feat(discord): keep threads alive by auto-unarchiving on ThreadUpdate

discord/commands/handler.go

@@ -28,6 +28,7 @@ func InitializeBot() {
 	service.Discord.AddHandler(OnGuildMemberUpdate)
 	service.Discord.AddHandler(OnGuildMemberRemove)
 	service.Discord.AddHandler(OnUserUpdate)
+	service.Discord.AddHandler(OnThreadUpdate)
 	service.Discord.Identify.Intents = discordgo.MakeIntent(discordgo.IntentsAll)
 	err := service.Discord.Open()
 	if err != nil {
@@ -166,6 +167,24 @@ func OnUserUpdate(s *discordgo.Session, u *discordgo.UserUpdate) {
 	service.SyncDiscordUserAvatar(u.ID, member.AvatarURL("256"))
 }
 
+// OnThreadUpdate keeps guild threads alive indefinitely. Discord doesn't
+// allow disabling thread auto-archival (7-day window at most), so when a
+// thread flips to archived we immediately flip it back. Unarchiving emits
+// another ThreadUpdate with Archived=false, which falls through the guard
+// below — no loop. Locked threads are left alone: locking is an explicit
+// moderator "this thread is closed" signal, and force-unarchiving those
+// would fight moderation.
+func OnThreadUpdate(s *discordgo.Session, t *discordgo.ThreadUpdate) {
+	if t.GuildID != config.DiscordGuild {
+		return
+	}
+	if t.ThreadMetadata == nil || !t.ThreadMetadata.Archived || t.ThreadMetadata.Locked {
+		return
+	}
+	logger.SugarLogger.Infof("ThreadUpdate: thread %s (%s) was archived, keeping alive", t.ID, t.Name)
+	service.KeepThreadAlive(t.Channel)
+}
+
 func diffRoles(before, after []string) (added, removed []string) {
 	beforeSet := make(map[string]struct{}, len(before))
 	for _, r := range before {

discord/service/thread_keepalive.go

@@ -0,0 +1,24 @@
+package service
+
+import (
+	"github.com/bwmarrin/discordgo"
+	"github.com/gaucho-racing/sentinel/discord/pkg/logger"
+)
+
+// KeepThreadAlive unarchives a thread that Discord just auto-archived and
+// bumps its auto-archive window to the maximum (7 days) so the gateway only
+// re-archives it weekly instead of on the channel's default window. The
+// unarchive is silent — no message is posted and members aren't notified.
+// Requires the bot to have MANAGE_THREADS in the guild.
+func KeepThreadAlive(thread *discordgo.Channel) {
+	archived := false
+	_, err := Discord.ChannelEdit(thread.ID, &discordgo.ChannelEdit{
+		Archived:            &archived,
+		AutoArchiveDuration: 10080,
+	})
+	if err != nil {
+		logger.SugarLogger.Errorf("thread keepalive: failed to unarchive thread %s (%s): %v", thread.ID, thread.Name, err)
+		return
+	}
+	logger.SugarLogger.Infof("thread keepalive: unarchived thread %s (%s)", thread.ID, thread.Name)
+}