{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE QuasiQuotes #-}

module Main where

import Data.Functor.Contravariant (contramap)
import Data.Int (Int64)
import Data.Text (Text)
import qualified Hasql.Decoders as Decoders
import Hasql.Decoders (Row)
import qualified Hasql.Encoders as Encoders
import Hasql.Encoders (Params, Value)
import Hasql.Statement (Statement(Statement))
import qualified Hasql.Statement as Hasql
import Prelude hiding (id)
import Text.RawString.QQ (r)

data User = User
  { id :: Int
  , password :: Text
  , email :: Text
  , username :: Text
  , bio :: Text
  , image :: Maybe Text
  }

userParams :: Params User
userParams =
  contramap (fromIntegral . id) (Encoders.param Encoders.int8) <>
  contramap password (Encoders.param Encoders.text) <>
  contramap email (Encoders.param Encoders.text) <>
  contramap username (Encoders.param Encoders.text) <>
  contramap bio (Encoders.param Encoders.text) <>
  contramap image (Encoders.nullableParam Encoders.text)

userRow :: Row User
userRow =
  User
    <$> (fromIntegral <$> Decoders.column Decoders.int8)
    <*> Decoders.column Decoders.text
    <*> Decoders.column Decoders.text
    <*> Decoders.column Decoders.text
    <*> Decoders.column Decoders.text
    <*> Decoders.nullableColumn Decoders.text

selectAllUsers :: Statement () [User]
selectAllUsers = Statement sql encoder decoder True
  where
    sql =
      [r|
        select
          id,
          password,
          email,
          username,
          bio,
          image
        from users
      |]
    encoder = Encoders.unit
    decoder = Decoders.rowList userRow

main :: IO ()
main = putStrLn "Hello, Haskell!"