package jwt

import (
	"context"
	"git.diulo.com/mogfee/kit/errors"
	"git.diulo.com/mogfee/kit/middleware"
	"git.diulo.com/mogfee/kit/transport"
)

const (
	permissionNoCheck = "none"
)

type userIdKey struct{}
type authKey struct {
}

type ParseFunc func(ctx context.Context, key string, tokenStr string) (*UserInfo, error)
type JwtOption func(o *options)

func WithJwtKey(jwtKey string) JwtOption {
	return func(o *options) {
		o.jwtKey = jwtKey
	}
}

func WithValidate(validate func(authKey string) error) JwtOption {
	return func(o *options) {
		o.validate = validate
	}
}

func WithValidatePermission(validatePermission func(permissions []string, key string) bool) JwtOption {
	return func(o *options) {
		o.validatePermission = validatePermission
	}
}

func WithParseFunc(parseFunc ParseFunc) JwtOption {
	return func(o *options) {
		o.parseFunc = parseFunc
	}
}

type options struct {
	jwtKey             string
	validate           func(authKey string) error
	validatePermission func(validatePermission []string, key string) bool
	parseFunc          ParseFunc
}

func JWT(opts ...JwtOption) middleware.Middleware {
	var cfg = &options{
		jwtKey:             "JssLx22bjQwnyqby",
		validatePermission: InSlice,
		parseFunc:          Parse,
	}
	for _, o := range opts {
		o(cfg)
	}

	return func(handler middleware.Handler) middleware.Handler {
		return func(ctx context.Context, a any) (any, error) {
			permission := FromAuthKeyContext(ctx)

			if permission == permissionNoCheck {
				return handler(ctx, a)
			}

			var tokenStr string
			if tr, ok := transport.FromServerContext(ctx); ok {
				tokenStr = tr.RequestHeader().Get("token")
			}
			userInfo, err := cfg.parseFunc(ctx, cfg.jwtKey, tokenStr)
			if err != nil {
				return nil, err
			}
			if permission != "" {
				if !cfg.validatePermission(userInfo.Permissions, permission) {
					return nil, errors.Unauthorized("TOKEN_PERMISSION_BAD", "")
				}
			}
			if cfg.validate != nil {
				if err = cfg.validate(userInfo.UniqueId); err != nil {
					return nil, err
				}
			}
			ctx = SetUserContext(ctx, userInfo)
			return handler(ctx, a)
		}
	}
}
func InSlice(validatePermission []string, key string) bool {
	for _, e := range validatePermission {
		if e == key {
			return true
		}
	}
	return false
}
func SetUserContext(ctx context.Context, user *UserInfo) context.Context {
	return context.WithValue(ctx, userIdKey{}, user)
}
func FromUserContext(ctx context.Context) (user *UserInfo, ok bool) {
	user, ok = ctx.Value(userIdKey{}).(*UserInfo)
	return
}

func SetAuthKeyContext(ctx context.Context, key string) context.Context {
	return context.WithValue(ctx, authKey{}, key)
}
func FromAuthKeyContext(ctx context.Context) string {
	v := ctx.Value(authKey{})
	if v == nil {
		return ""
	}
	return v.(string)
}