refactor: Convert capitalization to TextVar flag

cmd/update-plex-ipv6-access-url/internal/config/config.go

@@ -23,7 +23,7 @@ type Config struct {
 	AddrPreference handler.AddrPreference
 	ConfigPath     string
 	Token          string
-	Capitalization string
+	Capitalization handler.IPv6URLCapitalization
 	Timeout        int
 }
 
@@ -38,7 +38,7 @@ func Init() *Config {
 	flag.TextVar(&cfg.AddrPreference, "use", handler.AddrPreferenceFirst, "Which IPv6 address(es) to use if multiple are found on the interface (first|last|all)")
 	flag.StringVar(&cfg.ConfigPath, "config", "", "Path to Plex config (Preferences.xml)")
 	flag.StringVar(&cfg.Token, "token", "", "Plex access token (X-Plex-Token) [required if 'config' flag is/cannot be provided]")
-	flag.StringVar(&cfg.Capitalization, "capitalization", "", "Capitalization to use for dashed IPv6 address in Plex custom access URL (upper|lower)")
+	flag.TextVar(&cfg.Capitalization, "capitalization", handler.IPv6URLCapitalizationLower, "Capitalization to use for dashed IPv6 address in Plex custom access URL (upper|lower)")
 	flag.IntVar(&cfg.Timeout, "timeout", 5, "Plex API request timeout (in seconds)")
 	flag.Parse()
 	return cfg

cmd/update-plex-ipv6-access-url/internal/handler/capitalization.go

@@ -0,0 +1,42 @@
+package handler
+
+import (
+	"fmt"
+)
+
+type IPv6URLCapitalization string
+
+const (
+	IPv6URLCapitalizationLower IPv6URLCapitalization = "lower"
+	IPv6URLCapitalizationUpper IPv6URLCapitalization = "upper"
+)
+
+//goland:noinspection GoMixedReceiverTypes
+func (c IPv6URLCapitalization) String() string {
+	return string(c)
+}
+
+//goland:noinspection GoMixedReceiverTypes
+func (c *IPv6URLCapitalization) UnmarshalText(text []byte) error {
+	if len(text) == 0 {
+		*c = ""
+		return nil
+	}
+
+	s := string(text)
+	switch s {
+	case string(IPv6URLCapitalizationLower):
+		*c = IPv6URLCapitalizationLower
+	case string(IPv6URLCapitalizationUpper):
+		*c = IPv6URLCapitalizationUpper
+	default:
+		return fmt.Errorf("invalid IPv6 URL capitalization: %s", s)
+	}
+
+	return nil
+}
+
+//goland:noinspection GoMixedReceiverTypes
+func (c IPv6URLCapitalization) MarshalText() (text []byte, err error) {
+	return []byte(c), nil
+}

cmd/update-plex-ipv6-access-url/internal/handler/handler.go

@@ -10,13 +10,6 @@ import (
 	"github.com/cetteup/update-plex-ipv6-access-url/internal/plex"
 )
 
-type IPv6URLCapitalization string
-
-const (
-	IPv6URLCapitalizationLower IPv6URLCapitalization = "lower"
-	IPv6URLCapitalizationUpper IPv6URLCapitalization = "upper"
-)
-
 type ApiClient interface {
 	GetIdentity() (plex.IdentityDTO, error)
 	GetResources() (plex.ResourcesDTO, error)

cmd/update-plex-ipv6-access-url/main.go

@@ -72,7 +72,7 @@ func main() {
 	remoteClient := plex.NewApiClient(plex.BaseURL, cfg.Token, cfg.Timeout)
 	h := handler.NewHandler(localClient, remoteClient)
 
-	selectedAddrs, err := h.SelectAddrs(interfaceAddrs, handler.AddrPreference(cfg.AddrPreference))
+	selectedAddrs, err := h.SelectAddrs(interfaceAddrs, cfg.AddrPreference)
 	if err != nil {
 		log.Fatal().
 			Err(err).
@@ -86,7 +86,7 @@ func main() {
 			Msg("Selected IPv6 addresses")
 	}
 
-	err = h.UpdateIPv6CustomAccessURLs(selectedAddrs, handler.IPv6URLCapitalization(cfg.Capitalization))
+	err = h.UpdateIPv6CustomAccessURLs(selectedAddrs, cfg.Capitalization)
 	if err != nil {
 		log.Fatal().
 			Err(err).