explicit first and last, and no field selectors

fedi.cabal

@@ -53,6 +53,7 @@ library
     DeriveAnyClass
     DerivingStrategies
     DuplicateRecordFields
+    NoFieldSelectors
 
 executable fedi
   import: warnings

src/Fedi/Activity.hs

@@ -1,6 +1,5 @@
 module Fedi.Activity where
 
-import Data.Maybe (listToMaybe)
 import Data.Aeson qualified as A
 import Data.Text qualified as T
 import Fedi.Types
@@ -14,6 +13,10 @@ data Activity
     , object :: Object
     }
 
+activityUrl :: Activity -> ActivityUrl
+activityUrl = \case
+  create@Create{} -> create.id
+
 type ActivityUrl = Url
 
 data Object
@@ -52,6 +55,8 @@ data Collection order a
   = Collection
     { summary :: String
     , items :: [a]
+    , first :: Maybe Url
+    , last :: Maybe Url
     }
 
 instance A.ToJSON Note where
@@ -95,8 +100,8 @@ instance A.ToJSON a => A.ToJSON (Collection Ordered a) where
       , "summary" A..= collection.summary
       , "totalItems" A..= length collection.items
       , "orderedItems" A..= collection.items
-      , "first" A..= listToMaybe (take 1 collection.items)
-      , "last" A..= listToMaybe (take 1 $ reverse collection.items)
+      , "first" A..= collection.first
+      , "last" A..= collection.last
       ]
 
 instance A.ToJSON a => A.ToJSON (Collection Unordered a) where
@@ -109,8 +114,8 @@ instance A.ToJSON a => A.ToJSON (Collection Unordered a) where
       , "summary" A..= collection.summary
       , "totalItems" A..= length collection.items
       , "items" A..= collection.items
-      , "first" A..= listToMaybe (take 1 collection.items)
-      , "last" A..= listToMaybe (take 1 $ reverse collection.items)
+      , "first" A..= collection.first
+      , "last" A..= collection.last
       ]
 
 instance A.ToJSON a => A.ToJSON (OrderedCollectionPage a) where

src/Fedi/Routes.hs

@@ -1,5 +1,6 @@
 module Fedi.Routes where
 
+import Data.Maybe (listToMaybe)
 import Web.Twain qualified as Twain
 import Web.Twain.Types qualified as Twain
 import Data.String (fromString)
@@ -91,6 +92,8 @@ handleOutbox details items = do
               Collection
                 { summary = details.username <> "'s notes"
                 , items = items
+                , first = Just $ outboxUrl <> "?page=true"
+                , last = Nothing
                 }
           in A.encode content
   Twain.send $ jsonLD response