from datetime import timedelta

from django.conf import settings
from django.db import migrations
from django.db.models import Q
from django.utils import timezone


SAFE_0098_RESULTS = (
    ("UNDELIVERED", "6"),
    ("EXPIRED", "7"),
    ("ERROR", "-31"),
)


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


def queue_historical_safe_0098_delivery_retries(apps, schema_editor):
    """Queue one delayed resend for old individual staff-ticket SMS jobs."""
    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)
    max_checks = getattr(settings, "SMS_DELIVERY_MAX_CHECKS", 15)
    now = timezone.now()
    monitor_cutoff = now - timedelta(seconds=delay)
    safe_result = (
        Q(delivery_status="EXPIRED", delivery_status_code="7")
        | Q(delivery_status="ERROR", delivery_status_code="-31")
        | Q(delivery_status="UNDELIVERED", delivery_status_code="6", sent_at__lte=monitor_cutoff)
        | Q(delivery_status="UNDELIVERED", delivery_status_code="6", delivery_check_attempts__gte=max_checks)
    )
    sources = NotificationJob.objects.filter(
        safe_result,
        channel="SMS",
        event_type="STAFF_TICKET_CREATED",
        status="SENT",
        ticket__group_dispatch__isnull=True,
        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,
        )
        NotificationJob.objects.filter(pk=source.pk).update(delivery_is_final=True)
        queued += 1


class Migration(migrations.Migration):
    dependencies = [("notifications", "0013_notificationjob_definitive_delivery_retry")]

    operations = [
        migrations.RunPython(
            queue_historical_safe_0098_delivery_retries,
            migrations.RunPython.noop,
        ),
    ]