# -*- mode: python; coding: utf-8 -*-
# Copyright (C) 2017-2019 by BDE ENS Paris-Saclay
# SPDX-License-Identifier: GPL-3.0-or-later

from datetime import datetime

import requests
from authlib.integrations.django_client import OAuth
from django.conf import settings
from django.contrib.auth.models import AbstractUser
from django.db import models
from django.db.models import Q
from django.utils import timezone
from django.utils.translation import gettext_lazy as _
from med.settings import MAX_EMPRUNT


class User(AbstractUser):
    telephone = models.CharField(
        verbose_name=_('phone number'),
        max_length=15,
        blank=True,
    )
    address = models.CharField(
        verbose_name=_('address'),
        max_length=255,
        blank=True,
    )
    maxemprunt = models.IntegerField(
        verbose_name=_('maximum borrowed'),
        help_text=_('Maximal amount of simultaneous borrowed item '
                    'authorized.'),
        default=MAX_EMPRUNT,
    )
    comment = models.CharField(
        verbose_name=_('comment'),
        help_text=_('Promotion...'),
        max_length=255,
        blank=True,
    )
    date_joined = models.DateTimeField(
        _('date joined'),
        default=timezone.now,
        null=True,
    )

    REQUIRED_FIELDS = ['first_name', 'last_name', 'email']

    @property
    def is_member(self):
        # FIXME Use NK20
        return True

    def update_data(self, data: dict):
        """
        Update user data from given dictionary.
        Useful when we want to update user data from Note Kfet.

        Parameters
        ----------
        data : dict
            Dictionary with user data to update.
        """
        self.email = data['email']
        self.first_name = data['first_name']
        self.last_name = data['last_name']
        self.telephone = data['profile']['phone_number']
        self.address = data['profile']['address']
        self.comment = data['profile']['section']


class AccessToken(models.Model):
    owner = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        null=True,
        default=None,
        verbose_name=_('owner'),
    )

    access_token = models.CharField(
        max_length=32,
        verbose_name=_('access token'),
    )

    expires_in = models.PositiveSmallIntegerField(
        verbose_name=_('expires in'),
    )

    scopes = models.CharField(
        max_length=255,
        verbose_name=_('scopes'),
    )

    refresh_token = models.CharField(
        max_length=32,
        verbose_name=_('refresh token'),
    )

    expires_at = models.DateTimeField(
        verbose_name=_('expires at'),
    )

    def refresh(self):
        """
        Refresh the access token.
        """
        oauth = OAuth()
        oauth.register('notekfet')
        # Get the OAuth client
        oauth_client = oauth.notekfet._get_oauth_client()
        # Actually refresh the token
        token = oauth_client.refresh_token(oauth.notekfet.access_token_url,
                                           refresh_token=self.refresh_token)
        self.access_token = token['access_token']
        self.expires_in = token['expires_in']
        self.scopes = token['scope']
        self.refresh_token = token['refresh_token']
        self.expires_at = timezone.utc.fromutc(
            datetime.fromtimestamp(token['expires_at'])
        )

        self.save()

    def refresh_if_expired(self):
        """
        Refresh the current token if it is invalid.
        """
        if self.expires_at < timezone.now():
            self.refresh()

    def auth_header(self):
        """
        Return HTTP header that contains the bearer access token.
        Refresh the token if needed.
        """
        self.refresh_if_expired()
        return {'Authorization': f'Bearer {self.access_token}'}

    def fetch_user(self, create_if_not_exist: bool = False):
        """
        Extract information about the Note Kfet API by using the current
        access token.
        """
        if self.owner:
            return self.owner

        data = requests.get('https://note-dev.crans.org/api/me/',
                            headers=self.auth_header()).json()
        username = data['username']
        email = data['email']
        qs = User.objects.filter(Q(username=username) | Q(email=email))
        if not qs.exists():
            if create_if_not_exist:
                user = User.objects.create(username=username, email=email)
            else:
                return None
        else:
            user = qs.get()

        # Update user data from Note Kfet
        user.update_data(data)
        user.save()

        return user

    class Meta:
        verbose_name = _('access token')
        verbose_name_plural = _('access tokens')