py2.6: no set literals
[wolnelektury.git] / apps / catalogue / views.py
index cf1461f..fc27e02 100644 (file)
 # This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later.
 # Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
 #
-import tempfile
-import zipfile
-import sys
-import pprint
-import traceback
 import re
+import itertools
 
 from django.conf import settings
 from django.template import RequestContext
-from django.shortcuts import render_to_response, get_object_or_404
-from django.http import HttpResponse, HttpResponseRedirect, Http404
+from django.shortcuts import render_to_response, get_object_or_404, redirect
+from django.http import HttpResponse, HttpResponseRedirect, Http404, HttpResponsePermanentRedirect
 from django.core.urlresolvers import reverse
 from django.db.models import Q
 from django.contrib.auth.decorators import login_required, user_passes_test
 from django.utils.datastructures import SortedDict
-from django.views.decorators.http import require_POST
-from django.contrib import auth
-from django.contrib.auth.forms import UserCreationForm, AuthenticationForm
-from django.utils import simplejson
-from django.utils.functional import Promise
-from django.utils.encoding import force_unicode
 from django.utils.http import urlquote_plus
-from django.views.decorators import cache
-from django.utils.translation import ugettext as _
+from django.utils import translation
+from django.utils.translation import ugettext as _, ugettext_lazy
+from django.views.decorators.cache import never_cache
+
+from ajaxable.utils import JSONResponse, AjaxableFormView
 
 from catalogue import models
 from catalogue import forms
-from catalogue.utils import split_tags
-from newtagging import views as newtagging_views
-
+from catalogue.utils import split_tags, MultiQuerySet
+from pdcounter import models as pdcounter_models
+from pdcounter import views as pdcounter_views
+from suggest.forms import PublishingSuggestForm
+from picture.models import Picture
 
 staff_required = user_passes_test(lambda user: user.is_staff)
 
 
-class LazyEncoder(simplejson.JSONEncoder):
-    def default(self, obj):
-        if isinstance(obj, Promise):
-            return force_unicode(obj)
-        return obj
-
-
-def main_page(request):    
-    if request.user.is_authenticated():
-        shelves = models.Tag.objects.filter(category='set', user=request.user)
-        new_set_form = forms.NewSetForm()
-    extra_where = "NOT catalogue_tag.category = 'set'"
-    tags = models.Tag.objects.usage_for_model(models.Book, counts=True, extra={'where': [extra_where]})
-    fragment_tags = models.Tag.objects.usage_for_model(models.Fragment, counts=True,
-        extra={'where': ["catalogue_tag.category = 'theme'"] + [extra_where]})
+def catalogue(request):
+    tags = models.Tag.objects.exclude(
+        category__in=('set', 'book')).exclude(book_count=0)
+    tags = list(tags)
+    for tag in tags:
+        tag.count = tag.book_count
     categories = split_tags(tags)
-    
-    form = forms.SearchForm()
-    return render_to_response('catalogue/main_page.html', locals(),
+    fragment_tags = categories.get('theme', [])
+
+    return render_to_response('catalogue/catalogue.html', locals(),
         context_instance=RequestContext(request))
 
 
-def book_list(request):
-    books = models.Book.objects.all()
-    form = forms.SearchForm()
-    
-    books_by_first_letter = SortedDict()
-    for book in books:
-        books_by_first_letter.setdefault(book.title[0], []).append(book)
-    
-    return render_to_response('catalogue/book_list.html', locals(),
+def book_list(request, filter=None, template_name='catalogue/book_list.html',
+        context=None):
+    """ generates a listing of all books, optionally filtered with a test function """
+
+    books_by_author, orphans, books_by_parent = models.Book.book_list(filter)
+    books_nav = SortedDict()
+    for tag in books_by_author:
+        if books_by_author[tag]:
+            books_nav.setdefault(tag.sort_key[0], []).append(tag)
+
+    return render_to_response(template_name, locals(),
         context_instance=RequestContext(request))
 
