quotes-api/app/Main.hs

{-# LANGUAGE QuasiQuotes #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE DerivingStrategies #-}
{-# LANGUAGE DerivingVia #-}
{-# LANGUAGE StandaloneDeriving #-}
{-# LANGUAGE DeriveGeneric #-}
module Main where

import Data.Text (Text(..))
import Data.Aeson
import qualified MyLib (someFunc)
import Database.SQLite.Simple
import Database.SQLite.Simple.FromRow (FromRow)
import Database.SQLite.Simple.FromField (fromField)
import Database.SQLite.Simple.QQ
import Network.Wai
import Network.Wai.Handler.Warp
import Deriving.Aeson
import Data.Proxy
import Servant

import Control.Monad.IO.Class

data Quote = Quote { qQuote :: Text
                   , qAuthor :: Text
                   , qBook :: Text
                   } deriving (Show, Eq, Ord, Generic)
                     deriving (FromJSON,ToJSON)
                       via CustomJSON '[OmitNothingFields, FieldLabelModifier '[StripPrefix "q", CamelToSnake]] Quote

instance FromRow Quote where
  fromRow = Quote <$> field <*> field <*> field


main :: IO ()
main = do
  putStrLn "Hello, Haskell!"
  let dbfile = "quotes.db"
  initDb dbfile
  runApp dbfile


type API = Get '[JSON] [Quote]

api :: Proxy API
api = Proxy

initDb :: FilePath -> IO ()
initDb dbFile = withConnection dbFile $ \conn ->
  execute_ conn
    [sql|CREATE TABLE IF NOT EXISTS quotes (quote text non null, author text, book text)|]

server :: FilePath -> Server API
server dbf = listQuotes dbf


listQuotes :: FilePath -> Handler [Quote]
listQuotes db = liftIO $ withConnection db $ \conn -> query_ conn [sql|SELECT * FROM quotes;|]

runApp :: FilePath -> IO ()
runApp dbfile = run 8081 (serve api $ server dbfile)