Add a generate-registration command

config/registration.go

@@ -0,0 +1,33 @@
+package config
+
+import (
+	"fmt"
+	"regexp"
+
+	as "maunium.net/go/mautrix/appservice"
+)
+
+func (cfg *Config) CopyToRegistration(registration *as.Registration) error {
+	registration.ID = cfg.Appservice.ID
+	registration.URL = cfg.Appservice.Address
+
+	falseVal := false
+	registration.RateLimited = &falseVal
+
+	registration.SenderLocalpart = cfg.Appservice.Bot.Username
+
+	pattern := fmt.Sprintf(
+		"^@%s:%s$",
+		cfg.Bridge.FormatUsername("[0-9]+"),
+		cfg.Homeserver.Domain,
+	)
+
+	userIDRegex, err := regexp.Compile(pattern)
+	if err != nil {
+		return err
+	}
+
+	registration.Namespaces.RegisterUserIDs(userIDRegex, true)
+
+	return nil
+}