# app/modules/loyalty/tasks/notifications.py
"""
Async email notification dispatch for loyalty events.

All loyalty notification emails are sent asynchronously via this Celery
task to avoid blocking request handlers.  The task opens its own DB
session and calls EmailService.send_template() which handles language
resolution, store overrides, Jinja2 rendering, and EmailLog creation.
"""

import logging

from celery import shared_task

logger = logging.getLogger(__name__)


@shared_task(
    name="loyalty.send_notification_email",
    bind=True,
    max_retries=3,
    default_retry_delay=60,
)
def send_notification_email(
    self,
    template_code: str,
    to_email: str,
    to_name: str | None = None,
    variables: dict | None = None,
    store_id: int | None = None,
    customer_id: int | None = None,
    language: str | None = None,
):
    """
    Send a loyalty notification email asynchronously.

    Args:
        template_code: Email template code (e.g. 'loyalty_enrollment')
        to_email: Recipient email address
        to_name: Recipient display name
        variables: Template variables dict
        store_id: Store ID for branding and template overrides
        customer_id: Customer ID for language resolution
        language: Explicit language override (otherwise auto-resolved)
    """
    from app.core.database import SessionLocal
    from app.modules.messaging.services.email_service import EmailService

    db = SessionLocal()
    try:
        email_service = EmailService(db)
        email_log = email_service.send_template(
            template_code=template_code,
            to_email=to_email,
            to_name=to_name,
            language=language,
            variables=variables or {},
            store_id=store_id,
            customer_id=customer_id,
        )
        logger.info(
            f"Loyalty notification sent: {template_code} to {to_email} "
            f"(log_id={email_log.id if email_log else 'none'})"
        )
    except Exception as exc:
        logger.error(
            f"Loyalty notification failed: {template_code} to {to_email}: {exc}"
        )
        db.rollback()
        raise self.retry(exc=exc)
    finally:
        db.close()