apps/lesmianator/models.py

   1 # -*- coding: utf-8 -*-
   2 # This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later.
   3 # Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
   4 #
   5 import cPickle
   6 from datetime import datetime
   7 from random import randint
   8 from StringIO import StringIO
   9
  10 from django.core.files.base import ContentFile
  11 from django.db import models
  12 from django.db.models import permalink
  13 from django.utils.translation import ugettext_lazy as _
  14 from django.core.urlresolvers import reverse
  15 from django.db.models.signals import m2m_changed
  16 from django.contrib.auth.models import User
  17 from django.contrib.contenttypes.models import ContentType
  18 from django.contrib.contenttypes import generic
  19 from django.conf import settings
  20
  21 from catalogue.fields import JSONField
  22 from catalogue.models import Book, Tag
  23
  24
  25 class Poem(models.Model):
  26     slug = models.SlugField(_('slug'), max_length=120, db_index=True)
  27     text = models.TextField(_('text'))
  28     created_by = models.ForeignKey(User, null=True)
  29     created_from = JSONField(_('extra information'), null=True, blank=True)
  30     created_at = models.DateTimeField(_('creation date'), auto_now_add=True, editable=False)
  31     seen_at = models.DateTimeField(_('last view date'), auto_now_add=True, editable=False)
  32     view_count = models.IntegerField(_('view count'), default=1)
  33
  34     try:
  35         f = open(settings.LESMIANATOR_PICKLE)
  36         global_dictionary = cPickle.load(f)
  37         f.close()
  38     except:
  39         global_dictionary = {}
  40
  41     def visit(self):
  42         self.view_count += 1
  43         self.seen_at = datetime.now()
  44         self.save()
  45
  46     def __unicode__(self):
  47         return "%s (%s...)" % (self.slug, self.text[:20])
  48
  49     @staticmethod
  50     def choose_letter(word, continuations):
  51         if word not in continuations:
  52             return u'\n'
  53
  54         choices = sum((continuations[word][letter]
  55                        for letter in continuations[word]))
  56         r = randint(0, choices - 1)
  57
  58         for letter in continuations[word]:
  59             r -= continuations[word][letter]
  60             if r < 0:
  61                 return letter
  62
  63     @classmethod
  64     def write(cls, continuations=None, length=3, min_lines=2, maxlen=1000):
  65         if continuations is None:
  66             continuations = cls.global_dictionary
  67         if not continuations:
  68             return ''
  69
  70         letters = []
  71         word = u''
  72
  73         finished_stanza_verses = 0
  74         current_stanza_verses = 0
  75         verse_start = True
  76
  77         char_count = 0
  78
  79         # do `min_lines' non-empty verses and then stop,
  80         # but let Lesmianator finish his last stanza.
  81         while finished_stanza_verses < min_lines and char_count < maxlen:
  82             letter = cls.choose_letter(word, continuations)
  83             letters.append(letter)
  84             word = word[-length + 1:] + letter
  85             char_count += 1
  86
  87             if letter == u'\n':
  88                 if verse_start:
  89                     finished_stanza_verses += current_stanza_verses
  90                     current_stanza_verses = 0
  91                 else:
  92                     current_stanza_verses += 1
  93                     verse_start = True
  94             else:
  95                 verse_start = False
  96
  97         return ''.join(letters).strip()
  98
  99     def get_absolute_url(self):
 100         return reverse('get_poem', kwargs={'poem': self.slug})
 101
 102
 103 class Continuations(models.Model):
 104     pickle = models.FileField(_('Continuations file'), upload_to='lesmianator')
 105     content_type = models.ForeignKey(ContentType)
 106     object_id = models.PositiveIntegerField()
 107     content_object = generic.GenericForeignKey('content_type', 'object_id')
 108
 109     class Meta:
 110         unique_together = (('content_type', 'object_id'), )
 111
 112     def __unicode__(self):
 113         return "Continuations for: %s" % unicode(self.content_object)
 114
 115     @staticmethod
 116     def join_conts(a, b):
 117         for pre in b:
 118             a.setdefault(pre, {})
 119             for post in b[pre]:
 120                 a[pre].setdefault(post, 0)
 121                 a[pre][post] += b[pre][post]
 122         return a
 123
 124     @classmethod
 125     def for_book(cls, book, length=3):
 126         # count from this book only
 127         output = StringIO()
 128         wldoc = book.wldocument(parse_dublincore=False)
 129         output = wldoc.as_text(('raw-text',)).get_string()
 130         del wldoc
 131
 132         conts = {}
 133         last_word = ''
 134         for letter in output.decode('utf-8').strip().lower():
 135             mydict = conts.setdefault(last_word, {})
 136             mydict.setdefault(letter, 0)
 137             mydict[letter] += 1
 138             last_word = last_word[-length+1:] + letter
 139         # add children
 140         return reduce(cls.join_conts,
 141                       (cls.get(child) for child in book.children.all()),
 142                       conts)
 143
 144     @classmethod
 145     def for_set(cls, tag):
 146         # book contains its descendants, we don't want them twice
 147         books = Book.tagged.with_any((tag,))
 148         l_tags = Tag.objects.filter(category='book', slug__in=[book.book_tag_slug() for book in books])
 149         descendants_keys = [book.pk for book in Book.tagged.with_any(l_tags)]
 150         if descendants_keys:
 151             books = books.exclude(pk__in=descendants_keys)
 152
 153         cont_tabs = (cls.get(b) for b in books)
 154         return reduce(cls.join_conts, cont_tabs)
 155
 156     @classmethod
 157     def get(cls, sth):
 158         object_type = ContentType.objects.get_for_model(sth)
 159         should_keys = set([sth.id])
 160         if isinstance(sth, Tag):
 161             should_keys = set(b.pk for b in Book.tagged.with_any((sth,)))
 162         try:
 163             obj = cls.objects.get(content_type=object_type, object_id=sth.id)
 164             if not obj.pickle:
 165                 raise cls.DoesNotExist
 166             f = open(obj.pickle.path)
 167             keys, conts = cPickle.load(f)
 168             f.close()
 169             if set(keys) != should_keys:
 170                 raise cls.DoesNotExist
 171             return conts
 172         except cls.DoesNotExist:
 173             if isinstance(sth, Book):
 174                 conts = cls.for_book(sth)
 175             elif isinstance(sth, Tag):
 176                 conts = cls.for_set(sth)
 177             else:
 178                 raise NotImplemented('Lesmianator continuations: only Book and Tag supported')
 179
 180             c, created = cls.objects.get_or_create(content_type=object_type, object_id=sth.id)
 181             c.pickle.save(sth.slug+'.p', ContentFile(cPickle.dumps((should_keys, conts))))
 182             c.save()
 183             return conts
 184
 185