X-Git-Url: https://git.mdrn.pl/wolnelektury.git/blobdiff_plain/6aa28c35d2d68f512ba2ae2fdde2c5e5b5d8e808..3b432b134c57aad46da1eadebc31f01d35368719:/apps/catalogue/views.py

diff --git a/apps/catalogue/views.py b/apps/catalogue/views.py
index bf52dc43c..79faca7a4 100644
--- a/apps/catalogue/views.py
+++ b/apps/catalogue/views.py
@@ -1,10 +1,23 @@
 # -*- coding: utf-8 -*-
+# 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 operator import itemgetter
+
+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.core.urlresolvers import reverse
 from django.db.models import Q
-from django.contrib.auth.decorators import login_required
+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
@@ -12,6 +25,10 @@ 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.views.generic.list_detail import object_list
 
 from catalogue import models
 from catalogue import forms
@@ -19,248 +36,657 @@ from catalogue.utils import split_tags
 from newtagging import views as newtagging_views
 
 
+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 search(request):
-    query = request.GET.get('q', '')
-    tags = request.GET.get('tags', '')
-    if tags == '':
-        tags = []
-    
-    try:
-        tag_list = models.Tag.get_tag_list(tags)
-        tag = models.Tag.objects.get(name=query)
-    except models.Tag.DoesNotExist:
-        try:
-            book = models.Book.objects.get(title=query)
-            return HttpResponseRedirect(book.get_absolute_url())
-        except models.Book.DoesNotExist:
-            return HttpResponseRedirect(reverse('catalogue.views.main_page'))
-    else:
-        tag_list.append(tag)
-        return HttpResponseRedirect(reverse('catalogue.views.tagged_object_list', 
-            kwargs={'tags': '/'.join(tag.slug for tag in tag_list)}
-        ))
-
-
-def tags_starting_with(request):
-    try:
-        prefix = request.GET['q']
-        if len(prefix) < 2:
-            raise KeyError
-            
-        books = models.Book.objects.filter(title__icontains=prefix)
-        tags = models.Tag.objects.filter(name__icontains=prefix)
-        if request.user.is_authenticated():
-            tags = tags.filter(~Q(category='set') | Q(user=request.user))
-        else:
-            tags = tags.filter(~Q(category='set'))
-        
-        completions = [book.title for book in books] + [tag.name for tag in tags]
-
-        return HttpResponse('\n'.join(completions))    
-    
-    except KeyError:
-        return HttpResponse('')
+# shortcut for JSON reponses
+class JSONResponse(HttpResponse):
+    def __init__(self, data={}, callback=None, **kwargs):
+        # get rid of mimetype
+        kwargs.pop('mimetype', None)
+        data = simplejson.dumps(data)
+        if callback:
+            data = callback + "(" + data + ");" 
+        super(JSONResponse, self).__init__(data, mimetype="application/json", **kwargs)
 
 
-def main_page(request):    
+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]})
+
+    tags = models.Tag.objects.exclude(category__in=('set', 'book'))
+    for tag in tags:
+        tag.count = tag.get_count()
     categories = split_tags(tags)
-    
+    fragment_tags = categories.get('theme', [])
+
     form = forms.SearchForm()
     return render_to_response('catalogue/main_page.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)
-    
+
+    books_by_parent = {}
+    for book in models.Book.objects.all().order_by('parent_number'):
+        books_by_parent.setdefault(book.parent, []).append(book)
+
+    orphans = []
+    books_by_author = SortedDict()
+    books_nav = SortedDict()
+    for tag in models.Tag.objects.filter(category='author'):
+        books_by_author[tag] = []
+        if books_nav.has_key(tag.sort_key[0]):
+            books_nav[tag.sort_key[0]].append(tag)
+        else:
+            books_nav[tag.sort_key[0]] = [tag]
+
+    for book in books_by_parent[None]:
+        authors = list(book.tags.filter(category='author'))
+        if authors:
+            for author in authors:
+                books_by_author[author].append(book)
+        else:
+            orphans.append(book)
+
     return render_to_response('catalogue/book_list.html', locals(),
         context_instance=RequestContext(request))
 
 
+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))
+
+
 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
-    
-    model = models.Book
-    shelf_is_set = (len(tags) == 1 and tags[0].category == 'set')
-    theme_is_set = any(tag.category == 'theme' for tag in tags)
-    if theme_is_set:
-        model = models.Fragment
+    except models.Tag.MultipleObjectsReturned, e:
+        return differentiate_tags(request, e.tags, e.ambiguous_slugs)
+
+    try:
+        if len(tags) > settings.MAX_TAG_LIST:
+            raise Http404
+    except AttributeError:
+        pass
 
