support !help, find clints change to end of string

main.go

@@ -56,6 +56,31 @@ func matrixrecv() error {
 	if err != nil {
 		return err
 	}
+	func() {
+		log.Printf("looking for help")
+		printed := false
+		for _, msg := range messages {
+			if !strings.HasPrefix(msg.Content, "!help") {
+				continue
+			}
+			if !printed {
+				key := fmt.Sprintf("help_%d", msg.Timestamp.Unix())
+				db := config.Get().DB()
+				if _, err := db.Get(key); err == storage.ErrNotFound {
+					log.Printf("sending help")
+					help := fmt.Sprintf("commands:\n\t!help\tprint this help\n\t!state nc NC nC Nc\tset states for self\n\t!available 2022-12-31\tset date self is available for work\n\nrun a command for someone else: `!state ga @caleb`")
+					if err := sender.Send(help); err != nil {
+						log.Printf("failed to send help: %v", err)
+					} else {
+						printed = true
+						if err := db.Set(key, []byte{'k'}); err != nil {
+							log.Printf("failed to mark help given @%s: %v", key, err)
+						}
+					}
+				}
+			}
+		}
+	}()
 	func() {
 		log.Printf("looking for states")
 		states := map[string]map[config.State]struct{}{}
@@ -98,10 +123,10 @@ func matrixrecv() error {
 }
 
 func setNewPauses(pauses map[string]time.Time) {
-	log.Printf("set new pauses: %+v", pauses)
 	if len(pauses) == 0 {
 		return
 	}
+	log.Printf("set new pauses: %+v", pauses)
 	conf := *config.Get()
 	changed := map[string]time.Time{}
 	for client, pause := range pauses {