 
+def audiobook_list(request):
+    return book_list(request, Q(media__type='mp3') | Q(media__type='ogg'),
+                     template_name='catalogue/audiobook_list.html')
+
+
+def daisy_list(request):
+    return book_list(request, Q(media__type='daisy'),
+                     template_name='catalogue/daisy_list.html')
+
+
+def collection(request, slug):
+    coll = get_object_or_404(models.Collection, slug=slug)
+    slugs = coll.book_slugs.split()
+    # allow URIs
+    slugs = [slug.rstrip('/').rsplit('/', 1)[-1] if '/' in slug else slug
+                for slug in slugs]
+    return book_list(request, Q(slug__in=slugs),
+                     template_name='catalogue/collection.html',
+                     context={'collection': coll})
+
+
+def differentiate_tags(request, tags, ambiguous_slugs):
+    beginning = '/'.join(tag.url_chunk for tag in tags)
+    unparsed = '/'.join(ambiguous_slugs[1:])
+    options = []
+    for tag in models.Tag.objects.exclude(category='book').filter(slug=ambiguous_slugs[0]):
+        options.append({
+            'url_args': '/'.join((beginning, tag.url_chunk, unparsed)).strip('/'),
+            'tags': [tag]
+        })
+    return render_to_response('catalogue/differentiate_tags.html',
+                {'tags': tags, 'options': options, 'unparsed': ambiguous_slugs[1:]},
+                context_instance=RequestContext(request))
+
+
+@never_cache
 def tagged_object_list(request, tags=''):
-    # Prevent DoS attacks on our database
-    if len(tags.split('/')) > 6:
-        raise Http404
-        
     try:
         tags = models.Tag.get_tag_list(tags)
     except models.Tag.DoesNotExist:
-        raise Http404
-    
+        chunks = tags.split('/')
+        if len(chunks) == 2 and chunks[0] == 'autor':
+            return pdcounter_views.author_detail(request, chunks[1])
+        else:
+            raise Http404
+    except models.Tag.MultipleObjectsReturned, e:
+        return differentiate_tags(request, e.tags, e.ambiguous_slugs)
+    except models.Tag.UrlDeprecationWarning, e:
+        return HttpResponsePermanentRedirect(reverse('tagged_object_list', args=['/'.join(tag.url_chunk for tag in e.tags)]))
+
+    try:
+        if len(tags) > settings.MAX_TAG_LIST:
+            raise Http404
+    except AttributeError:
+        pass
+
     if len([tag for tag in tags if tag.category == 'book']):
         raise Http404
-    
-    model = models.Book
-    shelf = [tag for tag in tags if tag.category == 'set']
-    shelf_is_set = (len(tags) == 1 and tags[0].category == 'set')
-    theme_is_set = len([tag for tag in tags if tag.category == 'theme']) > 0
+
+    theme_is_set = [tag for tag in tags if tag.category == 'theme']
+    shelf_is_set = [tag for tag in tags if tag.category == 'set']
+    only_shelf = shelf_is_set and len(tags) == 1
+    only_my_shelf = only_shelf and request.user.is_authenticated() and request.user == tags[0].user
+
+    objects = only_author = None
+    categories = {}
+
     if theme_is_set:
-        model = models.Fragment
-    only_author = len(tags) == 1 and tags[0].category == 'author'
-    pd_counter = only_author and tags[0].goes_to_pd()
-
-    user_is_owner = (len(shelf) and request.user.is_authenticated() and request.user == shelf[0].user)
-    
-    extra_where = "catalogue_tag.category NOT IN ('set', 'book')"
-    related_tags = models.Tag.objects.related_for_model(tags, model, counts=True, extra={'where': [extra_where]})
-    categories = split_tags(related_tags)
-
-    if not (theme_is_set or shelf_is_set):
-        model=models.Book.objects.filter(parent=None)
-    
-    return newtagging_views.tagged_object_list(
-        request,
-        tag_model=models.Tag,
-        queryset_or_model=model,
-        tags=tags,
-        template_name='catalogue/tagged_object_list.html',
-        extra_context = {
+        shelf_tags = [tag for tag in tags if tag.category == 'set']
+        fragment_tags = [tag for tag in tags if tag.category != 'set']
+        fragments = models.Fragment.tagged.with_all(fragment_tags)
+
+        if shelf_tags:
+            books = models.Book.tagged.with_all(shelf_tags).order_by()
+            l_tags = models.Tag.objects.filter(category='book',
+                slug__in=[book.book_tag_slug() for book in books.iterator()])
+            fragments = models.Fragment.tagged.with_any(l_tags, fragments)
+
+        # newtagging goes crazy if we just try:
+        #related_tags = models.Tag.objects.usage_for_queryset(fragments, counts=True,
+        #                    extra={'where': ["catalogue_tag.category != 'book'"]})
+        fragment_keys = [fragment.pk for fragment in fragments.iterator()]
+        if fragment_keys:
+            related_tags = models.Fragment.tags.usage(counts=True,
+                                filters={'pk__in': fragment_keys},
+                                extra={'where': ["catalogue_tag.category != 'book'"]})
+            related_tags = (tag for tag in related_tags if tag not in fragment_tags)
+            categories = split_tags(related_tags)
+
+            objects = fragments
+    else:
+        if shelf_is_set:
+            objects = models.Book.tagged.with_all(tags)
+        else:
+            objects = models.Book.tagged_top_level(tags)
+
+        # get related tags from `tag_counter` and `theme_counter`
+        related_counts = {}
+        tags_pks = [tag.pk for tag in tags]
+        for book in objects.iterator():
+            for tag_pk, value in itertools.chain(book.tag_counter.iteritems(), book.theme_counter.iteritems()):
+                if tag_pk in tags_pks:
+                    continue
+                related_counts[tag_pk] = related_counts.get(tag_pk, 0) + value
+        related_tags = models.Tag.objects.filter(pk__in=related_counts.keys())
+        related_tags = [tag for tag in related_tags if tag not in tags]
+        for tag in related_tags:
+            tag.count = related_counts[tag.pk]
+
+        categories = split_tags(related_tags)
+        del related_tags
+
+    if not objects:
+        only_author = len(tags) == 1 and tags[0].category == 'author'
+        objects = models.Book.objects.none()
+
+    # Add pictures
+    objects = MultiQuerySet(Picture.tagged.with_all(tags), objects)
+
+    return render_to_response('catalogue/tagged_object_list.html',
+        {
+            'object_list': objects,
             'categories': categories,
-            'shelf_is_set': shelf_is_set,
+            'only_shelf': only_shelf,
             'only_author': only_author,
-            'pd_counter': pd_counter,
-            'user_is_owner': user_is_owner,
+            'only_my_shelf': only_my_shelf,
             'formats_form': forms.DownloadFormatsForm(),
+            'tags': tags,
+            'theme_is_set': theme_is_set,
         },
-    )
+        context_instance=RequestContext(request))
+
 
