from django.conf import settings
from django.db import migrations


def backfill_memberships(apps, schema_editor):
    NetworkMap = apps.get_model('contacts', 'NetworkMap')
    NetworkMapMembership = apps.get_model('contacts', 'NetworkMapMembership')
    Relation = apps.get_model('contacts', 'Relation')
    Contact = apps.get_model('contacts', 'Contact')
    User = apps.get_model('auth', 'User')

    def backfill_for_owner(owner_id):
        if owner_id is None:
            maps = NetworkMap.objects.filter(owner__isnull=True).order_by('id')
            relations = Relation.objects.filter(owner__isnull=True)
            contact_owner_filter = {'owner__isnull': True}
        else:
            maps = NetworkMap.objects.filter(owner_id=owner_id).order_by('id')
            relations = Relation.objects.filter(owner_id=owner_id)
            contact_owner_filter = {'owner_id': owner_id}

        if not maps.exists():
            return 0
        if NetworkMapMembership.objects.filter(map__in=maps).exists():
            return 0

        contact_ids = set()
        for relation in relations.only('source_id', 'target_id'):
            contact_ids.add(relation.source_id)
            contact_ids.add(relation.target_id)
        if not contact_ids:
            return 0

        contacts = Contact.objects.filter(id__in=contact_ids, **contact_owner_filter)
        target_map = maps.first()
        created = 0
        for contact in contacts:
            _, was_created = NetworkMapMembership.objects.get_or_create(
                map=target_map,
                contact=contact,
                defaults={
                    'life_sphere': 'other',
                    'network_circle': 'productivity',
                    'importance': 3,
                    'conflict_involvement': 3,
                },
            )
            if was_created:
                created += 1
        return created

    total = backfill_for_owner(None)
    for user in User.objects.all():
        total += backfill_for_owner(user.id)
    if total:
        print(f'Backfilled {total} network map memberships')


class Migration(migrations.Migration):

    dependencies = [
        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
        ('contacts', '0011_add_owner'),
    ]

    operations = [
        migrations.RunPython(backfill_memberships, migrations.RunPython.noop),
    ]