def uploadshare(uploadId, shareUserId):
    r = Response(mimetype="application/json")
    r.headers["Content-Type"] = "text/json; charset=utf-8"

    token = request.headers['Authorization'].split(' ')[1]
    data = jwt.decode(token.encode('UTF-8'), 'SECRET', algorithm='HS256')

    upload = get_db().uploads.find_one({'_id': ObjectId(uploadId), 'status': 'done', 'ownerid': data['sub']})

    if upload is None:
        r.response = json.dumps({'error': 'upload id not found'})
        r.status_code = HTTPStatus.NOT_FOUND
        return r

    u = get_db().users.find_one({"name": shareUserId})
    if u is None:
        r.response = json.dumps({'error': 'user not found'})
        r.status_code = HTTPStatus.NOT_FOUND
        return r

    if shareUserId in upload['users']:
        r.response = json.dumps({'status': 'already shared'})
        r.status_code = HTTPStatus.OK
        return r

    get_db().uploads.update_one({'_id': ObjectId(uploadId)}, {'$push': {'users': shareUserId}})
    r.response = json.dumps({'status': 'share success'})
    r.status_code = HTTPStatus.OK
    return r