minor fix
[wolnelektury.git] / apps / api / handlers.py
index 799b608..706e0cd 100644 (file)
 # -*- 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.
-#
-from django.shortcuts import get_object_or_404
-from django.contrib.auth.decorators import login_required, user_passes_test
+
+from datetime import datetime, timedelta
 from piston.handler import BaseHandler
-from piston.utils import rc, validate
-from catalogue.models import Book
-from catalogue.forms import BookImportForm
+from django.conf import settings
+
+from api.helpers import timestamp
+from api.models import Deleted
+from catalogue.models import Book, Tag
+
+
+class CatalogueHandler(BaseHandler):
 
+    @staticmethod
+    def fields(request, name):
+        fields_str = request.GET.get(name) if request is not None else None
+        return fields_str.split(',') if fields_str is not None else None
 
-staff_required = user_passes_test(lambda user: user.is_staff)
+    @staticmethod
+    def until(t=None):
+        """ Returns time suitable for use as upper time boundary for check.
+        
+            Defaults to 'five minutes ago' to avoid issues with time between
+            change stamp set and model save.
+            Cuts the microsecond part to avoid issues with DBs where time has
+            more precision.
 
+        """
+        # set to five minutes ago, to avoid concurrency issues
+        if t is None:
+            t = datetime.now() - timedelta(seconds=settings.API_WAIT)
+        # set to whole second in case DB supports something smaller
+        return t.replace(microsecond=0)
 