+def book_fragments(request, slug, theme_slug):
+    book = get_object_or_404(models.Book, slug=slug)
 
-def book_fragments(request, book_slug, theme_slug):
-    book = get_object_or_404(models.Book, slug=book_slug)
-    book_tag = get_object_or_404(models.Tag, slug='l-' + book_slug)
-    theme = get_object_or_404(models.Tag, slug=theme_slug)
+    book_tag = book.book_tag()
+    theme = get_object_or_404(models.Tag, slug=theme_slug, category='theme')
     fragments = models.Fragment.tagged.with_all([book_tag, theme])
-    
-    form = forms.SearchForm()
+
     return render_to_response('catalogue/book_fragments.html', locals(),
         context_instance=RequestContext(request))
 
 
+@never_cache
 def book_detail(request, slug):
     try:
         book = models.Book.objects.get(slug=slug)
     except models.Book.DoesNotExist:
-        return book_stub_detail(request, slug)
+        return pdcounter_views.book_stub_detail(request, slug)
 
-    book_tag = get_object_or_404(models.Tag, slug = 'l-' + slug)
-    tags = list(book.tags.filter(~Q(category='set')))
-    categories = split_tags(tags)
-    book_children = book.children.all().order_by('parent_number')
-    extra_where = "catalogue_tag.category = 'theme'"
-    book_themes = models.Tag.objects.related_for_model(book_tag, models.Fragment, counts=True, extra={'where': [extra_where]})
-    extra_info = book.get_extra_info_value()
-    
-    form = forms.SearchForm()
+    book_children = book.children.all().order_by('parent_number', 'sort_key')
     return render_to_response('catalogue/book_detail.html', locals(),
         context_instance=RequestContext(request))
 
 
-def book_stub_detail(request, slug):
-    book = get_object_or_404(models.BookStub, slug=slug)
-    pd_counter = book.pd
-    form = forms.SearchForm()
-    
-    return render_to_response('catalogue/book_stub_detail.html', locals(),
+def player(request, slug):
+    book = get_object_or_404(models.Book, slug=slug)
+    if not book.has_media('mp3'):
+        raise Http404
+
+    ogg_files = {}
+    for m in book.media.filter(type='ogg').order_by().iterator():
+        ogg_files[m.name] = m
+
+    audiobooks = []
+    have_oggs = True
+    projects = set()
+    for mp3 in book.media.filter(type='mp3').iterator():
+        # ogg files are always from the same project
+        meta = mp3.extra_info
+        project = meta.get('project')
+        if not project:
+            # temporary fallback
+            project = u'CzytamySłuchając'
+
+        projects.add((project, meta.get('funded_by', '')))
+
+        media = {'mp3': mp3}
+
+        ogg = ogg_files.get(mp3.name)
+        if ogg:
+            media['ogg'] = ogg
+        else:
+            have_oggs = False
+        audiobooks.append(media)
+
+    projects = sorted(projects)
+
+    extra_info = book.extra_info
+
+    return render_to_response('catalogue/player.html', locals(),
         context_instance=RequestContext(request))
-    
+
 
