First commit

backend/internal/middleware/middleware.go

@@ -0,0 +1,35 @@
+package middleware
+
+import "github.com/gin-gonic/gin"
+
+// ContextKey 定义上下文键类型
+type ContextKey string
+
+const (
+	// ContextKeyUser 用户上下文键
+	ContextKeyUser ContextKey = "user"
+	// ContextKeyApiKey API密钥上下文键
+	ContextKeyApiKey ContextKey = "api_key"
+	// ContextKeySubscription 订阅上下文键
+	ContextKeySubscription ContextKey = "subscription"
+)
+
+// ErrorResponse 标准错误响应结构
+type ErrorResponse struct {
+	Code    string `json:"code"`
+	Message string `json:"message"`
+}
+
+// NewErrorResponse 创建错误响应
+func NewErrorResponse(code, message string) ErrorResponse {
+	return ErrorResponse{
+		Code:    code,
+		Message: message,
+	}
+}
+
+// AbortWithError 中断请求并返回JSON错误
+func AbortWithError(c *gin.Context, statusCode int, code, message string) {
+	c.JSON(statusCode, NewErrorResponse(code, message))
+	c.Abort()
+}