From 9aa53aa3aa49447d475d35db37f4fb1dd6b6da58 Mon Sep 17 00:00:00 2001
From: Shivaram Lingamneni <slingamn@cs.stanford.edu>
Date: Fri, 26 Jun 2020 18:02:22 -0400
Subject: [PATCH 1/4] update lastSeen on reattach

---
 irc/getters.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/irc/getters.go b/irc/getters.go
index f74e5f7c..1ba2c97c 100644
--- a/irc/getters.go
+++ b/irc/getters.go
@@ -106,6 +106,7 @@ func (client *Client) AddSession(session *Session) (success bool, numSessions in
 	newSessions[len(newSessions)-1] = session
 	if client.accountSettings.AutoreplayMissed || session.deviceID != "" {
 		lastSeen = client.lastSeen[session.deviceID]
+		client.setLastSeen(time.Now().UTC(), session.deviceID)
 	}
 	client.sessions = newSessions
 	if client.autoAway {

From e22adf47ca1826b46a4ae8cc7424a96f9cd7c27f Mon Sep 17 00:00:00 2001
From: Shivaram Lingamneni <slingamn@cs.stanford.edu>
Date: Fri, 26 Jun 2020 18:03:39 -0400
Subject: [PATCH 2/4] increase write interval for lastSeen

---
 irc/client.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/irc/client.go b/irc/client.go
index 2aae8dca..b9ba587d 100644
--- a/irc/client.go
+++ b/irc/client.go
@@ -34,7 +34,7 @@ const (
 	maxDeviceIDsPerClient = 64
 	// controls how often often we write an autoreplay-missed client's
 	// deviceid->lastseentime mapping to the database
-	lastSeenWriteInterval = time.Minute * 10
+	lastSeenWriteInterval = time.Hour
 )
 
 // ResumeDetails is a place to stash data at various stages of

From a38d375bda3848292360dacfe230adfa907f20e4 Mon Sep 17 00:00:00 2001
From: Shivaram Lingamneni <slingamn@cs.stanford.edu>
Date: Fri, 26 Jun 2020 18:23:33 -0400
Subject: [PATCH 3/4] delete always-on modes on unregistration

---
 irc/accounts.go | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/irc/accounts.go b/irc/accounts.go
index f5ceb757..40a40022 100644
--- a/irc/accounts.go
+++ b/irc/accounts.go
@@ -1245,6 +1245,7 @@ func (am *AccountManager) Unregister(account string, erase bool) error {
 	joinedChannelsKey := fmt.Sprintf(keyAccountJoinedChannels, casefoldedAccount)
 	lastSeenKey := fmt.Sprintf(keyAccountLastSeen, casefoldedAccount)
 	unregisteredKey := fmt.Sprintf(keyAccountUnregistered, casefoldedAccount)
+	modesKey := fmt.Sprintf(keyAccountModes, casefoldedAccount)
 
 	var clients []*Client
 
@@ -1299,6 +1300,7 @@ func (am *AccountManager) Unregister(account string, erase bool) error {
 		tx.Delete(channelsKey)
 		tx.Delete(joinedChannelsKey)
 		tx.Delete(lastSeenKey)
+		tx.Delete(modesKey)
 
 		_, err := tx.Delete(vhostQueueKey)
 		am.decrementVHostQueueCount(casefoldedAccount, err)

From 0f04acaa40f6f0362e36495135e3326f38d07b6c Mon Sep 17 00:00:00 2001
From: Shivaram Lingamneni <slingamn@cs.stanford.edu>
Date: Mon, 29 Jun 2020 00:30:27 -0400
Subject: [PATCH 4/4] persist last seen on shutdown

---
 irc/client.go | 24 +++++++++++++++++++++---
 irc/server.go |  3 +++
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/irc/client.go b/irc/client.go
index b9ba587d..bc36a41c 100644
--- a/irc/client.go
+++ b/irc/client.go
@@ -1724,7 +1724,7 @@ func (client *Client) wakeWriter() {
 
 func (client *Client) writeLoop() {
 	for {
-		client.performWrite()
+		client.performWrite(0)
 		client.writerSemaphore.Release()
 
 		client.stateMutex.RLock()
@@ -1737,9 +1737,9 @@ func (client *Client) writeLoop() {
 	}
 }
 
-func (client *Client) performWrite() {
+func (client *Client) performWrite(additionalDirtyBits uint) {
 	client.stateMutex.Lock()
-	dirtyBits := client.dirtyBits
+	dirtyBits := client.dirtyBits | additionalDirtyBits
 	client.dirtyBits = 0
 	account := client.account
 	client.stateMutex.Unlock()
@@ -1775,3 +1775,21 @@ func (client *Client) performWrite() {
 		client.server.accounts.saveModes(account, uModes)
 	}
 }
+
+// Blocking store; see Channel.Store and Socket.BlockingWrite
+func (client *Client) Store(dirtyBits uint) (err error) {
+	defer func() {
+		client.stateMutex.Lock()
+		isDirty := client.dirtyBits != 0
+		client.stateMutex.Unlock()
+
+		if isDirty {
+			client.wakeWriter()
+		}
+	}()
+
+	client.writerSemaphore.Acquire()
+	defer client.writerSemaphore.Release()
+	client.performWrite(dirtyBits)
+	return nil
+}
diff --git a/irc/server.go b/irc/server.go
index 98725553..8a5fbfb8 100644
--- a/irc/server.go
+++ b/irc/server.go
@@ -116,6 +116,9 @@ func (server *Server) Shutdown() {
 	//TODO(dan): Make sure we disallow new nicks
 	for _, client := range server.clients.AllClients() {
 		client.Notice("Server is shutting down")
+		if client.AlwaysOn() {
+			client.Store(IncludeLastSeen)
+		}
 	}
 
 	if err := server.store.Close(); err != nil {