package middleware

import (
	"net/http"
	"strings"

	"github.com/gin-gonic/gin"
	"gorm.io/gorm"

	"wx_service/internal/model"
)

const ContextCurrentUserKey = "currentUser"

func AuthMiddleware(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		token := extractToken(c.GetHeader("Authorization"))
		if token == "" {
			c.AbortWithStatusJSON(http.StatusUnauthorized, model.Error(http.StatusUnauthorized, "missing authorization header"))
			return
		}

		var user model.User
		if err := db.WithContext(c.Request.Context()).Where("session_key = ?", token).First(&user).Error; err != nil {
			if err == gorm.ErrRecordNotFound {
				c.AbortWithStatusJSON(http.StatusUnauthorized, model.Error(http.StatusUnauthorized, "invalid token"))
				return
			}
			c.AbortWithStatusJSON(http.StatusInternalServerError, model.Error(http.StatusInternalServerError, "load user failed"))
			return
		}

		c.Set(ContextCurrentUserKey, &user)
		c.Next()
	}
}

func extractToken(authHeader string) string {
	if authHeader == "" {
		return ""
	}
	parts := strings.SplitN(authHeader, " ", 2)
	if len(parts) != 2 {
		return ""
	}
	if !strings.EqualFold(parts[0], "Bearer") {
		return ""
	}
	return strings.TrimSpace(parts[1])
}