42 lines
1.3 KiB
Haskell
42 lines
1.3 KiB
Haskell
{-# Language TypeApplications #-}
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{-# Language DataKinds #-}
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module Database.Book
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( def
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, insertBook
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, InsertBook(..)
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, usersBooks
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, Book(..)
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, BookID) where
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import ClassyPrelude
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import Database.Schema
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import Database
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import Database.Selda
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import Database.Selda.Generic
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usersBooks :: (MonadSelda m, MonadMask m, MonadIO m) => Username -> m [Book]
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usersBooks username = fromRels <$> query q
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where
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q = do
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userId :*: _ :*: username' :*: _ <- select (gen users)
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book@(_ :*: _ :*: _ :*: _ :*: _ :*: owner) <- select (gen books)
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restrict (username' .== literal username)
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restrict (userId .== owner)
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return book
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data InsertBook = InsertBook { contentType :: Text
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, title :: Maybe Text
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, description :: Maybe Text
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, owner :: Username }
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-- Always inserts
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insertBook :: (MonadSelda m, MonadMask m, MonadIO m) => InsertBook -> m (Maybe BookID)
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insertBook InsertBook{..} = do
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mUserId <- query $ do
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userId :*: _ :*: username' :*: _ <- select (gen users)
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restrict (username' .== literal owner)
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return userId
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forM (listToMaybe mUserId) $ \userId -> do
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let book = Book{owner=userId,identifier=def,contentHash=Nothing,..}
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BookID . fromRowId <$> insertGenWithPK books [book]
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