refactor: support i18n

internal/pkg/i18nx/middleware.go

@@ -0,0 +1,86 @@
+package i18nx
+
+import (
+	"net/http"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+	"golang.org/x/text/language"
+)
+
+const (
+	LocaleZhCN = "zh-CN"
+	LocaleEnUS = "en-US"
+)
+
+var supportedLocales = map[string]string{
+	"zh":      LocaleZhCN,
+	"zh-cn":   LocaleZhCN,
+	"zh_cn":   LocaleZhCN,
+	"zh-hans": LocaleZhCN,
+	"en":      LocaleEnUS,
+	"en-us":   LocaleEnUS,
+	"en_us":   LocaleEnUS,
+}
+
+func NormalizeLocale(value string) string {
+	key := strings.ToLower(strings.TrimSpace(value))
+	if key == "" {
+		return LocaleZhCN
+	}
+	if locale, ok := supportedLocales[key]; ok {
+		return locale
+	}
+	return LocaleZhCN
+}
+
+func ResolveRequestLocale(req *http.Request) string {
+	if req == nil {
+		return LocaleZhCN
+	}
+	if locale := normalizeSupportedLocale(req.Header.Get("X-Locale")); locale != "" {
+		return locale
+	}
+	if locale := resolveAcceptLanguage(req.Header.Get("Accept-Language")); locale != "" {
+		return locale
+	}
+	if locale := normalizeSupportedLocale(req.URL.Query().Get("locale")); locale != "" {
+		return locale
+	}
+	return LocaleZhCN
+}
+
+func Middleware() gin.HandlerFunc {
+	return func(ctx *gin.Context) {
+		SetLocale(ctx, ResolveRequestLocale(ctx.Request))
+		ctx.Next()
+	}
+}
+
+func normalizeSupportedLocale(value string) string {
+	key := strings.ToLower(strings.TrimSpace(value))
+	if key == "" {
+		return ""
+	}
+	if locale, ok := supportedLocales[key]; ok {
+		return locale
+	}
+	return ""
+}
+
+func resolveAcceptLanguage(value string) string {
+	tags, _, err := language.ParseAcceptLanguage(value)
+	if err != nil {
+		return ""
+	}
+	for _, tag := range tags {
+		if locale := normalizeSupportedLocale(tag.String()); locale != "" {
+			return locale
+		}
+		base, _ := tag.Base()
+		if locale := normalizeSupportedLocale(base.String()); locale != "" {
+			return locale
+		}
+	}
+	return ""
+}