Save last viewed at state and use for replaying logs (#361)

* Fixed logging in with personal access token

* Save last viewed at state and use for replaying logs

Per #245, we can't trust
that Mattermost has updated the last viewed for channel. Instead, we
save this locally and use that for replaying of logs. Useful for when
experiencing flaky network causing matterircd to reconnect.

* Fixed using defer in range loops

* Also make the map

mm-go-irckit/userbridge.go

@@ -23,6 +23,8 @@ type UserBridge struct {
 	Credentials        bridge.Credentials
 	br                 bridge.Bridger    //nolint:structcheck
 	inprogress         bool              //nolint:structcheck
+	lastViewedAt       map[string]int64  //nolint:structcheck
+	lastViewedAtMutex  sync.RWMutex      //nolint:structcheck
 	msgLast            map[string]string //nolint:structcheck
 	msgLastMutex       sync.RWMutex      //nolint:structcheck
 	msgMap             map[string]map[string]int
@@ -41,6 +43,7 @@ func NewUserBridge(c net.Conn, srv Server, cfg *viper.Viper) *User {
 
 	u.Srv = srv
 	u.v = cfg
+	u.lastViewedAt = make(map[string]int64)
 	u.msgLast = make(map[string]string)
 	u.msgMap = make(map[string]map[string]int)
 	u.msgCounter = make(map[string]int)
@@ -147,6 +150,9 @@ func (u *User) handleDirectMessageEvent(event *bridge.DirectMessageEvent) {
 	if !u.v.GetBool(u.br.Protocol() + ".disableautoview") {
 		u.updateLastViewed(event.ChannelID)
 	}
+	u.lastViewedAtMutex.Lock()
+	defer u.lastViewedAtMutex.Unlock()
+	u.lastViewedAt[event.ChannelID] = model.GetMillis()
 }
 
 func (u *User) handleChannelAddEvent(event *bridge.ChannelAddEvent) {
@@ -170,6 +176,9 @@ func (u *User) handleChannelAddEvent(event *bridge.ChannelAddEvent) {
 	if !u.v.GetBool(u.br.Protocol() + ".disableautoview") {
 		u.updateLastViewed(event.ChannelID)
 	}
+	u.lastViewedAtMutex.Lock()
+	defer u.lastViewedAtMutex.Unlock()
+	u.lastViewedAt[event.ChannelID] = model.GetMillis()
 }
 
 func (u *User) handleChannelRemoveEvent(event *bridge.ChannelRemoveEvent) {
@@ -275,6 +284,9 @@ func (u *User) handleChannelMessageEvent(event *bridge.ChannelMessageEvent) {
 	if !u.v.GetBool(u.br.Protocol() + ".disableautoview") {
 		u.updateLastViewed(event.ChannelID)
 	}
+	u.lastViewedAtMutex.Lock()
+	defer u.lastViewedAtMutex.Unlock()
+	u.lastViewedAt[event.ChannelID] = model.GetMillis()
 }
 
 func (u *User) handleFileEvent(event *bridge.FileEvent) {
@@ -536,6 +548,12 @@ func (u *User) addUserToChannelWorker(channels <-chan *bridge.ChannelInfo, throt
 		if since == 0 {
 			continue
 		}
+		// We used to stored last viewed at if present.
+		u.lastViewedAtMutex.RLock()
+		if lastViewedAt, ok := u.lastViewedAt[brchannel.ID]; ok {
+			since = lastViewedAt
+		}
+		u.lastViewedAtMutex.RUnlock()
 		// post everything to the channel you haven't seen yet
 		postlist := u.br.GetPostsSince(brchannel.ID, since)
 		if postlist == nil {
@@ -606,6 +624,9 @@ func (u *User) addUserToChannelWorker(channels <-chan *bridge.ChannelInfo, throt
 		if !u.v.GetBool(u.br.Protocol() + ".disableautoview") {
 			u.updateLastViewed(brchannel.ID)
 		}
+		u.lastViewedAtMutex.Lock()
+		u.lastViewedAt[brchannel.ID] = model.GetMillis()
+		u.lastViewedAtMutex.Unlock()
 	}
 }