-    extra_where = 'NOT catalogue_tag.category = "set"'
-    related_tags = models.Tag.objects.related_for_model(tags, model, counts=True, extra={'where': [extra_where]})
-    categories = split_tags(related_tags)
+    if len([tag for tag in tags if tag.category == 'book']):
+        raise Http404
 
-    if not theme_is_set:
-        model=models.Book.objects.filter(parent=None)
-    
-    return newtagging_views.tagged_object_list(
+    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 = pd_counter = None
+    categories = {}
+
+    if theme_is_set:
+        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])
+            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]
+        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:
+        # get relevant books and their tags
+        objects = models.Book.tagged.with_all(tags)
+        if not shelf_is_set:
+            # eliminate descendants
+            l_tags = models.Tag.objects.filter(category='book', slug__in=[book.book_tag_slug() for book in objects])
+            descendants_keys = [book.pk for book in models.Book.tagged.with_any(l_tags)]
+            if descendants_keys:
+                objects = objects.exclude(pk__in=descendants_keys)
+
+        # get related tags from `tag_counter` and `theme_counter`
+        related_counts = {}
+        tags_pks = [tag.pk for tag in tags]
+        for book in objects:
+            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'
+        pd_counter = only_author and tags[0].goes_to_pd()
+        objects = models.Book.objects.none()
+
+    return object_list(
         request,
-        tag_model=models.Tag,
-        queryset_or_model=model,
-        tags=tags,
+        objects,
         template_name='catalogue/tagged_object_list.html',
-        extra_context = {'categories': categories, 'shelf_is_set': shelf_is_set },
+        extra_context={
+            'categories': categories,
+            'only_shelf': only_shelf,
+            'only_author': only_author,
+            'pd_counter': pd_counter,
+            'only_my_shelf': only_my_shelf,
+            'formats_form': forms.DownloadFormatsForm(),
+
+            'tags': tags,
+        }
     )
 
 
+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, category='book')
+    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))
+
+
 def book_detail(request, slug):
-    book = get_object_or_404(models.Book, slug=slug)
+    try:
+        book = models.Book.objects.get(slug=slug)
+    except models.Book.DoesNotExist:
+        return book_stub_detail(request, slug)
+
+    book_tag = book.book_tag()
     tags = list(book.tags.filter(~Q(category='set')))
     categories = split_tags(tags)
     book_children = book.children.all().order_by('parent_number')
     
+    _book = book
+    parents = []
+    while _book.parent:
+        parents.append(_book.parent)
+        _book = _book.parent
+    parents = reversed(parents)
+
+    theme_counter = book.theme_counter
+    book_themes = models.Tag.objects.filter(pk__in=theme_counter.keys())
+    for tag in book_themes:
+        tag.count = theme_counter[tag.pk]
+
+    extra_info = book.get_extra_info_value()
+
     form = forms.SearchForm()
     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(),
+        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'):
+            book_themes.setdefault(theme, []).append(fragment)
+
+    book_themes = book_themes.items()
+    book_themes.sort(key=lambda s: s[0].sort_key)
     return render_to_response('catalogue/book_text.html', locals(),
         context_instance=RequestContext(request))
 
 
-def logout_then_redirect(request):
-    auth.logout(request)
-    return HttpResponseRedirect(request.GET.get('next', '/'))
+# ==========
+# = Search =
+# ==========
 
+def _no_diacritics_regexp(query):
+    """ returns a regexp for searching for a query without diacritics
 
-@require_POST
-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']
+    should be locale-aware """
+    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 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 = {}
+
+    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 _sqlite_word_starts_with(name, prefix):
+    """ version of _word_starts_with for SQLite
+
+    SQLite in Django uses Python re module
+    """
+    kwargs = {}
+    prefix = _no_diacritics_regexp(unicode_re_escape(prefix))
+    kwargs['%s__iregex' % name] = ur"(^|(?<=[^\wąćęłńóśźżĄĆĘŁŃÓŚŹŻ]))%s" % prefix
+    return Q(**kwargs)
+
+
+if settings.DATABASE_ENGINE == 'sqlite3':
+    _word_starts_with = _sqlite_word_starts_with
+
+
+def _tags_starting_with(prefix, user=None):
+    prefix = prefix.lower()
+    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 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)
+
+
+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.url_chunk for tag in tag_list + [match])}
         )
-        auth.login(request, user)
-        response_data = {'success': True, 'errors': {}}
+
+def _get_result_type(match):
+    if isinstance(match, models.Book) or isinstance(match, models.BookStub):
+        type = 'book'
     else:
-        response_data = {'success': False, 'errors': registration_form.errors}
-    return HttpResponse(LazyEncoder(ensure_ascii=False).encode(response_data))
+        type = match.category
+    return type
 
