# coding: utf-8

from datetime import datetime, timedelta

from flask import Flask

from flask import session, request

from flask import render_template, redirect, jsonify

from flask_sqlalchemy import SQLAlchemy

from werkzeug.security import gen_salt

from flask_oauthlib.provider import OAuth2Provider

from settings.oauth_settings import OAuthSettings

app = Flask(__name__, template_folder='templates')

app.debug = True

app.secret_key = 'secret'

app.config.from_object(OAuthSettings)

app.config.update({

    'SQLALCHEMY_DATABASE_URI': 'sqlite:///db.sqlite',

})

db = SQLAlchemy(app)

oauth = OAuth2Provider(app)

class User(db.Model):

    id = db.Column(db.Integer, primary_key=True)

    username = db.Column(db.String(40), unique=True)

class Client(db.Model):

    client_id = db.Column(db.String(40), primary_key=True)

    client_secret = db.Column(db.String(55), nullable=False)

    _redirect_uris = db.Column(db.Text)

    _default_scopes = db.Column(db.Text)

    @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)

    expires = db.Column(db.DateTime)

    _scopes = db.Column(db.Text)

    @property

    def scopes(self):

        if self._scopes:

            return self._scopes.split()

        return []

def current_user():

    if 'id' in session:

        uid = session['id']

        return User.query.get(uid)

    return None

@app.route('/', methods=('GET', 'POST'))

def home():

    if request.method == 'POST':

        username = request.form.get('username')

        user = User.query.filter_by(username=username).first()

        if not user:

            user = User(username=username)

            db.session.add(user)

            db.session.commit()

        session['id'] = user.id

        return redirect('/')

    user = current_user()

    return render_template('oauth/home.html', user=user)

@oauth.clientgetter

def load_client(client_id):

    return Client.query.filter_by(client_id=client_id).first()

@oauth.grantgetter

def load_grant(client_id, code):

    return Grant.query.filter_by(client_id=client_id, code=code).first()

@oauth.grantsetter

def save_grant(client_id, code, request, *args, **kwargs):

    # decide the expires time yourself

    expires = datetime.utcnow() + timedelta(seconds=100)

    grant = Grant(

        client_id=client_id,

        code=code['code'],

        redirect_uri=request.redirect_uri,

        _scopes=' '.join(request.scopes),

        user=current_user(),

        expires=expires

    )

    db.session.add(grant)

    db.session.commit()

    return grant

@oauth.tokengetter

def load_token(access_token=None, refresh_token=None):

    if access_token:

        return Token.query.filter_by(access_token=access_token).first()

    elif refresh_token:

        return Token.query.filter_by(refresh_token=refresh_token).first()

@oauth.tokensetter

def save_token(token, request, *args, **kwargs):

    toks = Token.query.filter_by(

        client_id=request.client.client_id,

        user_id=request.user.id

    )

    # make sure that every client has only one token connected to a user

    for t in toks:

        db.session.delete(t)

    expires_in = token.pop('expires_in')

    expires = datetime.utcnow() + timedelta(seconds=expires_in)

    tok = Token(

        access_token=token['access_token'],

        token_type=token['token_type'],

        _scopes=token['scope'],

        expires=expires,

        client_id=request.client.client_id,

        user_id=request.user.id,

    )

    db.session.add(tok)

    db.session.commit()

    return tok

@oauth.token_handler

def access_token():

    return None

@oauth.authorize_handler

def authorize(*args, **kwargs):

    user = current_user()

    if not user:

        return redirect('/')

    if request.method == 'GET':

        client_id = kwargs.get('client_id')

        client = Client.query.filter_by(client_id=client_id).first()

        kwargs['client'] = client

        kwargs['user'] = user

        return render_template('oauth/authorize.html', **kwargs)

    confirm = request.form.get('confirm', 'no')

    return confirm == 'yes'

@oauth.require_oauth()

    user = request.oauth.user

    return jsonify(id=user.id, username=user.username)

if __name__ == '__main__':

    db.create_all()

    app.run()