from datetime import timedelta

from django.conf import settings
from django.db import migrations, models
import django.db.models.deletion
from django.utils import timezone


def _retry_dedupe_key(job):
    suffix = f":definitive-delivery-retry:{job.pk}"
    return f"{job.dedupe_key[:200-len(suffix)]}{suffix}"


def queue_historical_definitive_delivery_retries(apps, schema_editor):
    """Queue each old, definitively expired individual staff-created SMS once."""
    NotificationJob = apps.get_model("notifications", "NotificationJob")
    delay = getattr(settings, "SMS_DEFINITIVE_DELIVERY_RETRY_AFTER_SECONDS", 2700)
    stagger = getattr(settings, "SMS_HISTORICAL_DELIVERY_RETRY_STAGGER_SECONDS", 30)
    now = timezone.now()
    sources = NotificationJob.objects.filter(
        channel="SMS",
        event_type="STAFF_TICKET_CREATED",
        status="SENT",
        ticket__group_dispatch__isnull=True,
        delivery_status="EXPIRED",
        delivery_next_check_at__isnull=True,
        delivery_retry_source__isnull=True,
    ).order_by("id")
    queued = 0
    for source in sources.iterator():
        if NotificationJob.objects.filter(delivery_retry_source_id=source.pk).exists():
            continue
        sent_at = source.sent_at or source.created_at
        due = max(sent_at + timedelta(seconds=delay), now + timedelta(seconds=(queued + 1) * stagger))
        NotificationJob.objects.create(
            channel=source.channel,
            event_type=source.event_type,
            customer_id=source.customer_id,
            staff_user_id=source.staff_user_id,
            ticket_id=source.ticket_id,
            payload=source.payload,
            status="PENDING",
            attempts=0,
            next_attempt_at=due,
            dedupe_key=_retry_dedupe_key(source),
            delivery_retry_source_id=source.pk,
        )
        queued += 1


class Migration(migrations.Migration):
    dependencies = [("notifications", "0012_supervisor_sms_template")]

    operations = [
        migrations.AddField(
            model_name="notificationjob",
            name="delivery_is_final",
            field=models.BooleanField(default=False),
        ),
        migrations.AddField(
            model_name="notificationjob",
            name="delivery_retry_source",
            field=models.OneToOneField(
                blank=True,
                null=True,
                on_delete=django.db.models.deletion.CASCADE,
                related_name="delivery_retry_job",
                to="notifications.notificationjob",
            ),
        ),
        migrations.RunPython(queue_historical_definitive_delivery_retries, migrations.RunPython.noop),
    ]