def load_user(data):
    """Load user from data dump.

    NOTE: This task takes into account the possible duplication of emails and
    usernames, hence it should be called synchronously.
    In such case of collision it will raise UserEmailExistsError or
    UserUsernameExistsError, if email or username are already existing in
    the database. Caller of this task should take care to to resolve those
    collisions beforehand or after catching an exception.

    :param data: Dictionary containing user data.
    :type data: dict
    """
    from invenio_accounts.models import User
    from invenio_userprofiles.api import UserProfile
    email = data['email'].strip()
    if User.query.filter_by(email=email).count() > 0:
        raise UserEmailExistsError(
            "User email '{email}' already exists.".format(email=email))

    last_login = None
    if data['last_login']:
        last_login = arrow.get(data['last_login']).datetime

    confirmed_at = None
    if data['note'] == '1':
        confirmed_at = datetime.utcnow()

    salt = data['password_salt']
    checksum = data['password']
    if not checksum:
        new_password = None
    # Test if password hash is in Modular Crypt Format
    elif checksum.startswith('$'):
        new_password = checksum
    else:
        new_password = str.join('$', ['', u'invenio-aes', salt, checksum])
    with db.session.begin_nested():
        obj = User(
            id=data['id'],
            password=new_password,
            email=email,
            confirmed_at=confirmed_at,
            last_login_at=last_login,
            active=(data['note'] != '0'),
        )
        db.session.add(obj)

    nickname = data['nickname'].strip()
    overwritten_username = ('username' in data and 'displayname' in data)
    # NOTE: 'username' and 'displayname' will exist in data dump only
    # if it was inserted there after dumping. It normally should not come from
    # Invenio 1.x or 2.x data dumper script. In such case, those values will
    # have precedence over the 'nickname' field.
    if nickname or overwritten_username:
        p = UserProfile(user=obj)
        p.full_name = data.get('full_name', '').strip()

        if overwritten_username:
            p._username = data['username'].lower()
            p._displayname = data['displayname']
        elif nickname:
            if UserProfile.query.filter(
                    UserProfile._username == nickname.lower()).count() > 0:
                raise UserUsernameExistsError(
                    "Username '{username}' already exists.".format(
                        username=nickname))
            try:
                p.username = nickname
            except ValueError:
                current_app.logger.warn(
                    u'Invalid username {0} for user_id {1}'.format(
                        nickname, data['id']))
                p._username = nickname.lower()
                p._displayname = nickname

        db.session.add(p)
    db.session.commit()
Load user from data dump.

    NOTE: This task takes into account the possible duplication of emails and
    usernames, hence it should be called synchronously.
    In such case of collision it will raise UserEmailExistsError or
    UserUsernameExistsError, if email or username are already existing in
    the database. Caller of this task should take care to to resolve those
    collisions beforehand or after catching an exception.

    :param data: Dictionary containing user data.
    :type data: dict