 
-@require_POST
-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': {}}
+
+def find_best_matches(query, user=None):
+    """ Finds a Book, Tag or Bookstub 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))
+    exact_matches = tuple(res for res in result if res.name.lower() == query)
+    if exact_matches:
+        return exact_matches
     else:
-        response_data = {'success': False, 'errors': form.errors}
-    return HttpResponse(LazyEncoder(ensure_ascii=False).encode(response_data))
+        return 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 = []
+
+    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))
+
+    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))
+    else:
+        return render_to_response('catalogue/search_no_hits.html', {'tags':tag_list, 'prefix':prefix},
+            context_instance=RequestContext(request))
 
 
+def tags_starting_with(request):
+    prefix = request.GET.get('q', '')
+    # Prefix must have at least 2 characters
+    if len(prefix) < 2:
+        return HttpResponse('')
+    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 = []
+    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)
+    dict_result = {"matches": tags_list}
+    return JSONResponse(dict_result, callback)
+
+# ====================
+# = 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>Aby zarządzać swoimi półkami, musisz się zalogować.</p>')
-    
+        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():
-            book.tags = ([models.Tag.objects.get(pk=id) for id in form.cleaned_data['set_ids']] +
-                list(book.tags.filter(~Q(category='set') | ~Q(user=request.user))))
+            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 = None
+                shelf.save()
+
+            for shelf in [shelf for shelf in new_shelves if shelf not in old_shelves]:
+                shelf.book_count = None
+                shelf.save()
+
+            book.tags = new_shelves + list(book.tags.filter(~Q(category='set') | ~Q(user=request.user)))
             if request.is_ajax():
-                return HttpResponse('<p>Półki zostały zapisane.</p>')
+                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))
 
 
-def fragment_sets(request, id):
-    fragment = get_object_or_404(models.Fragment, pk=id)
-    user_sets = models.Tag.objects.filter(category='set', user=request.user)
-    fragment_sets = fragment.tags.filter(category='set', user=request.user)
+@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 not request.user.is_authenticated():
-        return HttpResponse('<p>Aby zarządzać swoimi półkami, musisz się zalogować.</p>')
+    if shelf in book.tags:
+        models.Tag.objects.remove_tag(book, shelf)
 
-    if request.method == 'POST':
-        form = forms.ObjectSetsForm(fragment, request.user, request.POST)
-        if form.is_valid():
-            fragment.tags = ([models.Tag.objects.get(pk=id) for id in form.cleaned_data['set_ids']] +
-                list(fragment.tags.filter(~Q(category='set') | ~Q(user=request.user))))
-            if request.is_ajax():
-                return HttpResponse('<p>Półki zostały zapisane.</p>')
-            else:
-                return HttpResponseRedirect('/')
+        shelf.book_count = None
+        shelf.save()
+
+        return HttpResponse(_('Book was successfully removed from the shelf'))
     else:
-        form = forms.ObjectSetsForm(fragment, request.user)
-        new_set_form = forms.NewSetForm()
+        return HttpResponse(_('This book is not on the shelf'))
 
-    return render_to_response('catalogue/fragment_sets.html', locals(),
-        context_instance=RequestContext(request))
+
+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', 'epub', 'odt', 'txt', 'mp3', 'ogg']
+
+    # Create a ZIP archive
+    temp = tempfile.TemporaryFile()
+    archive = zipfile.ZipFile(temp, 'w')
+
+    already = set()
+    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 book.root_ancestor not in already and 'epub' in formats and book.root_ancestor.epub_file:
+            filename = book.root_ancestor.epub_file.path
+            archive.write(filename, str('%s.epub' % book.root_ancestor.slug))
+            already.add(book.root_ancestor)
+        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, 'epub': 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.root_ancestor.epub_file:
+            formats['epub'] = 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(u'<p>Półka <strong>%s</strong> została utworzona</p>' % new_set)
+            return HttpResponse(_('<p>Shelf <strong>%s</strong> was successfully created</p>') % new_set)
         else:
             return HttpResponseRedirect('/')
-    
-    return render_to_response('catalogue/book_sets.html', locals(),
-            context_instance=RequestContext(request))
+
+    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(u'<p>Półka <strong>%s</strong> została usunięta</p>' % user_set.name)
+        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': {}}
+    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='/?='))
+
+
+
+# =========
+# = Admin =
+# =========
 @login_required
-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))
+@staff_required
+def import_book(request):
+    """docstring for import_book"""
+    book_import_form = forms.BookImportForm(request.POST, request.FILES)
+    if book_import_form.is_valid():
+        try:
+            book_import_form.save()
+        except:
+            info = sys.exc_info()
+            exception = pprint.pformat(info[1])
+            tb = '\n'.join(traceback.format_tb(info[2]))
+            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)
+
+
 
+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'))