 def book_text(request, slug):
     book = get_object_or_404(models.Book, slug=slug)
+
+    if not book.has_html_file():
+        raise Http404
     book_themes = {}
-    for fragment in book.fragments.all():
-        for theme in fragment.tags.filter(category='theme'):
+    for fragment in book.fragments.all().iterator():
+        for theme in fragment.tags.filter(category='theme').iterator():
             book_themes.setdefault(theme, []).append(fragment)
-    
+
     book_themes = book_themes.items()
     book_themes.sort(key=lambda s: s[0].sort_key)
+    related = book.related_info()
     return render_to_response('catalogue/book_text.html', locals(),
         context_instance=RequestContext(request))
 
@@ -176,105 +276,175 @@ def book_text(request, slug):
 
 def _no_diacritics_regexp(query):
     """ returns a regexp for searching for a query without diacritics
-    
+
     should be locale-aware """
-    names = {'a':u'ą', 'c':u'ć', 'e':u'ę', 'l': u'ł', 'n':u'ń', 'o':u'ó', 's':u'ś', 'z':u'ź|ż'}
+    names = {
+        u'a':u'aąĄ', u'c':u'cćĆ', u'e':u'eęĘ', u'l': u'lłŁ', u'n':u'nńŃ', u'o':u'oóÓ', u's':u'sśŚ', u'z':u'zźżŹŻ',
+        u'ą':u'ąĄ', u'ć':u'ćĆ', u'ę':u'ęĘ', u'ł': u'łŁ', u'ń':u'ńŃ', u'ó':u'óÓ', u'ś':u'śŚ', u'ź':u'źŹ', u'ż':u'żŻ'
+        }
     def repl(m):
         l = m.group()
-        return "(%s|%s)" % (l, names[l])
-    return re.sub('[%s]'%(''.join(names.keys())), repl, query)
+        return u"(%s)" % '|'.join(names[l])
+    return re.sub(u'[%s]' % (u''.join(names.keys())), repl, query)
+
+def unicode_re_escape(query):
+    """ Unicode-friendly version of re.escape """
+    return re.sub('(?u)(\W)', r'\\\1', query)
 
 def _word_starts_with(name, prefix):
     """returns a Q object getting models having `name` contain a word
     starting with `prefix`
+
+    We define word characters as alphanumeric and underscore, like in JS.
+
+    Works for MySQL, PostgreSQL, Oracle.
+    For SQLite, _sqlite* version is substituted for this.
     """
     kwargs = {}
-    if settings.DATABASE_ENGINE in ('mysql', 'postgresql_psycopg2', 'postgresql'):
-        prefix = _no_diacritics_regexp(re.escape(prefix))
-        # we could use a [[:<:]] (word start), 
-        # but we want both `xy` and `(xy` to catch `(xyz)`
-        kwargs['%s__iregex' % name] = u"(^|[^[:alpha:]])%s" % prefix
-    else:
-        # don't know how to do a generic regex
-        # checking for simple icontain instead
-        kwargs['%s__icontains' % name] = prefix
+
+    prefix = _no_diacritics_regexp(unicode_re_escape(prefix))
+    # can't use [[:<:]] (word start),
+    # but we want both `xy` and `(xy` to catch `(xyz)`
+    kwargs['%s__iregex' % name] = u"(^|[^[:alnum:]_])%s" % prefix
+
     return Q(**kwargs)
 
 
-def _tags_exact_matches(prefix, user):
-    book_stubs = models.BookStub.objects.filter(title__iexact = prefix)
-    books = models.Book.objects.filter(title__iexact = prefix)
-    book_stubs = filter(lambda x: x not in books, book_stubs)
-    tags = models.Tag.objects.filter(name__iexact = prefix)
-    if user.is_authenticated():
-        tags = tags.filter(~Q(category='book') & (~Q(category='set') | Q(user=user)))
-    else:
-        tags = tags.filter(~Q(category='book') & ~Q(category='set'))
+def _word_starts_with_regexp(prefix):
+    prefix = _no_diacritics_regexp(unicode_re_escape(prefix))
+    return ur"(^|(?<=[^\wąćęłńóśźżĄĆĘŁŃÓŚŹŻ]))%s" % prefix
+
+
+def _sqlite_word_starts_with(name, prefix):
+    """ version of _word_starts_with for SQLite
+
+    SQLite in Django uses Python re module
+    """
+    kwargs = {}
+    kwargs['%s__iregex' % name] = _word_starts_with_regexp(prefix)
+    return Q(**kwargs)
 
