from datetime import date

from django.contrib.auth.models import User
from django.core.management.base import BaseCommand, CommandError

from fiches.models import Department, Profile

from ._ldap import ClipperLDAP


class Command(BaseCommand):
    help = "Crée les fiches annuaire des conscrit·e·s automatiquement"

    def add_arguments(self, parser):
        group = parser.add_mutually_exclusive_group()
        group.add_argument(
            "--all", action="store_true", help="Importe l'intégralité des promotions"
        )
        group.add_argument("--promo", type=int, help="Spécifie la promotion à importer")

    def get_current_promo(self):
        today = date.today()
        year = today.year
        if today.month < 9:
            year -= 1

        return year

    def handle(self, *args, **options):
        if options["all"]:
            promo = None
        elif options["promo"] is not None:
            promo = options["promo"]
            if promo < 100:
                promo = 2000 + promo
        else:
            promo = self.get_current_promo()

        if promo < 2000 or promo > 2100:
            raise CommandError("Promotion invalide : {}".format(promo))

        verbosity = options["verbosity"]

        # On récupère la liste des élèves à créer
        ldap = ClipperLDAP()
        clipper_list = ldap.get_clipper_list(
            promo_filter=promo, verbosity=verbosity, stdout=self.stdout
        )

        # On vire les élèves déjà existants
        existing_users = set(User.objects.values_list("username", flat=True))
        clippers = [
            clipper for clipper in clipper_list if clipper.uid not in existing_users
        ]

        # Les départements sont créés à la main ; il y en a peu.
        depts = {
            dept: Department.objects.get_or_create(name=dept)[0].id
            for dept in ldap.verbose_depts.values()
        }

        users_to_create = []
        profiles_to_create = []
        dept_m2m_to_create = []

        for clipper in clippers:
            user = User(username=clipper.uid, email=clipper.email)
            profile = Profile(user=user, full_name=clipper.name, promotion=clipper.year)
            users_to_create.append(user)
            profiles_to_create.append(profile)
            dept_m2m_to_create.append(
                Profile.department.through(
                    profile=profile, department_id=depts[clipper.dept]
                )
            )

        # À décommenter pour utilisation locale (avec SQLite)

        # def _manual_ids(cls, to_create):
        #     pid = getattr(cls.objects.order_by("-id").first(), "id", 1)
        #     for p in to_create:
        #         pid += 1
        #         p.id = pid

        # _manual_ids(User, users_to_create)
        # _manual_ids(Profile, profiles_to_create)
        # _manual_ids(Profile.department.through, dept_m2m_to_create)

        User.objects.bulk_create(users_to_create)
        for profile in profiles_to_create:
            profile.user_id = profile.user.id
        Profile.objects.bulk_create(profiles_to_create)
        for dept_m2m in dept_m2m_to_create:
            dept_m2m.profile_id = dept_m2m.profile.id
        Profile.department.through.objects.bulk_create(dept_m2m_to_create)

        if verbosity >= 1:
            self.stdout.write(
                (
                    "Création de {} utilisateur·ices et de {}"
                    " profils effectuée avec succès"
                ).format(len(users_to_create), len(profiles_to_create))
            )