✨ add i18n support

common/i18n/rpc_interceptor.go

@@ -0,0 +1,74 @@
+package i18n
+
+import (
+	"context"
+	"log"
+
+	i18n2 "github.com/nicksnyder/go-i18n/v2/i18n"
+	"golang.org/x/text/language"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/metadata"
+)
+
+var rpcInterceptorDebug = false
+
+func WithRpcInterceptorDebug(debug bool) {
+	rpcInterceptorDebug = debug
+}
+
+type I18nGrpcInterceptor struct {
+	supportTags       []language.Tag
+	localizationFiles []string
+}
+
+func NewI18nGrpcInterceptor(supportTags []language.Tag, localizationFiles []string) *I18nGrpcInterceptor {
+	if len(supportTags) == 0 {
+		panic("supportTags can not be empty")
+	}
+	return &I18nGrpcInterceptor{
+		supportTags:       supportTags,
+		localizationFiles: localizationFiles,
+	}
+}
+
+func (i *I18nGrpcInterceptor) Interceptor(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
+	ctx, err = i.saveLocalize(ctx)
+	if err != nil {
+		return nil, err
+	}
+	return handler(ctx, req)
+}
+
+func (i *I18nGrpcInterceptor) saveLocalize(ctx context.Context) (context.Context, error) {
+	respHeader, ok := metadata.FromIncomingContext(ctx)
+	// lang := "en-US" //language.English
+	langTag := i.supportTags[0]
+	lang := langTag.String()
+	if ok {
+		langs := respHeader.Get(defaultLangHeaderKey)
+		if len(langs) == 0 {
+			// return nil, status.Error(codes.Code(defaultErrCode), "can not correct get language")
+			if rpcInterceptorDebug {
+				log.Printf("can not correct get language")
+			}
+		} else {
+			lang = langs[0]
+			langTag = MatchCurrentLanguageTag(lang, i.supportTags)
+		}
+	} else {
+		if rpcInterceptorDebug {
+			log.Printf("can not correct get metadata1")
+		}
+		// return nil, status.Error(codes.Code(defaultErrCode), "can not correct get metadata1")
+	}
+
+	// lang := langs[0]
+	// langTag := MatchCurrentLanguageTag(lang, i.supportTags)
+	bundle := NewBundle(langTag, i.localizationFiles...)
+	localizer := i18n2.NewLocalizer(bundle, lang)
+	ctx = setLocalizer(ctx, localizer)
+
+	// Append the language metadata to the outgoing context
+	ctx = metadata.AppendToOutgoingContext(ctx, defaultLangHeaderKey, lang)
+	return ctx, nil
+}