-    return list(books) + list(tags) + list(book_stubs)
 
+if hasattr(settings, 'DATABASES'):
+    if settings.DATABASES['default']['ENGINE'] == 'django.db.backends.sqlite3':
+        _word_starts_with = _sqlite_word_starts_with
+elif settings.DATABASE_ENGINE == 'sqlite3':
+    _word_starts_with = _sqlite_word_starts_with
+
+
+class App():
+    def __init__(self, name, view):
+        self.name = name
+        self._view = view
+        self.lower = name.lower()
+        self.category = 'application'
+    def view(self):
+        return reverse(*self._view)
+
+_apps = (
+    App(u'Leśmianator', (u'lesmianator', )),
+    )
+
+
+def _tags_starting_with(prefix, user=None):
+    prefix = prefix.lower()
+    # PD counter
+    book_stubs = pdcounter_models.BookStub.objects.filter(_word_starts_with('title', prefix))
+    authors = pdcounter_models.Author.objects.filter(_word_starts_with('name', prefix))
 
-def _tags_starting_with(prefix, user):
-    book_stubs = models.BookStub.objects.filter(_word_starts_with('title', prefix))
     books = models.Book.objects.filter(_word_starts_with('title', prefix))
-    book_stubs = filter(lambda x: x not in books, book_stubs)
     tags = models.Tag.objects.filter(_word_starts_with('name', prefix))
-    if user.is_authenticated():
+    if user and user.is_authenticated():
         tags = tags.filter(~Q(category='book') & (~Q(category='set') | Q(user=user)))
     else:
         tags = tags.filter(~Q(category='book') & ~Q(category='set'))
 
-    return list(books) + list(tags) + list(book_stubs)
-        
+    prefix_regexp = re.compile(_word_starts_with_regexp(prefix))
+    return list(books) + list(tags) + [app for app in _apps if prefix_regexp.search(app.lower)] + list(book_stubs) + list(authors)
 
 
 def _get_result_link(match, tag_list):
-    if isinstance(match, models.Book) or isinstance(match, models.BookStub):
-        return match.get_absolute_url()
-    else:
-        return reverse('catalogue.views.tagged_object_list', 
-            kwargs={'tags': '/'.join(tag.slug for tag in tag_list + [match])}
+    if isinstance(match, models.Tag):
+        return reverse('catalogue.views.tagged_object_list',
+            kwargs={'tags': '/'.join(tag.url_chunk for tag in tag_list + [match])}
         )
+    elif isinstance(match, App):
+        return match.view()
+    else:
+        return match.get_absolute_url()
+
 
 def _get_result_type(match):
-    if isinstance(match, models.Book) or isinstance(match, models.BookStub):
+    if isinstance(match, models.Book) or isinstance(match, pdcounter_models.BookStub):
         type = 'book'
     else:
         type = match.category
-    return dict(models.TAG_CATEGORIES)[type]
-    
+    return type
+
+
+def books_starting_with(prefix):
+    prefix = prefix.lower()
+    return models.Book.objects.filter(_word_starts_with('title', prefix))
+
+
+def find_best_matches(query, user=None):
+    """ Finds a models.Book, Tag, models.BookStub or Author best matching a query.
+
+    Returns a with:
+      - zero elements when nothing is found,
+      - one element when a best result is found,
+      - more then one element on multiple exact matches
+
+    Raises a ValueError on too short a query.
+    """
+
+    query = query.lower()
+    if len(query) < 2:
+        raise ValueError("query must have at least two characters")
+
+    result = tuple(_tags_starting_with(query, user))
+    # remove pdcounter stuff
+    book_titles = set(match.pretty_title().lower() for match in result
+                      if isinstance(match, models.Book))
+    authors = set(match.name.lower() for match in result
+                  if isinstance(match, models.Tag) and match.category=='author')
+    result = tuple(res for res in result if not (
+                 (isinstance(res, pdcounter_models.BookStub) and res.pretty_title().lower() in book_titles)
+                 or (isinstance(res, pdcounter_models.Author) and res.name.lower() in authors)
+             ))
+
+    exact_matches = tuple(res for res in result if res.name.lower() == query)
+    if exact_matches:
+        return exact_matches
+    else:
+        return tuple(result)[:1]
 
 
 def search(request):
     tags = request.GET.get('tags', '')
     prefix = request.GET.get('q', '')
-    
+
     try:
         tag_list = models.Tag.get_tag_list(tags)
     except:
         tag_list = []
 
