class Company(db.Model):
    """ Company representation in the system """

    __tablename__ = 'companies'

    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(), nullable=False, index=True)
    description = db.Column(db.Text())
    start_date = db.Column(db.Date(), index=True)
    city = db.Column(db.String())
    created_at = db.Column(db.DateTime(), default=datetime.datetime.now)
    updated_at = db.Column(db.DateTime(), onupdate=datetime.datetime.now)

    employees = db.relationship('CompanyUser', backref=db.backref('companies', lazy=True))

class User(db.Model):
    """ User representation in the system """

    __tablename__ = 'users'

    id = db.Column(db.Integer, primary_key=True)
    email = db.Column(db.String(), unique=True, nullable=False)
    first_name = db.Column(db.String())
    last_name = db.Column(db.String())
    password_digest = db.Column(db.String(), nullable=False)

    companies = db.relationship('CompanyUser', backref=db.backref('users', lazy=True))

    def __init__(self, **kwargs):
        password = kwargs.pop('password', None)
        super(User, self).__init__(**kwargs)
        self.password_digest = self.set_password(password)

    def set_password(self, password):
        """ Hash and store password """

        return bcrypt.hashpw(
            password.encode(), bcrypt.gensalt()
        ).decode('utf8')

    def authenticate(self, password):
        """ Authenticate user; Check if user's password match the given one """

        return bcrypt.checkpw(password.encode(), self.password_digest.encode())


class CompanyUser(db.Model):
    """ Association object class for company and user"""

    __tablename__ = 'company_users'

    company_id = db.Column(
        db.Integer, db.ForeignKey('companies.id'), primary_key=True, nullable=False
    )
    user_id = db.Column(
        db.Integer, db.ForeignKey('users.id'), primary_key=True, nullable=False
    )
    role = db.Column(db.Integer, index=True)
    created_at = db.Column(db.DateTime(), default=datetime.datetime.now)
    updated_at = db.Column(db.DateTime(), onupdate=datetime.datetime.now)

company = Company(**params)
company_user = CompanyUser(
                role=self.DEFAULT_ROLE
            )
company.employees.append(company_user)
self.current_user.companies.append(company_user)
db.session.add(company)
db.session.commit()