vontor-cz/backend/thirdparty/zasilkovna/models.py

"""Models for integration with Packeta (Zásilkovna) API.

These models wrap calls to the SOAP API via the immutable client defined in
`client.py` (PacketaAPI). DO NOT modify the client; we only consume it here.

Workflow:
 - Create a `PacketaPacket` instance locally with required recipient data.
 - On first save (when `packet_id` is empty) call the remote API to create
   the packet and persist the returned identifier + metadata.
 - Use helper methods to refresh remote info, fetch label PDF, cancel packet.
 - Group packets into a `PacketaShipment` and create shipment remotely.

Edge cases handled:
 - API faults raise exceptions (to be surfaced by serializer validation).
 - Missing remote fields are stored in `metadata` JSON.
 - Label PDF stored as binary field; can be re-fetched if empty.
"""

import json
from django.db import models
from django.utils import timezone
from django.core.validators import RegexValidator
from django.core.files.base import ContentFile
from django.apps import apps

from .client import PacketaAPI

from configuration.models import ShopConfiguration

packeta_client = PacketaAPI()  # single reusable instance


class ZasilkovnaPacket(models.Model):
    created_at = models.DateTimeField(auto_now_add=True)
    
    class STATE(models.TextChoices):
        PENDING = "PENDING", "Podáno"
        SENDED = "SENDED", "Odesláno"
        ARRIVED = "ARRIVED", "Doručeno"
        CANCELED = "CANCELED", "Zrušeno"

        RETURNING = "RETURNING", "Posláno zpátky"
        RETURNED = "RETURNED", "Vráceno"
    state = models.CharField(max_length=20, choices=STATE.choices, default=STATE.PENDING)

    # ------- API -------
    #TODO: změnit na nastavení adresy eshopu/obchodu z modelu konfigurace
    # https://client.packeta.com/cs/senders  (admin rozhraní)
    
    addressId = models.IntegerField(help_text="ID adresy, v Widgetu zásilkovny který si vybere uživatel.")
    
    packet_id = models.IntegerField(help_text="Číslo zásilky v Packetě (api)")
    barcode = models.CharField(max_length=64, help_text="Čárový kód zásilky v Packetě")

    weight = models.IntegerField(
        default=0,
        help_text="Hmotnost zásilky v gramech"
    )

    # 🚚 návratové směrovací kódy (pro vrácení zásilky)
    return_routing = models.JSONField(
        default=list,
        blank=True,
        help_text="Seznam 2 routing stringů pro vrácení zásilky"
    )

    class PDF_SIZE(models.TextChoices):
        A6_ON_A6 = ("A6 on A6", "105x148 mm (A6) label on a page of the same size")
        A7_ON_A7 = ("A7 on A7", "105x74 mm (A7) label on a page of the same size")
        A6_ON_A4 = ("A6 on A4", "105x148 mm (A6) label on a page of size 210x297 mm (A4)")
        A7_ON_A4 = ("A7 on A4", "105x74 mm (A7) label on a page of size 210x297 mm (A4)")
        A8_ON_A8 = ("A8 on A8", "50x74 mm (A8) label on a page of the same size")
    size_of_pdf = models.CharField(max_length=20, choices=PDF_SIZE.choices, default=PDF_SIZE.A6_ON_A6)

    def save(self, *args, **kwargs):
        # workaroud to avoid circular import
        Carrier = apps.get_model('commerce', 'Carrier')
        Order = apps.get_model('commerce', 'Order')

        carrier = Carrier.objects.get(zasilkovna=self)
        order = Order.objects.get(carrier=carrier)

        cash_on_delivery = order.payment.payment_method == order.payment.PAYMENT.CASH_ON_DELIVERY

        if not self.packet_id:
            response = packeta_client.create_packet(
                address_id=self.addressId,
                weight=self.weight,
                number=order.id,
                name=order.first_name,
                surname=order.last_name,
                company=order.company,
                email=order.email,
                addressId=ShopConfiguration.get_solo().zasilkovna_address_id,
                
                cod=order.total_price if cash_on_delivery else 0, # dobírka
                value=order.total_price,

                currency=ShopConfiguration.get_solo().currency,
                eshop= ShopConfiguration.get_solo().name,
            )
            self.packet_id = response['packet_id']
            self.barcode = response['barcode']

        return super().save(args, **kwargs)

    def cancel_packet(self):
        """Cancel this packet via the Packeta API."""
        packeta_client.cancel_packet(self.packet_id)
        self.state = self.STATE.CANCELED
        self.save()  # persist state change

    def get_tracking_url(self):
        """Vrátí veřejnou URL pro sledování zásilky (Zásilkovna.cz)."""
        base_url = "https://www.zasilkovna.cz/vyhledavani?query="
        return f"{base_url}{self.barcode}"
    
    def returning_packet(self):
        """Mark this packet as returning via the Packeta API."""
        response = packeta_client.get_return_routing(self.packet_id)
        
        self.return_routing = json.loads(response)
        self.state = self.STATE.RETURNING

        self.save()  # persist state change
    

class ZasilkovnaShipment(models.Model):
    created_at = models.DateTimeField(auto_now_add=True, editable=False)
    shipment_id = models.CharField(max_length=255, unique=True, help_text="ID zásilky v Packetě", editable=False)

    barcode = models.CharField(
        max_length=64, 
        help_text="Čárový kód zásilky v Packetě (format: )", 
        validators=[
            RegexValidator(r'D-***-XM-<id>', message="Neplatný formát čárového kódu.")
        ]
    )

    packets = models.ManyToManyField(ZasilkovnaPacket, related_name="shipments", help_text="Seznam zásilek v této zásilce (packet_id)")

    def save(self, *args, **kwargs):
        if not self.shipment_id:
            response = packeta_client.create_shipment(
                packet_ids=[packet.packet_id for packet in self.packets.all()]
            )
            self.shipment_id = response['shipment_id']
            self.barcode = response['barcode']

        return super().save(args, **kwargs)