from django.db import models
from django.core.validators import MaxLengthValidator
from django.utils import timezone
from datetime import datetime, timedelta
from webtools import settings
from django.utils.translation import gettext_lazy as _


EXPIRE_CHOICES = (
    (0, _("Never expire")),
    (60, _("1 hour")),
    (60 * 24, _("1 day")),
    (60 * 24 * 7, _("1 week")),
    (60 * 24 * 7 * 30, _("1 month")),
    (60 * 24 * 7 * 365, _("1 year")),
)


class Language(models.Model):
    """Language object."""

    name = models.CharField(max_length=200, unique=True)
    slug = models.SlugField(max_length=200, unique=True)

    @classmethod
    def by_name(cls, name):
        language = cls.objects.filter(name__icontains=name).first()
        if not language:
            language = cls.objects.filter(
                name__iexact=settings.PASTE["default_language"]
            ).first()
        return language

    def __unicode__(self):
        """String representation."""
        return _(self.name)

    def __str__(self):
        return str(_(self.name))


class Paste(models.Model):
    """Paste object."""

    language = models.ForeignKey(
        Language, default=14, on_delete=models.SET_NULL, null=True
    )
    slug = models.SlugField(unique=True, editable=False)
    title = models.CharField(max_length=200, blank=True)
    content = models.TextField(
        validators=[MaxLengthValidator(settings.PASTE["max_characters"])]
    )
    size = models.IntegerField(default=0, editable=False)
    paste_time = models.DateTimeField(default=datetime.now, editable=False)
    lifetime = models.IntegerField(
        default=settings.PASTE["default_lifetime"], choices=EXPIRE_CHOICES
    )
    lifecount = models.IntegerField(default=0, blank=True)
    viewcount = models.IntegerField(default=0, editable=False)
    expired = models.BooleanField(default=False, editable=False)

    def compute_size(self):
        """Computes size."""
        self.size = len(self.content)

    def is_expired(self):
        """Return expiration status."""
        if self.expired or self.time_expired() or self.view_expired():
            return True
        return False

    def time_expired(self):
        """Check if paste lifetime is over."""
        if not self.lifetime or self.lifetime - self.get_age() > 0:
            return False
        self.mark_expired()
        return True

    def get_age(self):
        """Return age in minutes"""
        delta = timezone.now() - self.paste_time
        return divmod(delta.days * 86400 + delta.seconds, 60)[0]

    def expiration_time(self):
        """Return expiration time"""
        if not self.lifetime:
            return None
        delta = timedelta(minutes=self.lifetime)
        return self.paste_time + delta

    def mark_expired(self):
        """Mark paste expired."""
        self.expired = True
        self.save()

    def incr_viewcount(self):
        """Increment view counter."""
        self.viewcount = self.viewcount + 1
        self.save()

    def view_expired(self):
        """Check if paste view count is over."""
        if not self.lifecount:
            return False
        if self.lifecount <= self.viewcount:
            self.mark_expired()
            return True
        return False

    def __unicode__(self):
        """String representation."""
        return self.slug

    def __str__(self):
        excerpt = repr(self.content[:100]) + ("..." if len(self.content) > 100 else "")
        return "{} - {} - {}".format(self.slug, self.title, excerpt)