Cleaned up some validation code, stricter validation

internal/notif/config.go

@@ -0,0 +1,54 @@
+package notif
+
+import (
+	E "github.com/yusing/go-proxy/internal/error"
+	"github.com/yusing/go-proxy/internal/utils"
+)
+
+type NotificationConfig struct {
+	ProviderName string   `json:"provider"`
+	Provider     Provider `json:"-"`
+}
+
+var (
+	ErrMissingNotifProvider     = E.New("missing notification provider")
+	ErrInvalidNotifProviderType = E.New("invalid notification provider type")
+	ErrUnknownNotifProvider     = E.New("unknown notification provider")
+)
+
+// UnmarshalMap implements MapUnmarshaler.
+func (cfg *NotificationConfig) UnmarshalMap(m map[string]any) (err E.Error) {
+	// extract provider name
+	providerName := m["provider"]
+	switch providerName := providerName.(type) {
+	case string:
+		cfg.ProviderName = providerName
+	default:
+		return ErrInvalidNotifProviderType
+	}
+	delete(m, "provider")
+
+	if cfg.ProviderName == "" {
+		return ErrMissingNotifProvider
+	}
+
+	// validate provider name and initialize provider
+	switch cfg.ProviderName {
+	case ProviderWebhook:
+		cfg.Provider = &Webhook{}
+	case ProviderGotify:
+		cfg.Provider = &GotifyClient{}
+	default:
+		return ErrUnknownNotifProvider.
+			Subject(cfg.ProviderName).
+			Withf("expect %s or %s", ProviderWebhook, ProviderGotify)
+	}
+
+	// unmarshal provider config
+	if err := utils.Deserialize(m, cfg.Provider); err != nil {
+		return err
+	}
+
+	// validate provider
+	return cfg.Provider.Validate()
+}