--  pi-hoole: lightweight access-control for pijul
--  Copyright (C) 2018 Thomas Letan <contact@thomasletan.fr>
--
--  This program is free software: you can redistribute it and/or modify
--  it under the terms of the GNU Affero General Public License as published
--  by the Free Software Foundation, either version 3 of the License, or
--  (at your option) any later version.
--
--  This program is distributed in the hope that it will be useful,
--  but WITHOUT ANY WARRANTY; without even the implied warranty of
--  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--  GNU Affero General Public License for more details.
--
--  You should have received a copy of the GNU Affero General Public License
--  along with this program.  If not, see <http://www.gnu.org/licenses/>.

{-# LANGUAGE LambdaCase        #-}
{-# LANGUAGE OverloadedStrings #-}

module Main where

import           Control.Monad      (void)
import           Data.Map.Strict    (Map)
import qualified Data.Map.Strict    as M (fromList, traverseWithKey)
import           Data.Set           (Set)
import qualified Data.Set           as S (fromList)
import           Data.Text          (Text, append, pack, unpack)
import qualified Data.Text.IO       as T (getLine)
import           Data.Void          (Void)
import           Data.Yaml          (decodeFile)
import           PiHoole
import           System.Directory   (XdgDirectory (..), getXdgDirectory)
import           System.Environment (getArgs)
import           Text.Megaparsec    (parseTest)

-------------------------------------------------------------------------------
main :: IO ()
main = getConfiguration >>= \case
  Just cfg -> getArgs >>= \case
    [ "--license" ] ->
      putStrLn license
    [ user, "" ] ->
      case parseUserName (pack user) of
        Just user@(UserName username) -> do
          putStrLn $ "Connected as " ++ unpack username ++ "\n"
          printPrivileges (hasPrivileges (User user) cfg)
          putStrLn ""
    [ user, cmd ] ->
      case (parseUserName (pack user), parsePijul (pack cmd)) of
        (Just user, Just cmd) ->
          pijulProxy cfg user cmd
        (Nothing, _) ->
          putStrLn $ user ++ " is not a valid role"
        (_, Nothing) ->
          putStrLn $ cmd ++ " is not a valid pijul command"
    _ ->
      putStrLn "incorrect shell command"
  Nothing ->
    putStrLn "could not parse the configuration file"


-------------------------------------------------------------------------------

-------------------------------------------------------------------------------
printPrivileges :: Map Repo Privilege -> IO ()
printPrivileges map = void $ M.traverseWithKey printPrivilege map
  where
   printPrivilege (Repo repo) priv =
     putStrLn $ "- " ++ repo ++ ": " ++ unpack (privilegeToText priv)

getConfiguration :: IO (Maybe Configuration)
getConfiguration = getXdgDirectory XdgConfig "pi-hoole/config.yaml" >>= decodeFile

decodeLimes :: FilePath -> IO (Maybe Configuration)
decodeLimes = decodeFile

pijulProxy :: Configuration -> UserName -> Pijul -> IO ()
pijulProxy cfg user cmd
  | checkPrivilege user cmd cfg =  callPijul cmd
  | otherwise = putStrLn "nah"

license :: String
license =
  unlines [ "Copyright (C) 2018 Thomas Letan <contact@thomasletan.fr>"
          , ""
          , "This program is free software: you can redistribute it and/or modify"
          , "it under the terms of the GNU Affero General Public License as published"
          , "by the Free Software Foundation, either version 3 of the License, or"
          , "(at your option) any later version."
          , ""
          , "This program is distributed in the hope that it will be useful,"
          , "but WITHOUT ANY WARRANTY; without even the implied warranty of"
          , "MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the"
          , "GNU Affero General Public License for more details."
          , ""
          , "You should have received a copy of the GNU Affero General Public License"
          , "along with this program.  If not, see <http://www.gnu.org/licenses/>."
          ]
-------------------------------------------------------------------------------