-    # Prefix must have at least 2 characters
-    if len(prefix) < 2:
+    try:
+        result = find_best_matches(prefix, request.user)
+    except ValueError:
         return render_to_response('catalogue/search_too_short.html', {'tags':tag_list, 'prefix':prefix},
             context_instance=RequestContext(request))
-    
-    result = _tags_exact_matches(prefix, request.user)
-    
-    if len(result) > 1:
-        # multiple exact matches
-        return render_to_response('catalogue/search_multiple_hits.html', 
+
+    if len(result) == 1:
+        return HttpResponseRedirect(_get_result_link(result[0], tag_list))
+    elif len(result) > 1:
+        return render_to_response('catalogue/search_multiple_hits.html',
             {'tags':tag_list, 'prefix':prefix, 'results':((x, _get_result_link(x, tag_list), _get_result_type(x)) for x in result)},
             context_instance=RequestContext(request))
-    
-    if not result:
-        # no exact matches
-        result = _tags_starting_with(prefix, request.user)
-    
-    if result:
-        return HttpResponseRedirect(_get_result_link(result[0], tag_list))
     else:
-        return render_to_response('catalogue/search_no_hits.html', {'tags':tag_list, 'prefix':prefix},
+        form = PublishingSuggestForm(initial={"books": prefix + ", "})
+        return render_to_response('catalogue/search_no_hits.html',
+            {'tags':tag_list, 'prefix':prefix, "pubsuggest_form": form},
             context_instance=RequestContext(request))
 
