# backend/modules/task_management/tasks.py

import logging
from celery import shared_task
from .models import Task
from django.contrib.auth import get_user_model
from modules.fleet.models import Vehicle, WorkOrder

logger = logging.getLogger(__name__)


@shared_task
def notify_upcoming_tasks():
    """
    Dnevna Celery periodik task koji šalje Pusher + email notifikacije
    za radne zadatke čiji je planirani datum izvršenja sutra.
    """
    from datetime import date, timedelta
    from modules.fleet.services import NotificationService

    tomorrow = date.today() + timedelta(days=1)
    upcoming = Task.objects.filter(
        is_active=True,
        scheduled_date=tomorrow,
        status__in=('aktivan', 'servis'),
    ).select_related('assigned_to', 'vehicle')

    notified = 0
    for task in upcoming:
        recipient = task.assigned_to
        if not recipient:
            continue
        vehicle_label = (
            task.vehicle.registration_number if task.vehicle else 'nepoznato'
        )
        try:
            NotificationService.create_notification(
                recipient=recipient,
                title=f"Sutra planirani zadatak: {task.title}",
                message=(
                    f"Radni zadatak '{task.title}' na dizalici {vehicle_label} "
                    f"je planiran za sutra ({tomorrow.strftime('%d.%m.%Y')})."
                ),
                level="info",
                send_email=True,
                metadata={
                    "entity_type": "task",
                    "task_id": str(task.id),
                    "vehicle_id": str(task.vehicle_id) if task.vehicle_id else None,
                    "section": "dashboard",
                    "scheduled_date": tomorrow.isoformat(),
                },
            )
            notified += 1
        except Exception:
            logger.exception("Greška pri slanju notifikacije za task %s", task.id)

    logger.info("notify_upcoming_tasks: obaviješteno %d servisera za datum %s", notified, tomorrow)
    return {"notified": notified, "date": tomorrow.isoformat()}


@shared_task
def create_task_from_invoice(invoice_data):
    """
    Ovaj zadatak se poziva asinkrono.
    """
    User = get_user_model()
    # Logika: dodijeli zadatak adminu ako je račun veći od 1000
    amount = float(invoice_data.get('amount', 0))
    admin_user = User.objects.filter(is_staff=True).first()
    work_order = None
    vehicle = None
    work_order_id = invoice_data.get('work_order_id')
    vehicle_id = invoice_data.get('vehicle_id')

    if work_order_id:
        work_order = WorkOrder.objects.filter(pk=work_order_id).first()
        if work_order:
            vehicle = work_order.vehicle
    if vehicle is None and vehicle_id:
        vehicle = Vehicle.objects.filter(pk=vehicle_id).first()

    if amount > 1000:
        Task.objects.create(
            title=f"Provjera računa: {invoice_data['invoice_number']}",
            description=f"Račun iznosi {amount}, potrebna revizija.",
            assigned_to=admin_user,
            status='aktivan',
            vehicle=vehicle,
            work_order=work_order,
        )