-class BookHandler(BaseHandler):
-    model = Book
-    fields = ('slug', 'title')
-    
-    @staff_required
-    def read(self, request, slug=None):
-        if slug:
-            return get_object_or_404(Book, slug=slug)
+    @staticmethod
+    def book_dict(book, fields=None):
+        all_fields = ('url', 'title', 'description',
+                      'gazeta_link', 'wiki_link',
+                      'xml', 'epub', 'txt', 'pdf', 'html',
+                      'mp3', 'ogg', 'daisy',
+                      'parent', 'parent_number',
+                      'tags',
+                      'license', 'license_description', 'source_name',
+                      'technical_editors', 'editors',
+                      'author', 'sort_key',
+                     )
+        if fields:
+            fields = (f for f in fields if f in all_fields)
         else:
-            return Book.objects.all()
-    
-    @staff_required
-    def create(self, request):
-        form = BookImportForm(request.POST, request.FILES)
-        if form.is_valid():
-            form.save()
-            return rc.CREATED
+            fields = all_fields
+
+        extra_info = book.get_extra_info_value()
+
+        obj = {}
+        for field in fields:
+
+            if field in ('xml', 'epub', 'txt', 'pdf', 'html'):
+                f = getattr(book, field+'_file')
+                if f:
+                    obj[field] = {
+                        'url': f.url,
+                        'size': f.size,
+                    }
+
+            elif field in ('mp3', 'ogg', 'daisy'):
+                media = []
+                for m in book.media.filter(type=field):
+                    media.append({
+                        'url': m.file.url,
+                        'size': m.file.size,
+                    })
+                if media:
+                    obj[field] = media
+
+            elif field == 'url':
+                obj[field] = book.get_absolute_url()
+
+            elif field == 'tags':
+                obj[field] = [t.id for t in book.tags.exclude(category__in=('book', 'set'))]
+
+            elif field == 'author':
+                obj[field] = ", ".join(t.name for t in book.tags.filter(category='author'))
+
+            elif field == 'parent':
+                obj[field] = book.parent_id
+
+            elif field in ('license', 'license_description', 'source_name',
+                      'technical_editors', 'editors'):
+                f = extra_info.get(field)
+                if f:
+                    obj[field] = f
+
+            else:
+                f = getattr(book, field)
+                if f:
+                    obj[field] = f
+
+        obj['id'] = book.id
+        return obj
+
+    @classmethod
+    def book_changes(cls, request=None, since=0, until=None, fields=None):
+        since = datetime.fromtimestamp(int(since))
+        until = cls.until(until)
+
+        changes = {
+            'time_checked': timestamp(until)
+        }
+
+        if not fields:
+            fields = cls.fields(request, 'book_fields')
+
+        added = []
+        updated = []
+        deleted = []
+
+        last_change = since
+        for book in Book.objects.filter(changed_at__gte=since,
+                    changed_at__lt=until):
+            book_d = cls.book_dict(book, fields)
+            updated.append(book_d)
+        if updated:
+            changes['updated'] = updated
+
+        for book in Deleted.objects.filter(content_type=Book, 
+                    deleted_at__gte=since,
+                    deleted_at__lt=until,
+                    created_at__lt=since):
+            deleted.append(book.id)
+        if deleted:
+            changes['deleted'] = deleted
+
+        return changes
+
+    @staticmethod
+    def tag_dict(tag, fields=None):
+        all_fields = ('name', 'category', 'sort_key', 'description',
+                      'gazeta_link', 'wiki_link',
+                      'url', 'books',
+                     )
+
+        if fields:
+            fields = (f for f in fields if f in all_fields)
         else:
-            return rc.BAD_REQUEST
+            fields = all_fields
+
+        obj = {}
+        for field in fields:
+
+            if field == 'url':
+                obj[field] = tag.get_absolute_url()
+
+            elif field == 'books':
+                obj[field] = [b.id for b in Book.tagged_top_level([tag])]
+
+            elif field == 'sort_key':
+                obj[field] = tag.sort_key
+
+            else:
+                f = getattr(tag, field)
+                if f:
+                    obj[field] = f
+
+        obj['id'] = tag.id
+        return obj
+
+    @classmethod
+    def tag_changes(cls, request=None, since=0, until=None, fields=None, categories=None):
+        since = datetime.fromtimestamp(int(since))
+        until = cls.until(until)
+
+        changes = {
+            'time_checked': timestamp(until)
+        }
+
+        if not fields:
+            fields = cls.fields(request, 'tag_fields')
+        if not categories:
+            categories = cls.fields(request, 'tag_categories')
+
+        all_categories = ('author', 'epoch', 'kind', 'genre')
+        if categories:
+            categories = (c for c in categories if c in all_categories)
+        else:
+            categories = all_categories
+
+        updated = []
+        deleted = []
+
+        for tag in Tag.objects.filter(category__in=categories, 
+                    changed_at__gte=since,
+                    changed_at__lt=until):
+            # only serve non-empty tags
+            if tag.get_count():
+                tag_d = cls.tag_dict(tag, fields)
+                updated.append(tag_d)
+            elif tag.created_at < since:
+                deleted.append(tag.id)
+        if updated:
+            changes['updated'] = updated
+
+        for tag in Deleted.objects.filter(category__in=categories,
+                content_type=Tag, 
+                    deleted_at__gte=since,
+                    deleted_at__lt=until,
+                    created_at__lt=since):
+            deleted.append(tag.id)
+        if deleted:
+            changes['deleted'] = deleted
+
+        return changes
+
+    @classmethod
+    def changes(cls, request=None, since=0, until=None, book_fields=None,
+                tag_fields=None, tag_categories=None):
+        until = cls.until(until)
+
+        changes = {
+            'time_checked': timestamp(until)
+        }
+
+        changes_by_type = {
+            'books': cls.book_changes(request, since, until, book_fields),
+            'tags': cls.tag_changes(request, since, until, tag_fields, tag_categories),
+        }
+
+        for model in changes_by_type:
+            for field in changes_by_type[model]:
+                if field == 'time_checked':
+                    continue
+                changes.setdefault(field, {})[model] = changes_by_type[model][field]
+        return changes
+
+
+class BookChangesHandler(CatalogueHandler):
+    allowed_methods = ('GET',)
+
+    def read(self, request, since):
+        return self.book_changes(request, since)
+
+
+class TagChangesHandler(CatalogueHandler):
+    allowed_methods = ('GET',)
+
+    def read(self, request, since):
+        return self.tag_changes(request, since)
+
+
+class ChangesHandler(CatalogueHandler):
+    allowed_methods = ('GET',)
 
+    def read(self, request, since):
+        return self.changes(request, since)