package auth

import (
	"errors"
	"strings"

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

const UserIDKey = "user_id"

func Middleware(svc *Service) fiber.Handler {
	return func(c *fiber.Ctx) error {
		h := c.Get("Authorization")
		if h == "" {
			return c.Status(fiber.StatusUnauthorized).JSON(fiber.Map{"error": "missing Authorization header"})
		}
		parts := strings.SplitN(h, " ", 2)
		if len(parts) != 2 || strings.ToLower(parts[0]) != "bearer" {
			return c.Status(fiber.StatusUnauthorized).JSON(fiber.Map{"error": "invalid Authorization header"})
		}
		claims, err := svc.Parse(c.UserContext(), parts[1])
		if err != nil {
			return c.Status(fiber.StatusUnauthorized).JSON(fiber.Map{"error": "invalid token"})
		}
		c.Locals(UserIDKey, claims.UserID)
		return c.Next()
	}
}

func UserID(c *fiber.Ctx) (string, error) {
	v := c.Locals(UserIDKey)
	if v == nil {
		return "", errors.New("no user in context")
	}
	if id, ok := v.(interface{ String() string }); ok {
		return id.String(), nil
	}
	return "", errors.New("invalid user id type")
}