models.py

# models.py
from flask_sqlalchemy import SQLAlchemy
from flask_login import UserMixin

db = SQLAlchemy()


class User(UserMixin, db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(40), unique=True)  # this will be removed
    #
    email = db.Column(db.String(100), unique=True)
    password = db.Column(db.String(100))
    name = db.Column(db.String(1000))


class Client(db.Model):
    client_id = db.Column(db.String(40), primary_key=True)
    client_secret = db.Column(
        db.String(55), unique=True, index=True, nullable=False)
    # creator of the client, not required
    user_id = db.Column(db.ForeignKey('user.id'))
    user = db.relationship('User')

    _redirect_uris = db.Column(db.Text)
    _default_scopes = db.Column(db.Text)

    @property
    def client_type(self):
        return 'public'

    @property
    def redirect_uris(self):
        if self._redirect_uris:
            return self._redirect_uris.split()
        return []

    @property
    def default_redirect_uri(self):
        return self.redirect_uris[0]

    @property
    def default_scopes(self):
        if self._default_scopes:
            return self._default_scopes.split()
        return []


class Grant(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    user_id = db.Column(
        db.Integer, db.ForeignKey('user.id', ondelete='CASCADE')
    )
    user = db.relationship('User')
    client_id = db.Column(
        db.String(40), db.ForeignKey('client.client_id'),
        nullable=False,
    )
    client = db.relationship('Client')
    code = db.Column(db.String(255), index=True, nullable=False)
    redirect_uri = db.Column(db.String(255))
    expires = db.Column(db.DateTime)

    _scopes = db.Column(db.Text)

    def delete(self):
        db.session.delete(self)
        db.session.commit()
        return self

    @property
    def scopes(self):
        if self._scopes:
            return self._scopes.split()
        return []


class Token(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    client_id = db.Column(
        db.String(40), db.ForeignKey('client.client_id'),
        nullable=False,
    )
    client = db.relationship('Client')
    user_id = db.Column(
        db.Integer, db.ForeignKey('user.id')
    )
    user = db.relationship('User')
    # currently only bearer is supported
    token_type = db.Column(db.String(40))

    access_token = db.Column(db.String(255), unique=True)
    refresh_token = db.Column(db.String(255), unique=True)
    expires = db.Column(db.DateTime)
    _scopes = db.Column(db.Text)

    @property
    def scopes(self):
        if self._scopes:
            return self._scopes.split()
        return []