UI.
The intial capabilities included in the report are Sort and Thread.
Having these available to the UI enables the client to better handle
server side threading.

Signed-off-by: Koni Marti <koni.marti@gmail.com>
Signed-off-by: Tim Culverhouse <tim@timculverhouse.com>
Acked-by: Robin Jarry <robin@jarry.cc>

5 files changed, 34 insertions, 0 deletions

diff --git a/models/models.go b/models/models.go
index 96683f2..e7325d2 100644
--- a/models/models.go
+++ b/models/models.go
@@ -51,6 +51,15 @@ type DirectoryInfo struct {
 
 	// set to true if the value counts are accurate
 	AccurateCounts bool
+
+	// Caps contains the backend capabilities
+	Caps *Capabilities
+}
+
+// Capabilities provides the backend capabilities
+type Capabilities struct {
+	Sort   bool
+	Thread bool
 }
 
 // A MessageInfo holds information about the structure of a message
diff --git a/worker/imap/checkmail.go b/worker/imap/checkmail.go
index d9dcfd3..57af3af 100644
--- a/worker/imap/checkmail.go
+++ b/worker/imap/checkmail.go
@@ -31,6 +31,7 @@ func (w *IMAPWorker) handleCheckMailMessage(msg *types.CheckMail) {
 					Exists: int(status.Messages),
 					Recent: int(status.Recent),
 					Unseen: int(status.Unseen),
+					Caps:   w.caps,
 				},
 				SkipSort: true,
 			}, nil)
diff --git a/worker/imap/worker.go b/worker/imap/worker.go
index 7debd88..3ed646d 100644
--- a/worker/imap/worker.go
+++ b/worker/imap/worker.go
@@ -66,6 +66,8 @@ type IMAPWorker struct {
 	idler    *idler
 	observer *observer
 	cache    *leveldb.DB
+
+	caps *models.Capabilities
 }
 
 func NewIMAPWorker(worker *types.Worker) (types.Backend, error) {
@@ -75,6 +77,7 @@ func NewIMAPWorker(worker *types.Worker) (types.Backend, error) {
 		selected: &imap.MailboxStatus{},
 		idler:    newIdler(imapConfig{}, worker),
 		observer: newObserver(imapConfig{}, worker),
+		caps:     &models.Capabilities{},
 	}, nil
 }
 
@@ -83,6 +86,16 @@ func (w *IMAPWorker) newClient(c *client.Client) {
 	w.client = &imapClient{c, sortthread.NewThreadClient(c), sortthread.NewSortClient(c)}
 	w.idler.SetClient(w.client)
 	w.observer.SetClient(w.client)
+	sort, err := w.client.sort.SupportSort()
+	if err == nil && sort {
+		w.caps.Sort = true
+		w.worker.Logger.Println("Server Capability found: Sort")
+	}
+	thread, err := w.client.thread.SupportThread()
+	if err == nil && thread {
+		w.caps.Thread = true
+		w.worker.Logger.Println("Server Capability found: Thread")
+	}
 }
 
 func (w *IMAPWorker) handleMessage(msg types.WorkerMessage) error {
@@ -226,6 +239,7 @@ func (w *IMAPWorker) handleImapUpdate(update client.Update) {
 				Exists: int(status.Messages),
 				Recent: int(status.Recent),
 				Unseen: int(status.Unseen),
+				Caps:   w.caps,
 			},
 		}, nil)
 	case *client.MessageUpdate:
diff --git a/worker/maildir/worker.go b/worker/maildir/worker.go
index cf2970e..0862838 100644
--- a/worker/maildir/worker.go
+++ b/worker/maildir/worker.go
@@ -186,6 +186,11 @@ func (w *Worker) getDirectoryInfo(name string) *models.DirectoryInfo {
 		Unseen: 0,
 
 		AccurateCounts: false,
+
+		Caps: &models.Capabilities{
+			Sort:   true,
+			Thread: false,
+		},
 	}
 
 	dir := w.c.Dir(name)
diff --git a/worker/notmuch/worker.go b/worker/notmuch/worker.go
index 51e8298..35e6840 100644
--- a/worker/notmuch/worker.go
+++ b/worker/notmuch/worker.go
@@ -228,6 +228,11 @@ func (w *worker) gatherDirectoryInfo(name string, query string) (
 			// total unread
 			Unseen:         count.Unread,
 			AccurateCounts: true,
+
+			Caps: &models.Capabilities{
+				Sort:   true,
+				Thread: true,
+			},
 		},
 	}
 	return info, nil