Use dataclasses to define activitypub (de)serialization (#177)

* Use dataclasses to define activitypub (de)serialization

fedireads/activitypub/__init__.py

@@ -1,16 +1,19 @@
 ''' bring activitypub functions into the namespace '''
-from .actor import get_actor
-from .book import get_book, get_author, get_shelf
-from .create import get_create, get_update
-from .follow import get_following, get_followers
-from .follow import get_follow_request, get_unfollow, get_accept, get_reject
-from .outbox import get_outbox, get_outbox_page
-from .shelve import get_add, get_remove
-from .status import get_review, get_review_article
-from .status import get_rating, get_rating_note
-from .status import get_comment, get_comment_article
-from .status import get_quotation, get_quotation_article
-from .status import get_status, get_replies, get_replies_page
-from .status import get_favorite, get_unfavorite
-from .status import get_boost
-from .status import get_add_tag, get_remove_tag
+import inspect
+import sys
+
+from .base_activity import ActivityEncoder, Image, PublicKey, Signature
+from .note import Note, Article, Comment, Review, Quotation
+from .interaction import Boost, Like
+from .ordered_collection import OrderedCollection, OrderedCollectionPage
+from .person import Person
+from .book import Edition, Work, Author
+from .verbs import Create, Undo, Update
+from .verbs import Follow, Accept, Reject
+from .verbs import Add, Remove
+
+# this creates a list of all the Activity types that we can serialize,
+# so when an Activity comes in from outside, we can check if it's known
+cls_members = inspect.getmembers(sys.modules[__name__], inspect.isclass)
+activity_objects = {c[0]: c[1] for c in cls_members \
+    if hasattr(c[1], 'to_model')}