from uuid import uuid4
from django.db import models

from metadata.models import Company, Tag
from roster.models import RollingStock


class Consist(models.Model):
    uuid = models.UUIDField(
        primary_key=True, default=uuid4,
        editable=False)
    identifier = models.CharField(max_length=128, unique=False)
    tags = models.ManyToManyField(
        Tag,
        related_name='consist',
        blank=True)
    address = models.SmallIntegerField(default=None, null=True, blank=True)
    company = models.ForeignKey(
        Company, on_delete=models.CASCADE,
        null=True, blank=True)
    epoch = models.CharField(max_length=32, blank=True)
    notes = models.TextField(blank=True)
    creation_time = models.DateTimeField(auto_now_add=True)
    updated_time = models.DateTimeField(auto_now=True)

    def __str__(self):
        return "{0}".format(self.identifier)


class ConsistItem(models.Model):
    consist = models.ForeignKey(
        Consist, on_delete=models.CASCADE)
    rolling_stock = models.ForeignKey(
        RollingStock, on_delete=models.CASCADE)
    order = models.PositiveIntegerField(default=0, blank=False, null=False)

    class Meta(object):
        ordering = ['order']

    def __str__(self):
        return "{0}".format(self.rolling_stock.identifier)

    # def type(self):
    #     return self.rolling_stock.type

    def address(self):
        return self.rolling_stock.address

    def company(self):
        return self.rolling_stock.company

    def epoch(self):
        return self.rolling_stock.epoch