codeword/internal/utils/middleware/authenticator.go

package middleware

import (
	"codeword/internal/models"
	"fmt"
	"strings"

	"github.com/gofiber/fiber/v2"
)

const (
	prefix = "Bearer "
)

func NewAuthenticator(jwtUtil *JWT) func(*fiber.Ctx) error {
	return func(c *fiber.Ctx) error {
		if jwtUtil == nil {
			return fmt.Errorf("jwt util is nil")
		}

		if err := authenticate(c, jwtUtil); err != nil {
			return fmt.Errorf("authentication error:%d", err)
		}

		return c.Next()
	}
}

func authenticate(c *fiber.Ctx, jwtUtil *JWT) error {
	authHeader := c.Get("Authorization")
	if authHeader == "" || !strings.HasPrefix(authHeader, prefix) {
		return fmt.Errorf("failed to parse jws from request header: %s", authHeader)
	}

	jws := strings.TrimPrefix(authHeader, prefix)

	userID, validateErr := jwtUtil.Validate(jws)
	if validateErr != nil {
		return validateErr
	}

	c.Locals(models.AuthJWTDecodedUserIDKey, userID)
	c.Locals(models.AuthJWTDecodedAccessTokenKey, jws)

	return nil
}

func ExtractUserID(c *fiber.Ctx) string {
	userID := c.Context().UserValue(models.AuthJWTDecodedUserIDKey).(string)
	return userID
}