package middleware

import (
	"crypto/subtle"
	"net/http"
	"strings"

	"github.com/gin-gonic/gin"
)

// RequireAPIKey 校验 Authorization: Bearer <api_key>（常数时间比较），不匹配返回 401。
func RequireAPIKey(key string) gin.HandlerFunc {
	return func(c *gin.Context) {
		token := strings.TrimSpace(strings.TrimPrefix(c.GetHeader("Authorization"), "Bearer "))
		if key == "" || subtle.ConstantTimeCompare([]byte(token), []byte(key)) != 1 {
			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "UNAUTHORIZED"})
			return
		}
		c.Next()
	}
}