package middleware

import (
	"backend/config"
	"backend/utils"
	"net/http"
	"strings"

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

// AuthMiddleware 校验访问令牌并将用户身份写入请求上下文。 // Logan.Li
func AuthMiddleware(cfg *config.Config) gin.HandlerFunc {
	return func(c *gin.Context) {
		authHeader := c.GetHeader("Authorization")
		if authHeader == "" {
			c.JSON(http.StatusUnauthorized, gin.H{
				"code":    401,
				"message": "未提供认证令牌",
				"data":    nil,
			})
			c.Abort()
			return
		}

		// 检查 Bearer 前缀 // Logan.Li
		parts := strings.SplitN(authHeader, " ", 2)
		if len(parts) != 2 || parts[0] != "Bearer" {
			c.JSON(http.StatusUnauthorized, gin.H{
				"code":    401,
				"message": "认证令牌格式错误",
				"data":    nil,
			})
			c.Abort()
			return
		}

		token := parts[1]
		claims, err := utils.ParseToken(token, cfg.JWTSecret)
		if err != nil {
			c.JSON(http.StatusUnauthorized, gin.H{
				"code":    401,
				"message": "无效的认证令牌",
				"data":    nil,
			})
			c.Abort()
			return
		}

		// 将用户身份写入上下文，供后续 handler 使用 // Logan.Li
		c.Set("user_id", claims.UserID)
		c.Set("username", claims.Username)
		c.Set("role", claims.Role)
		c.Next()
	}
}