Attach tags to books

Closes #8

src/Database/Book.hs

@@ -18,11 +18,13 @@ module Database.Book
   , BookID) where
 
 import ClassyPrelude
-import Database.Schema
+import Database.Schema (books, users, Username, Book(..), BookID(..), UserID, HashDigest(..))
 import Database
 import Database.Selda
 import Database.Selda.Generic
 
+import Database.Tag (attachTag)
+
 usersBooks :: (MonadSelda m, MonadMask m, MonadIO m) => Username -> m [Book]
 usersBooks username = fromRels <$> query q
   where
@@ -64,7 +66,8 @@ data UpdateBook = UpdateBook { identifier :: BookID
                              , contentType :: Text
                              , title :: Maybe Text
                              , description :: Maybe Text
-                             , owner :: Username }
+                             , owner :: Username
+                             , tags :: [Text]}
 
 bookExists :: (MonadSelda m, MonadMask m, MonadIO m) => BookID -> m Bool
 bookExists identifier = not . null <$> query q
@@ -88,13 +91,19 @@ bookOwner' identifier username = do
 
 updateBook :: (MonadSelda m, MonadMask m, MonadIO m) => UpdateBook -> m (Maybe UpdateBook)
 updateBook book@UpdateBook{..} = do
-  mUserId <- query (bookOwner' identifier owner)
-  forM (listToMaybe mUserId) $ \_userId -> do
-    update_ (gen books) predicate (\b -> b `with` [ pContentType := literal contentType
-                                                  , pTitle := literal title
-                                                  , pDescription := literal description ])
-    return book
+  connectChannels
+  connectTags
+  updateBook'
   where
+    connectTags = mapM_ (attachTag owner identifier) tags
+    connectChannels = return ()
+    updateBook' = do
+      mUserId <- query (bookOwner' identifier owner)
+      forM (listToMaybe mUserId) $ \_userId -> do
+        update_ (gen books) predicate (\b -> b `with` [ pContentType := literal contentType
+                                                      , pTitle := literal title
+                                                      , pDescription := literal description ])
+        return book
     _ :*: _ :*: pContentType :*: pTitle :*: pDescription :*: _ = selectors (gen books)
     predicate (bookId :*: _) = bookId .== literal identifier
 

src/Database/Tag.hs

@@ -17,9 +17,9 @@ import Database.Selda
 import Database.Selda.Generic
 
 upsertTag :: (MonadMask m, MonadIO m, MonadSelda m) => Username -> Text -> m Tag
-upsertTag username tag = transaction $ do
+upsertTag username tag = do
   -- I want this to error out if some data is invariant is wrong and roll back
-  -- the transaction
+  -- the transaction. Also as a side note, run this in a transaction plz
   [userId] <- query userQ
   void $ upsert (gen tags) (predicate userId) id [toRel (Tag def tag userId)]
   [t] <- fromRels <$> query (tagQ userId)
@@ -46,9 +46,9 @@ booksTags bookId = fromRels <$> query q
       return tag
 
 attachTag :: (MonadMask m, MonadIO m, MonadSelda m) => Username -> BookID -> Text -> m ()
-attachTag username bookId tag = transaction $ do
+attachTag username bookId tag = do
   Tag{identifier} <- upsertTag username tag
-  unlessM (null <$> query (tagQ identifier)) $
+  whenM (null <$> query (tagQ identifier)) $
     void $ insertGen bookTags [BookTag identifier bookId]
   where
     tagQ tagId = do