from datetime import date, timedelta

from django.core.management.base import BaseCommand, CommandError
from django.template.loader import get_template
from django.core.mail import send_mail, BadHeaderError

from input.models import Project, Library
from input.settings import URLPREFIX, IF_EMAIL

class Command(BaseCommand):
    ''' mails will be send here:

    - two weeks after confirmation of support for volunteer (/extern) send link
    with surveylink

    - same for HonoraryCertificate and accreditation (/intern)

    - travel: mail 3 weeks after end of project.

    - assumed end of project (/project) reached: mail to IF, link to project-editpage

    - 4 weeks after end of project reached: mail with surveylink
    '''

    help = '''This command sends mail with some links to the database or to the survey
              after some amount of time.'''

    def survey_link(self, email, type, pid, name, realname):
            print(f'send surveylinkemail to {email}...')

    def end_of_projects_reached(self):
        ''' end of project reached '''
        # get all projects which ended
        # - timedelta(days=21))
        old = Project.objects.filter(end__lt = date.today())\
                             .exclude(end_mail_send = True)

        mail_template = get_template('input/if_end_of_project.txt')
        for project in old:
            context = {'project': project}
            context['URLPREFIX'] = URLPREFIX
            print(context)
            try:
                send_mail('Projektende erreicht',
                          mail_template.render(context),
                          IF_EMAIL,
                          [IF_EMAIL],
                          fail_silently=False)
                project.end_mail_send = True
                project.save()
            except BadHeaderError:
                return HttpResponse('Invalid header found.')

        self.stdout.write(self.style.SUCCESS('end_of_projects_reached() executed.'))


    def handle(self, *args, **options):

        self.end_of_projects_reached()

        supported = Library.objects.filter(granted=True)
        print(supported)
        for item in supported:
            self.survey_link(email=item.email,
                             type=item.type,
                             pid=9999, ## TODO
                             name=item.library,
                             realname=item.realname)

        self.stdout.write(self.style.SUCCESS('sendmails custom command executed'))