feat: initial official i18n support for backend

middleware/language.go

@@ -0,0 +1,25 @@
+package middleware
+
+import (
+	"strings"
+
+	"github.com/gin-gonic/gin"
+
+	"github.com/songquanpeng/one-api/common/i18n"
+)
+
+func Language() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		lang := c.GetHeader("Accept-Language")
+		if lang == "" {
+			lang = "en"
+		}
+		if strings.HasPrefix(strings.ToLower(lang), "zh") {
+			lang = "zh-CN"
+		} else {
+			lang = "en"
+		}
+		c.Set(i18n.ContextKey, lang)
+		c.Next()
+	}
+}