src/cover/models.py

   1 # This file is part of FNP-Redakcja, licensed under GNU Affero GPLv3 or later.
   2 # Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
   3 #
   4 from io import BytesIO
   5 from django.core.files.base import ContentFile
   6 from django.core.files.storage import FileSystemStorage
   7 from django.db import models
   8 from django.db.models.signals import post_save
   9 from django.dispatch import receiver
  10 from django.urls import reverse
  11 from django.utils.translation import gettext_lazy as _
  12 from django.contrib.sites.models import Site
  13 from PIL import Image as PILImage
  14 from cover.utils import URLOpener
  15
  16
  17 class OverwriteStorage(FileSystemStorage):
  18
  19     def get_available_name(self, name, max_length=None):
  20         self.delete(name)
  21         return name
  22
  23
  24 class Image(models.Model):
  25     title = models.CharField(max_length=255, verbose_name=_('title'))
  26     author = models.CharField(max_length=255, verbose_name=_('author'))
  27     license_name = models.CharField(max_length=255, verbose_name=_('license name'))
  28     license_url = models.URLField(max_length=255, blank=True, verbose_name=_('license URL'))
  29     source_url = models.URLField(verbose_name=_('source URL'), null=True, blank=True)
  30     download_url = models.URLField(max_length=4096, unique=True, verbose_name=_('image download URL'), null=True, blank=True)
  31     file = models.ImageField(
  32         upload_to='cover/image',
  33         storage=OverwriteStorage(),
  34         verbose_name=_('file')
  35     )
  36     use_file = models.ImageField(
  37         upload_to='cover/use',
  38         storage=OverwriteStorage(),
  39         editable=True,
  40         verbose_name=_('file for use')
  41     )
  42     cut_top = models.IntegerField(default=0, )
  43     cut_bottom = models.IntegerField(default=0)
  44     cut_left = models.IntegerField(default=0)
  45     cut_right = models.IntegerField(default=0)
  46
  47     class Meta:
  48         verbose_name = _('cover image')
  49         verbose_name_plural = _('cover images')
  50
  51     def __str__(self):
  52         return u"%s - %s" % (self.author, self.title)
  53
  54     def save(self, **kwargs):
  55         super().save(**kwargs)
  56         img = self.file
  57         if self.cut_top or self.cut_bottom or self.cut_left or self.cut_right:
  58             img = PILImage.open(img)
  59             img = img.crop((
  60                 self.cut_left,
  61                 self.cut_top,
  62                 img.size[0] - self.cut_right,
  63                 img.size[1] - self.cut_bottom,
  64             ))
  65             buffer = BytesIO()
  66             img.save(
  67                 buffer,
  68                 format='JPEG',
  69             )
  70             img = ContentFile(buffer.getvalue())
  71         self.use_file.save(
  72             "%d.jpg" % self.pk,
  73             img,
  74             save=False
  75         )
  76         super().save(update_fields=['use_file'])
  77
  78     def get_absolute_url(self):
  79         return reverse('cover_image', args=[self.id])
  80
  81     def get_full_url(self):
  82         return "http://%s%s" % (Site.objects.get_current().domain, self.get_absolute_url())
  83
  84
  85 @receiver(post_save, sender=Image)
  86 def download_image(sender, instance, **kwargs):
  87     if instance.pk and not instance.file:
  88         t = URLOpener().open(instance.download_url).read()
  89         instance.file.save("%d.jpg" % instance.pk, ContentFile(t))