{-# LANGUAGE OverloadedStrings #-}

module Auth where

import           API
import           Control.Monad.IO.Class
import qualified Data.ByteString.Char8     as BS
import qualified Data.Text                 as T
import           Data.Text.Encoding        (decodeUtf8)
import qualified Database.SQLite.Simple    as S
import           Servant
import           System.POSIX.Crypt.SHA512

initDB :: FilePath -> IO ()
initDB dbfile = S.withConnection dbfile $ \conn ->
    S.execute_ conn
        "CREATE TABLE IF NOT EXISTS users ( `id` INTEGER PRIMARY KEY AUTOINCREMENT\
                                         \, `email` TEXT NOT NULL\
                                         \, `password` TEXT NOT NULL\
                                         \)"

checkPassword :: String -> String -> Bool
checkPassword pass hashed =
    let pass' = (maybe "messed up" (T.unpack . decodeUtf8) $ cryptSHA512 (BS.pack pass) (BS.pack hashed))
    in
        pass' == hashed

checkBasicAuth :: FilePath -> BasicAuthCheck User
checkBasicAuth dbfile = BasicAuthCheck $ \basicAuthData ->
    let username = T.unpack $ decodeUtf8 (basicAuthUsername basicAuthData)
        password = T.unpack $ decodeUtf8 (basicAuthPassword basicAuthData)
        queryData = (S.Only username) :: (S.Only String)
    in
        liftIO . S.withConnection dbfile $ \conn -> do
            r <- S.query conn "SELECT id,email,password FROM users WHERE email = ?" queryData :: IO [(Int, String, String)]
            return $ case length r of
                0 -> BadPassword
                _ -> let (uID, uName, uHash) = head r in
                        if checkPassword password (drop 14 uHash)
                            then Authorized (User uID uName)
                            else BadPassword