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