from core.models.billable import CycleChoices
from core.models.products import ProductGroup

from django.db.models import Model, TextField, CharField, ManyToManyField, ForeignKey, CASCADE, PositiveIntegerField, DecimalField, OneToOneField

from importlib import import_module
from logging import getLogger

logger = getLogger(__name__)

class Service(Model):
    name = CharField(max_length=255)
    description = TextField(null=True, blank=True)
    handler_module = CharField(max_length=255, null=True, blank=True)
    product_groups = ManyToManyField(ProductGroup)

    @property
    def handler(self):
        if self.handler_module:
            try:
                handler_module = import_module(self.handler_module)
                return handler_module.ProductRouter(self.id)
            except Exception as e:
                logger.error(f"Could not load product handler {self.handler_module} for product {self.id}: {e}")
        return None

class ServicePlan(Model):
    service = OneToOneField(Service, on_delete=CASCADE)

    @classmethod
    def from_productplan(cls, productplan, service):
        plan = cls.objects.create(service=service)

        for item in productplan.serviceplanitem_set:
            ServicePlanItem.objects.create(plan=plan, cycle=item.cycle, count=item.count, cost=item.cost)

class ServicePlanItem(Model):    
    plan = ForeignKey(ServicePlan, on_delete=CASCADE)
    cycle = PositiveIntegerField(choices=CycleChoices.choices)
    count = PositiveIntegerField()
    cost = DecimalField(max_digits=30, decimal_places=2)