 
@@ -283,225 +453,30 @@ def tags_starting_with(request):
     # Prefix must have at least 2 characters
     if len(prefix) < 2:
         return HttpResponse('')
-    
-    return HttpResponse('\n'.join(tag.name for tag in _tags_starting_with(prefix, request.user)))
-
-
-# ====================
-# = Shelf management =
-# ====================
-@login_required
-@cache.never_cache
-def user_shelves(request):
-    shelves = models.Tag.objects.filter(category='set', user=request.user)
-    new_set_form = forms.NewSetForm()
-    return render_to_response('catalogue/user_shelves.html', locals(),
-            context_instance=RequestContext(request))
-
-@cache.never_cache
-def book_sets(request, slug):
-    book = get_object_or_404(models.Book, slug=slug)
-    user_sets = models.Tag.objects.filter(category='set', user=request.user)
-    book_sets = book.tags.filter(category='set', user=request.user)
-    
-    if not request.user.is_authenticated():
-        return HttpResponse(_('<p>To maintain your shelves you need to be logged in.</p>'))
-    
-    if request.method == 'POST':
-        form = forms.ObjectSetsForm(book, request.user, request.POST)
-        if form.is_valid():
-            old_shelves = list(book.tags.filter(category='set'))
-            new_shelves = [models.Tag.objects.get(pk=id) for id in form.cleaned_data['set_ids']]
-            
-            for shelf in [shelf for shelf in old_shelves if shelf not in new_shelves]:
-                shelf.book_count -= 1
-                shelf.save()
-                
-            for shelf in [shelf for shelf in new_shelves if shelf not in old_shelves]:
-                shelf.book_count += 1
-                shelf.save()
-            
-            book.tags = new_shelves + list(book.tags.filter(~Q(category='set') | ~Q(user=request.user)))
-            if request.is_ajax():
-                return HttpResponse(_('<p>Shelves were sucessfully saved.</p>'))
-            else:
-                return HttpResponseRedirect('/')
-    else:
-        form = forms.ObjectSetsForm(book, request.user)
-        new_set_form = forms.NewSetForm()
-    
-    return render_to_response('catalogue/book_sets.html', locals(),
-        context_instance=RequestContext(request))
-
-
-@login_required
-@require_POST
-@cache.never_cache
-def remove_from_shelf(request, shelf, book):
-    book = get_object_or_404(models.Book, slug=book)
-    shelf = get_object_or_404(models.Tag, slug=shelf, category='set', user=request.user)
-    
-    if shelf in book.tags:
-        models.Tag.objects.remove_tag(book, shelf)
-
-        shelf.book_count -= 1
-        shelf.save()
-
-        return HttpResponse(_('Book was successfully removed from the shelf'))
-    else:
-        return HttpResponse(_('This book is not on the shelf'))
-
-
-def collect_books(books):
-    """
-    Returns all real books in collection.
-    """
-    result = []
-    for book in books:
-        if len(book.children.all()) == 0:
-            result.append(book)
-        else:
-            result += collect_books(book.children.all())
-    return result
-
-
-@cache.never_cache
-def download_shelf(request, slug):
-    """"
-    Create a ZIP archive on disk and transmit it in chunks of 8KB,
-    without loading the whole file into memory. A similar approach can
-    be used for large dynamic PDF files.                                        
-    """
-    shelf = get_object_or_404(models.Tag, slug=slug, category='set')
-    
-    formats = []
-    form = forms.DownloadFormatsForm(request.GET)
-    if form.is_valid():
-        formats = form.cleaned_data['formats']
-    if len(formats) == 0:
-        formats = ['pdf', 'odt', 'txt', 'mp3', 'ogg']
-    
-    # Create a ZIP archive
-    temp = tempfile.TemporaryFile()
-    archive = zipfile.ZipFile(temp, 'w')
-    
-    for book in collect_books(models.Book.tagged.with_all(shelf)):
-        if 'pdf' in formats and book.pdf_file:
-            filename = book.pdf_file.path
-            archive.write(filename, str('%s.pdf' % book.slug))
-        if 'odt' in formats and book.odt_file:
-            filename = book.odt_file.path
-            archive.write(filename, str('%s.odt' % book.slug))
-        if 'txt' in formats and book.txt_file:
-            filename = book.txt_file.path
-            archive.write(filename, str('%s.txt' % book.slug))
-        if 'mp3' in formats and book.mp3_file:
-            filename = book.mp3_file.path
-            archive.write(filename, str('%s.mp3' % book.slug))
-        if 'ogg' in formats and book.ogg_file:
-            filename = book.ogg_file.path
-            archive.write(filename, str('%s.ogg' % book.slug))
-    archive.close()
-    
-    response = HttpResponse(content_type='application/zip', mimetype='application/x-zip-compressed')
-    response['Content-Disposition'] = 'attachment; filename=%s.zip' % shelf.sort_key
-    response['Content-Length'] = temp.tell()
-    
-    temp.seek(0)
-    response.write(temp.read())
-    return response
-
-
-@cache.never_cache
-def shelf_book_formats(request, shelf):
-    """"
-    Returns a list of formats of books in shelf.
-    """
-    shelf = get_object_or_404(models.Tag, slug=shelf, category='set')
-
-    formats = {'pdf': False, 'odt': False, 'txt': False, 'mp3': False, 'ogg': False}
-    
-    for book in collect_books(models.Book.tagged.with_all(shelf)):
-        if book.pdf_file:
-            formats['pdf'] = True
-        if book.odt_file:
-            formats['odt'] = True
-        if book.txt_file:
-            formats['txt'] = True
-        if book.mp3_file:
-            formats['mp3'] = True
-        if book.ogg_file:
-            formats['ogg'] = True
-
-    return HttpResponse(LazyEncoder().encode(formats))
-
-
-@login_required
-@require_POST
-@cache.never_cache
-def new_set(request):
-    new_set_form = forms.NewSetForm(request.POST)
-    if new_set_form.is_valid():
-        new_set = new_set_form.save(request.user)
-
-        if request.is_ajax():
-            return HttpResponse(_('<p>Shelf <strong>%s</strong> was successfully created</p>') % new_set)
-        else:
-            return HttpResponseRedirect('/')
-
-    return HttpResponseRedirect('/')
-
-
-@login_required
-@require_POST
-@cache.never_cache
-def delete_shelf(request, slug):
-    user_set = get_object_or_404(models.Tag, slug=slug, category='set', user=request.user)
-    user_set.delete()
-
-    if request.is_ajax():
-        return HttpResponse(_('<p>Shelf <strong>%s</strong> was successfully removed</p>') % user_set.name)
-    else:
-        return HttpResponseRedirect('/')
-
-
-# ==================
-# = Authentication =
-# ==================
-@require_POST
-@cache.never_cache
-def login(request):
-    form = AuthenticationForm(data=request.POST, prefix='login')
-    if form.is_valid():
-        auth.login(request, form.get_user())
-        response_data = {'success': True, 'errors': {}}
-    else:
-        response_data = {'success': False, 'errors': form.errors}
-    return HttpResponse(LazyEncoder(ensure_ascii=False).encode(response_data))
-
-
-@require_POST
-@cache.never_cache
-def register(request):
-    registration_form = UserCreationForm(request.POST, prefix='registration')
-    if registration_form.is_valid():
-        user = registration_form.save()
-        user = auth.authenticate(
-            username=registration_form.cleaned_data['username'], 
-            password=registration_form.cleaned_data['password1']
-        )
-        auth.login(request, user)
-        response_data = {'success': True, 'errors': {}}
+    tags_list = []
+    result = ""
+    for tag in _tags_starting_with(prefix, request.user):
+        if not tag.name in tags_list:
+            result += "\n" + tag.name
+            tags_list.append(tag.name)
+    return HttpResponse(result)
+
+def json_tags_starting_with(request, callback=None):
+    # Callback for JSONP
+    prefix = request.GET.get('q', '')
+    callback = request.GET.get('callback', '')
+    # Prefix must have at least 2 characters
+    if len(prefix) < 2:
+        return HttpResponse('')
+    tags_list = []
+    for tag in _tags_starting_with(prefix, request.user):
+        if not tag.name in tags_list:
+            tags_list.append(tag.name)
+    if request.GET.get('mozhint', ''):
+        result = [prefix, tags_list]
     else:
-        response_data = {'success': False, 'errors': registration_form.errors}
-    return HttpResponse(LazyEncoder(ensure_ascii=False).encode(response_data))
-
-
-@cache.never_cache
-def logout_then_redirect(request):
-    auth.logout(request)
-    return HttpResponseRedirect(urlquote_plus(request.GET.get('next', '/'), safe='/?='))
-
+        result = {"matches": tags_list}
+    return JSONResponse(result, callback)
 
