# -*- mode: python; coding: utf-8 -*-
# Copyright (C) 2017-2021 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 _


class User(AbstractUser):
    phone_number = models.CharField(
        verbose_name=_('phone number'),
        max_length=15,
        blank=True,
    )
    address = models.CharField(
        verbose_name=_('address'),
        max_length=255,
        blank=True,
    )
    comment = models.CharField(
        verbose_name=_('comment'),
        help_text=_('Promotion...'),
        max_length=255,
        blank=True,
    )
    date_joined = models.DateTimeField(
        verbose_name=_('date joined'),
        default=timezone.now,
        null=True,
    )

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

    @property
    def is_member(self):
        """
        Return True if user is member of the club.
        """
        return Membership.objects.filter(
            user=self,
            date_start__lte=timezone.now(),
            date_end__gte=timezone.now()).exists()

    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.phone_number = data['profile']['phone_number']
        self.address = data['profile']['address']
        self.comment = data['profile']['section']

        for membership_dict in data['memberships']:
            if membership_dict['club'] != 22:  # Med
                continue
            # Add membership if not exists
            Membership.objects.get_or_create(
                user=self,
                date_start=membership_dict['date_start'],
                date_end=membership_dict['date_end'],
            )

        # Only members or old members are allow to connect to the website
        self.is_active = Membership.objects.filter(user=self).exists()


class Membership(models.Model):
    user = models.ForeignKey(
        User,
        on_delete=models.CASCADE,
        verbose_name=_('user'),
    )

    date_start = models.DateField(
        auto_now_add=True,
        verbose_name=_('start date'),
    )

    date_end = models.DateField(
        auto_now_add=True,
        verbose_name=_('start date'),
    )

    def __str__(self):
        return f'{self.user}: {self.date_start} to {self.date_end}'

    class Meta:
        verbose_name = _('membership')
        verbose_name_plural = _('memberships')


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.
        """
        data = requests.get(f'{settings.NOTE_KFET_URL}/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()

        # Store token owner
        self.owner = user
        self.save()

        return user

    @classmethod
    def get_token(cls, request):
        return AccessToken.objects.get(pk=request.session['access_token_id'])

    def __str__(self):
        return self.access_token

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