src/sponsors/models.py

   1 # This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later.
   2 # Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
   3 #
   4 import json
   5 import time
   6 from io import BytesIO
   7 from django.core.cache import cache
   8 from django.db import models
   9 from django.utils.translation import ugettext_lazy as _
  10 from django.template.loader import render_to_string
  11 from PIL import Image
  12
  13 from django.core.files.base import ContentFile
  14
  15 THUMB_WIDTH = 120
  16 THUMB_HEIGHT = 120
  17
  18
  19 class Sponsor(models.Model):
  20     name = models.CharField(_('name'), max_length=120)
  21     _description = models.CharField(_('description'), blank=True, max_length=255)
  22     logo = models.ImageField(_('logo'), upload_to='sponsorzy/sponsor/logo')
  23     url = models.URLField(_('url'), blank=True)
  24
  25     def __str__(self):
  26         return self.name
  27
  28     def description(self):
  29         if len(self._description):
  30             return self._description
  31         else:
  32             return self.name
  33
  34
  35 class SponsorPage(models.Model):
  36     name = models.CharField(_('name'), max_length=120)
  37     sponsors = models.TextField(_('sponsors'), default='{}')
  38     _html = models.TextField(blank=True, editable=False)
  39     sprite = models.ImageField(upload_to='sponsorzy/sprite', blank=True)
  40
  41     def get_sponsors_json(self):
  42         return json.loads(self.sponsors or '[]')
  43
  44     def populated_sponsors(self):
  45         result = []
  46         offset = 0
  47         for column in self.get_sponsors_json():
  48             result_group = {'name': column['name'], 'sponsors': []}
  49             sponsor_objects = Sponsor.objects.in_bulk(column['sponsors'])
  50             for sponsor_pk in column['sponsors']:
  51                 try:
  52                     result_group['sponsors'].append((offset, sponsor_objects[sponsor_pk]))
  53                     offset -= THUMB_HEIGHT
  54                 except KeyError:
  55                     pass
  56             if result_group['sponsors']:
  57                 result.append(result_group)
  58         return result
  59
  60     def render_sprite(self):
  61         sponsor_ids = []
  62         for column in self.get_sponsors_json():
  63             sponsor_ids.extend(column['sponsors'])
  64         sponsors = Sponsor.objects.in_bulk(sponsor_ids)
  65         sprite = Image.new('RGBA', (THUMB_WIDTH, len(sponsors) * THUMB_HEIGHT))
  66         for i, sponsor_id in enumerate(sponsor_ids):
  67             simg = Image.open(sponsors[sponsor_id].logo.path)
  68             if simg.size[0] > THUMB_WIDTH or simg.size[1] > THUMB_HEIGHT:
  69                 size = (
  70                     min(THUMB_WIDTH,
  71                         round(simg.size[0] * THUMB_HEIGHT / simg.size[1])),
  72                     min(THUMB_HEIGHT,
  73                         round(simg.size[1] * THUMB_WIDTH / simg.size[0]))
  74                 )
  75                 simg = simg.resize(size, Image.ANTIALIAS)
  76             sprite.paste(simg, (
  77                     round((THUMB_WIDTH - simg.size[0]) / 2),
  78                     round(i * THUMB_HEIGHT + (THUMB_HEIGHT - simg.size[1]) / 2),
  79                     ))
  80         imgstr = BytesIO()
  81         sprite.save(imgstr, 'png')
  82
  83         if self.sprite:
  84             self.sprite.delete(save=False)
  85         self.sprite.save('sponsorzy/sprite/%s-%d.png' % (
  86             self.name, time.time()), ContentFile(imgstr.getvalue()), save=False)
  87
  88     def html(self):
  89         return self._html
  90     html = property(fget=html)
  91
  92     def save(self, *args, **kwargs):
  93         self.render_sprite()
  94         self._html = render_to_string('sponsors/page.html', {
  95             'sponsors': self.populated_sponsors(),
  96             'page': self
  97         })
  98         ret = super(SponsorPage, self).save(*args, **kwargs)
  99         cache.delete('sponsor_page:' + self.name)
 100         return ret
 101
 102     def __str__(self):
 103         return self.name