import random
from django.db import models
from django.utils.text import slugify
from django.utils.translation import gettext_lazy as _


def get_default_region_pk():
    region = Region.get_default_region()
    return region.pk if region else None


class Region(models.Model):
    name = models.CharField(
        max_length=255,
        unique=True,
        verbose_name=_('Region Name'),
        help_text=_('Name of the geographical or administrative region (e.g. Middle East, Europe).')
    )
    slug = models.SlugField(
        max_length=255,
        unique=True,
        blank=True,
        null=True,
        allow_unicode=True,
        verbose_name=_('Slug / URL Identifier')
    )
    code = models.CharField(
        max_length=50,
        blank=True,
        null=True,
        verbose_name=_('Region Code'),
        help_text=_('Short code such as MENA, EU, NA, etc.')
    )
    description = models.TextField(
        blank=True,
        null=True,
        verbose_name=_('Description')
    )
    is_active = models.BooleanField(
        default=True,
        verbose_name=_('Is Active')
    )
    created_at = models.DateTimeField(
        auto_now_add=True,
        verbose_name=_('Created At')
    )
    updated_at = models.DateTimeField(
        auto_now=True,
        verbose_name=_('Updated At')
    )

    class Meta:
        ordering = ('name',)
        verbose_name = _('Region')
        verbose_name_plural = _('Regions')

    def __str__(self):
        return self.name

    def save(self, *args, **kwargs):
        if not self.slug:
            base_slug = slugify(self.name, allow_unicode=True) or f"region-{random.randint(1000, 9999)}"
            slug = base_slug
            counter = 1
            while Region.objects.filter(slug=slug).exclude(pk=self.pk).exists():
                slug = f"{base_slug}-{counter}"
                counter += 1
            self.slug = slug
        super().save(*args, **kwargs)

    @classmethod
    def get_default_region(cls):
        region = cls.objects.filter(name="Global / Other").first()
        if not region:
            region, _ = cls.objects.get_or_create(
                slug="global-other",
                defaults={
                    "name": "Global / Other",
                    "code": "GLB",
                    "description": "Default international / global region",
                    "is_active": True,
                }
            )
        return region