package mildware

import (
	"net/http"
	"strconv"
	"strings"

	"gen2d/internal/logger"
	"gen2d/internal/model"

	"github.com/gin-gonic/gin"
	"github.com/golang-jwt/jwt/v5"
)

// AuthMiddleware 返回 JWT 认证中间件，校验 Bearer token 并注入 userID 到上下文。
func AuthMiddleware(jwtSecret string) gin.HandlerFunc {
	return func(c *gin.Context) {
		authHeader := c.GetHeader("Authorization")
		if authHeader == "" {
			logger.FromCtx(c.Request.Context()).Warn("auth failed: no token")
			c.AbortWithStatusJSON(http.StatusUnauthorized, model.Fail(http.StatusUnauthorized, "未提供认证令牌"))
			return
		}

		tokenString := strings.TrimPrefix(authHeader, "Bearer ")
		if tokenString == authHeader {
			logger.FromCtx(c.Request.Context()).Warn("auth failed: invalid format")
			c.AbortWithStatusJSON(http.StatusUnauthorized, model.Fail(http.StatusUnauthorized, "认证格式错误，需为 Bearer <token>"))
			return
		}

		token, err := jwt.Parse(tokenString, func(token *jwt.Token) (interface{}, error) {
			return []byte(jwtSecret), nil
		})
		if err != nil || !token.Valid {
			logger.FromCtx(c.Request.Context()).Warn("auth failed: invalid token", "error", err)
			c.AbortWithStatusJSON(http.StatusUnauthorized, model.Fail(http.StatusUnauthorized, "令牌无效或已过期"))
			return
		}

		claims, ok := token.Claims.(jwt.MapClaims)
		if !ok {
			logger.FromCtx(c.Request.Context()).Warn("auth failed: parse claims")
			c.AbortWithStatusJSON(http.StatusUnauthorized, model.Fail(http.StatusUnauthorized, "令牌解析失败"))
			return
		}

		if sub, ok := claims["sub"]; ok {
			var userID uint
			switch v := sub.(type) {
			case float64:
				userID = uint(v)
			case int:
				userID = uint(v)
			case int64:
				userID = uint(v)
			case uint:
				userID = v
			case string:
				num, err := strconv.ParseUint(v, 10, 64)
				if err == nil {
					userID = uint(num)
				}
			}
			c.Set("userID", userID)
		}

		c.Next()
	}
}