from datetime import datetime

from django.contrib.auth import get_user_model
from django.contrib.staticfiles.storage import staticfiles_storage
from django.utils.timezone import now

from apps.notification.models import UserNotification
from apps.notification.utils import send_email
from apps.payment.models import SchoolPayment
from project.celery import app


User = get_user_model()


@app.task
def send_certificates(email=None, date=None, dry_run=False):
    path_pattern = 'img/user-certificates/%d.jpg'
    if email:
        file = open(staticfiles_storage.path(path_pattern % 1), 'rb')
        try:
            send_email('Грамота от Lil School', email, 'notification/email/certificate.html',
                       attachments=[(file.name, file.read(), 'image/jpeg')])
        except:
            pass
        else:
            print('Email has been sent')
        finally:
            file.close()
            return

    date = datetime.strptime(date, '%d-%m-%Y') if date else now().date()
    today = now().date()
    users = set(list(SchoolPayment.objects.filter(date_end=date, add_days=False).values_list('user_id', flat=True)))
    user_notifications_qs = UserNotification.objects.filter(user_id__in=users)
    user_notifications = {un.user_id: un for un in user_notifications_qs}
    notified_users = user_notifications_qs.filter(certificate_last_email__date=today).values_list(
        'user_id', flat=True).distinct()
    for user_id in users:
        if user_id in notified_users:
            continue
        un = user_notifications.get(user_id, UserNotification(user_id=user_id))
        print(un.user.email)
        if dry_run:
            continue

        un.certificate_number = un.certificate_number + 1 \
            if un.certificate_number and staticfiles_storage.exists(path_pattern % (un.certificate_number + 1)) \
            else 1
        file = open(staticfiles_storage.path(path_pattern % un.certificate_number), 'rb')
        try:
            send_email('Грамота от Lil School', un.user.email, 'notification/email/certificate.html',
                       attachments=[(file.name, file.read(), 'image/jpeg')])
        except:
            print('Not OK')
            continue
        finally:
            file.close()
        un.certificate_last_email = now()
        un.save()