package middleware

import (
	"net/http"
	"strings"

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

// TokenParser 解析 JWT token 的接口
type TokenParser interface {
	ParseToken(tokenStr string) (string, error)
}

// JWTAuth 管理后台 JWT 鉴权中间件
func JWTAuth(parser TokenParser) gin.HandlerFunc {
	return func(c *gin.Context) {
		authHeader := c.GetHeader("Authorization")
		if authHeader == "" {
			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{
				"code":    "401",
				"message": "未登录，请先登录",
			})
			return
		}

		parts := strings.SplitN(authHeader, " ", 2)
		if len(parts) != 2 || parts[0] != "Bearer" {
			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{
				"code":    "401",
				"message": "Token 格式错误",
			})
			return
		}

		username, err := parser.ParseToken(parts[1])
		if err != nil {
			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{
				"code":    "401",
				"message": "Token 无效或已过期",
			})
			return
		}

		c.Set("username", username)
		c.Next()
	}
}