004.erp.generic/backend/modules/fleet/tasks.py

# backend/modules/fleet/tasks.py
from celery import shared_task
from django.core.mail import send_mail
from django.conf import settings
import logging
from io import BytesIO
import base64
from PIL import Image, UnidentifiedImageError
from reportlab.lib.pagesizes import A4
from reportlab.lib.utils import ImageReader
from reportlab.pdfgen import canvas
from .models import VehicleNotification

logger = logging.getLogger(__name__)


@shared_task(bind=True, max_retries=3, default_retry_delay=60)
def send_notification_email(self, notification_id):
    """
    Celery task koji pošalje e-mail za VehicleNotification i označi is_sent = True.
    Prihvaća notification_id (PK) i radi safe-lookup.
    U slučaju greške rekreira retry.
    """
    try:
        # Lokalni import kako bismo izbjegli kružne importove
        from .models import VehicleNotification
        notif = VehicleNotification.objects.select_related('recipient').get(pk=notification_id)
    except Exception as exc:
        logger.warning(f"Notification {notification_id} ne postoji ili nije dostupna: {exc}")
        return

    recipient = notif.recipient
    recipient_email = getattr(recipient, 'email', None) if recipient else None

    if not recipient_email:
        logger.info(f"Notification {notification_id} nema email primatelja; preskačem slanje.")
        return

    subject = notif.title
    message = notif.message
    from_email = getattr(settings, "DEFAULT_FROM_EMAIL", None)

    try:
        send_mail(
            subject=subject,
            message=message,
            from_email=from_email,
            recipient_list=[recipient_email],
            fail_silently=False,
        )
        notif.is_sent = True
        notif.save(update_fields=['is_sent'])
        logger.info(f"Notification email poslan za Notification(id={notification_id}) na {recipient_email}")
    except Exception as exc:
        logger.exception(f"Greška pri slanju emaila za Notification(id={notification_id}): {exc}")
        try:
            # Retry with exponential backoff handled by celery config; here max_retries = 3
            raise self.retry(exc=exc)
        except self.MaxRetriesExceededError:
            logger.error(f"Max retries exceeded za Notification(id={notification_id})")

@shared_task
def send_email_task(recipient_email, subject, message, notif_id):
    try:
        send_mail(
            subject=subject,
            message=message,
            from_email=settings.DEFAULT_FROM_EMAIL,
            recipient_list=[recipient_email],
            fail_silently=False,
        )
        VehicleNotification.objects.filter(id=notif_id).update(is_sent=True)
    except Exception as exc:
        logger.error(f"Async mail failed: {exc}")


def _build_work_order_invoices_pdf(work_order):
    buffer = BytesIO()
    pdf = canvas.Canvas(buffer, pagesize=A4)
    width, height = A4
    y = height - 50

    pdf.setFont("Helvetica-Bold", 14)
    pdf.drawString(40, y, f"Računi putnog naloga WO-{work_order.pk}")
    y -= 22
    pdf.setFont("Helvetica", 10)
    pdf.drawString(40, y, f"Dizalica: {work_order.vehicle.registration_number}")
    y -= 16
    pdf.drawString(40, y, f"Datum naloga: {work_order.date}")

    invoices = work_order.invoices.filter(is_active=True).order_by('-datum', '-created_at')
    if not invoices.exists():
        y -= 24
        pdf.drawString(40, y, "Nema računa za ovaj putni nalog.")
        pdf.save()
        return buffer.getvalue()

    for index, invoice in enumerate(invoices, start=1):
        pdf.showPage()
        y = height - 50
        pdf.setFont("Helvetica-Bold", 13)
        pdf.drawString(40, y, f"Račun #{index}")
        y -= 22
        pdf.setFont("Helvetica", 10)
        pdf.drawString(40, y, f"naziv_racuna: {invoice.naziv_racuna or '-'}")
        y -= 16
        pdf.drawString(40, y, f"lokacija: {invoice.lokacija or '-'}")
        y -= 16
        pdf.drawString(40, y, f"datum: {invoice.datum.strftime('%d.%m.%Y') if invoice.datum else '-'}")
        y -= 16
        pdf.drawString(40, y, f"opis: {(invoice.opis or '-')[:140]}")
        y -= 20

        if not invoice.image:
            pdf.drawString(40, y, "slika: Nema slike.")
            continue

        try:
            invoice.image.open('rb')
            with Image.open(invoice.image) as source:
                image = source.convert('RGB')
                max_width = width - 80
                max_height = y - 60
                if max_height < 120:
                    pdf.showPage()
                    y = height - 60
                    max_height = y - 60

                ratio = min(max_width / float(image.width), max_height / float(image.height), 1.0)
                draw_width = max(1, int(image.width * ratio))
                draw_height = max(1, int(image.height * ratio))
                image_reader = ImageReader(image)
                pdf.drawImage(
                    image_reader,
                    40,
                    y - draw_height,
                    width=draw_width,
                    height=draw_height,
                    preserveAspectRatio=True,
                    mask='auto',
                )
        except (UnidentifiedImageError, OSError):
            pdf.drawString(40, y, "slika: Slika nije dostupna ili je oštećena.")
        finally:
            invoice.image.close()

    pdf.save()
    return buffer.getvalue()


@shared_task
def build_work_order_invoices_pdf_task(work_order_id):
    from .models import WorkOrder

    work_order = WorkOrder.objects.select_related('vehicle').filter(pk=work_order_id).first()
    if work_order is None:
        return {"error": "Putni nalog nije pronađen."}

    pdf_bytes = _build_work_order_invoices_pdf(work_order)
    pdf_b64 = base64.b64encode(pdf_bytes).decode('ascii')
    filename = f"{work_order.pk}.work-order-invoices.pdf"
    return {
        "filename": filename,
        "pdf_base64": pdf_b64,
    }