module Handlers where

import Core
import Database
import Logger

import qualified Data.ByteString.Char8    as C
import Data.List
import qualified Data.Text                as T
import Effectful
import Effectful.Error.Static             (Error, throwError)
import Effectful.FileSystem
import Effectful.FileSystem.IO.ByteString as EBS
import Servant hiding                     ((:>), throwError)
import qualified Servant                  as S

type CRUD es = ( Database :> es, Logger :> es, Error ServerError :> es )

rootHandler :: (Logger :> es, Error ServerError :> es) => Eff es T.Text
rootHandler = (writeLog Info "Hit the root!") >>= \_ ->
  return "Hello, World!"

userListHandler :: CRUD es => Eff es [User]
userListHandler = (writeLog Info "Selected all users!") >>= \_ -> 
  databaseRead_ "SELECT id, name FROM users"

userGetHandler :: CRUD es => UserId -> Eff es User
userGetHandler userId = databaseRead (queryUser userId) >>= \mUser ->
  case mUser of
    (a:_) -> pure a
    []    -> pure (User (UserId 0) "No user found")

userPostHandler :: CRUD es => T.Text -> Eff es NoContent
userPostHandler name =
  databaseWrite (writeUser name) >>= \_ -> return NoContent

userDeleteHandler :: CRUD es => UserId -> Eff es NoContent
userDeleteHandler userId =
  databaseWrite (deleteUser userId) >>= \_ -> return NoContent