add edit page

frontend/app/Api.hs

@@ -3,6 +3,8 @@
 module Api
   ( fetchSchema,
     fetchPosts,
+    fetchPost,
+    updatePost,
   )
 where
 
@@ -18,8 +20,10 @@ import Miso.String qualified as J
 #endif
 import Data.Aeson qualified as A
 import Data.ByteString.Lazy.Char8 qualified as LB
+import Data.ByteString.Lazy.UTF8 qualified as LB
 import Data.Function
 import Miso
+import Safe
 import Schema
 
 fetchSchema :: JSM (Either String Schema)
@@ -35,6 +39,24 @@ fetchPosts =
           & setRequestBodyLBS "SELECT posts FROM posts"
       )
 
+fetchPost :: String -> JSM (Either String (Maybe A.Value))
+fetchPost fileName =
+  fmap headMay . A.eitherDecode
+    <$> fetch
+      ( fromString "http://localhost:8081"
+          & setRequestMethod "POST"
+          & setRequestBodyLBS ("SELECT posts FROM posts WHERE posts.$fileName == \"" <> LB.fromString fileName <> "\"")
+      )
+
+updatePost :: String -> A.Value -> JSM (Either String ())
+updatePost fileName value =
+  A.eitherDecode
+    <$> fetch
+      ( fromString "http://localhost:8081"
+          & setRequestMethod "POST"
+          & setRequestBodyLBS ("UPDATE posts SET " <> A.encode value <> " WHERE posts.$fileName == \"" <> LB.fromString fileName <> "\"")
+      )
+
 fetch :: Request -> JSM LB.ByteString
 fetch req = LB.fromStrict . getResponseBody <$> httpBS req