 
 # =========
@@ -516,20 +491,62 @@ def import_book(request):
         try:
             book_import_form.save()
         except:
+            import sys
+            import pprint
+            import traceback
             info = sys.exc_info()
             exception = pprint.pformat(info[1])
             tb = '\n'.join(traceback.format_tb(info[2]))
-            _('Today is %(month)s, %(day)s.') % {'month': m, 'day': d}
             return HttpResponse(_("An error occurred: %(exception)s\n\n%(tb)s") % {'exception':exception, 'tb':tb}, mimetype='text/plain')
         return HttpResponse(_("Book imported successfully"))
     else:
         return HttpResponse(_("Error importing file: %r") % book_import_form.errors)
 
 
+# info views for API
 
-def clock(request):
-    """ Provides server time for jquery.countdown,
-    in a format suitable for Date.parse()
-    """
-    from datetime import datetime
-    return HttpResponse(datetime.now().strftime('%Y/%m/%d %H:%M:%S'))
\ No newline at end of file
+def book_info(request, id, lang='pl'):
+    book = get_object_or_404(models.Book, id=id)
+    # set language by hand
+    translation.activate(lang)
+    return render_to_response('catalogue/book_info.html', locals(),
+        context_instance=RequestContext(request))
+
+
+def tag_info(request, id):
+    tag = get_object_or_404(models.Tag, id=id)
+    return HttpResponse(tag.description)
+
+
+def download_zip(request, format, slug=None):
+    url = None
+    if format in models.Book.ebook_formats:
+        url = models.Book.zip_format(format)
+    elif format in ('mp3', 'ogg') and slug is not None:
+        book = get_object_or_404(models.Book, slug=slug)
+        url = book.zip_audiobooks(format)
+    else:
+        raise Http404('No format specified for zip package')
+    return HttpResponseRedirect(urlquote_plus(settings.MEDIA_URL + url, safe='/?='))
+
+
+class CustomPDFFormView(AjaxableFormView):
+    form_class = forms.CustomPDFForm
+    title = ugettext_lazy('Download custom PDF')
+    submit = ugettext_lazy('Download')
+    honeypot = True
+
+    def __call__(self, *args, **kwargs):
+        if settings.NO_CUSTOM_PDF:
+            raise Http404('Custom PDF is disabled')
+        return super(CustomPDFFormView, self).__call__(*args, **kwargs)
+
+    def form_args(self, request, obj):
+        """Override to parse view args and give additional args to the form."""
+        return (obj,), {}
+
+    def get_object(self, request, slug, *args, **kwargs):
+        return get_object_or_404(models.Book, slug=slug)
+
+    def context_description(self, request, obj):
+        return obj.pretty_title()