from django.db import models
from django.utils import timezone

from core.models.directories import directory_default


class Consumable(models.Model):
    consumable_type = models.ForeignKey(
        'core.Directory', on_delete=models.PROTECT,
        limit_choices_to={'directory_type__code': 'consumable_type', 'is_active': True},
        related_name='consumables_by_type', verbose_name='Тип',
        default=directory_default('consumable_type', 'cartridge'),
    )
    brand           = models.CharField('Производитель', max_length=100, blank=True)
    model_number    = models.CharField('Модель / артикул', max_length=100)
    color = models.ForeignKey(
        'core.Directory', on_delete=models.PROTECT,
        limit_choices_to={'directory_type__code': 'consumable_color', 'is_active': True},
        related_name='consumables_by_color', verbose_name='Цвет',
        default=directory_default('consumable_color', 'black'),
    )
    status = models.ForeignKey(
        'core.Directory', on_delete=models.PROTECT,
        limit_choices_to={'directory_type__code': 'consumable_status', 'is_active': True},
        related_name='consumables_by_status', verbose_name='Статус',
        default=directory_default('consumable_status', 'in_stock'),
    )

    equipment = models.ForeignKey(
        'it_manager.Equipment', on_delete=models.SET_NULL,
        null=True, blank=True,
        related_name='consumables', verbose_name='Устройство',
        limit_choices_to={'equipment_model__equipment_type__code': 'printer'},
    )
    location = models.ForeignKey(
        'locations.Location', on_delete=models.SET_NULL,
        null=True, blank=True,
        related_name='consumables', verbose_name='Локация хранения',
    )

    page_yield      = models.PositiveIntegerField('Ресурс (страниц)', null=True, blank=True)
    purchase_date   = models.DateField('Дата покупки', null=True, blank=True)
    installed_date  = models.DateField('Дата установки', null=True, blank=True)
    replaced_date   = models.DateField('Дата замены', null=True, blank=True)

    notes      = models.TextField('Примечания', blank=True)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        verbose_name        = 'Расходник'
        verbose_name_plural = 'Расходники'
        ordering = ['equipment', 'consumable_type__name', 'color__name']

    def __str__(self):
        parts = [self.consumable_type.name]
        if self.brand:
            parts.append(self.brand)
        parts.append(self.model_number)
        if self.color.code != 'na':
            parts.append(f'({self.color.name})')
        return ' '.join(parts)

    @property
    def is_low(self):
        """Нужно заказывать: закончился или заказан."""
        return self.status.code in ('empty', 'ordered')