Recognize the 3 variants of the Public collection URI when parsing audience

src/Web/ActivityPub.hs

@@ -43,6 +43,7 @@ module Web.ActivityPub
     , Activity (..)
 
       -- * Utilities
+    , publicURI
     , hActivityPubActor
     , provideAP
     , APGetError (..)
@@ -110,6 +111,12 @@ as2context = "https://www.w3.org/ns/activitystreams"
 secContext :: Text
 secContext = "https://w3id.org/security/v1"
 
+publicURI :: FedURI
+publicURI = FedURI "www.w3.org" "/ns/activitystreams" "#Public"
+
+publicT :: Text
+publicT = renderFedURI publicURI
+
 actorContext :: [Text]
 actorContext = [as2context, secContext]
 
@@ -407,6 +414,20 @@ data Audience = Audience
     , audienceGeneral :: Vector FedURI
     }
 
+newtype AdaptAudience = AdaptAudience
+    { unAdapt :: FedURI
+    }
+
+instance FromJSON AdaptAudience where
+    parseJSON = parseJSON . adapt
+        where
+        adapt v =
+            case v of
+                String t
+                    | t == "Public"    -> String publicT
+                    | t == "as:Public" -> String publicT
+                _ -> v
+
 parseAudience :: Object -> Parser Audience
 parseAudience o =
     Audience
@@ -415,6 +436,10 @@ parseAudience o =
         <*> o .:? "cc"       .!= V.empty
         <*> o .:? "bcc"      .!= V.empty
         <*> o .:? "audience" .!= V.empty
+    where
+    obj .:& key = do
+        vec <- obj .:? key .!= V.empty
+        return $ unAdapt <$> vec
 
 encodeAudience :: Audience -> Series
 encodeAudience (Audience to bto cc bcc aud)