{-# LANGUAGE DataKinds             #-}
{-# LANGUAGE FlexibleInstances     #-}
{-# LANGUAGE QuasiQuotes           #-}
{-# LANGUAGE TemplateHaskell       #-}


module GHCup.Platform where


import           GHCup.Errors
import           GHCup.Types
import           GHCup.Types.JSON               ( )
import           GHCup.Utils.Bash
import           GHCup.Utils.File
import           GHCup.Utils.Prelude
import           GHCup.Utils.String.QQ

import           Control.Applicative
import           Control.Exception.Safe
import           Control.Monad
import           Control.Monad.Logger
import           Control.Monad.Reader
import           Control.Monad.Trans.Class      ( lift )
import           Data.Foldable
import           Data.Maybe
import           Data.String.Interpolate
import           Data.Text                      ( Text )
import           Data.Versions
import           HPath
import           HPath.IO
import           Haskus.Utils.Variant.Excepts
import           Prelude                 hiding ( abs
                                                , readFile
                                                , writeFile
                                                )
import           System.Info

import qualified Data.Text                     as T
import qualified Data.Text.Encoding            as E
import qualified Data.Text.ICU                 as ICU

    --------------------------
    --[ Platform detection ]--
    --------------------------


getArchitecture :: Either NoCompatibleArch Architecture
getArchitecture = case arch of
  "x86_64" -> Right A_64
  "i386"   -> Right A_32
  what     -> Left (NoCompatibleArch what)



getPlatform :: (MonadLogger m, MonadCatch m, MonadIO m)
            => Excepts
                 '[NoCompatiblePlatform , DistroNotFound]
                 m
                 PlatformResult
getPlatform = do
  pfr <- case os of
    "linux" -> do
      (distro, ver) <- liftE getLinuxDistro
      pure $ PlatformResult { _platform = Linux distro, _distroVersion = ver }
    -- TODO: these are not verified
    "darwin" ->
      pure $ PlatformResult { _platform = Darwin, _distroVersion = Nothing }
    "freebsd" -> do
      ver <- getFreeBSDVersion
      pure $ PlatformResult { _platform = FreeBSD, _distroVersion = ver }
    what -> throwE $ NoCompatiblePlatform what
  lift $ $(logDebug) [i|Identified Platform as: #{pfr}|]
  pure pfr
  where getFreeBSDVersion = pure Nothing


getLinuxDistro :: (MonadCatch m, MonadIO m)
               => Excepts '[DistroNotFound] m (LinuxDistro, Maybe Versioning)
getLinuxDistro = do
  -- TODO: don't do alternative on IO, because it hides bugs
  (name, ver) <- handleIO (\_ -> throwE DistroNotFound) $ liftIO $ asum
    [ try_os_release
    , try_lsb_release_cmd
    , try_lsb_release
    , try_redhat_release
    , try_debian_version
    ]
  let parsedVer = ver >>= either (const Nothing) Just . versioning
      distro    = if
        | hasWord name ["debian"]  -> Debian
        | hasWord name ["ubuntu"]  -> Ubuntu
        | hasWord name ["linuxmint", "Linux Mint"] -> Mint
        | hasWord name ["fedora"]  -> Fedora
        | hasWord name ["centos"]  -> CentOS
        | hasWord name ["Red Hat"] -> RedHat
        | hasWord name ["alpine"]  -> Alpine
        | hasWord name ["exherbo"] -> Exherbo
        | hasWord name ["gentoo"]  -> Gentoo
        | hasWord name ["amazonlinux", "Amazon Linux"] -> AmazonLinux
        | otherwise                -> UnknownLinux
  pure (distro, parsedVer)
 where
  hasWord t matches = foldr
    (\x y ->
      ( isJust
        . ICU.find (ICU.regex [ICU.CaseInsensitive] ([s|\b|] <> x <> [s|\b|]))
        $ t
        )
        || y
    )
    False
    (T.pack <$> matches)

  os_release :: Path Abs
  os_release = [abs|/etc/os-release|]
  lsb_release :: Path Abs
  lsb_release = [abs|/etc/lsb-release|]
  lsb_release_cmd :: Path Rel
  lsb_release_cmd = [rel|lsb-release|]
  redhat_release :: Path Abs
  redhat_release = [abs|/etc/redhat-release|]
  debian_version :: Path Abs
  debian_version = [abs|/etc/debian_version|]

  try_os_release :: IO (Text, Maybe Text)
  try_os_release = do
    (Just name) <- getAssignmentValueFor os_release "NAME"
    ver         <- getAssignmentValueFor os_release "VERSION_ID"
    pure (T.pack name, fmap T.pack ver)

  try_lsb_release_cmd :: IO (Text, Maybe Text)
  try_lsb_release_cmd = do
    (Just _) <- findExecutable lsb_release_cmd
    name     <- fmap _stdOut $ executeOut lsb_release_cmd [[s|-si|]] Nothing
    ver      <- fmap _stdOut $ executeOut lsb_release_cmd [[s|-sr|]] Nothing
    pure (E.decodeUtf8 name, Just $ E.decodeUtf8 ver)

  try_lsb_release :: IO (Text, Maybe Text)
  try_lsb_release = do
    (Just name) <- getAssignmentValueFor lsb_release "DISTRIB_ID"
    ver         <- getAssignmentValueFor lsb_release "DISTRIB_RELEASE"
    pure (T.pack name, fmap T.pack ver)

  try_redhat_release :: IO (Text, Maybe Text)
  try_redhat_release = do
    t <- fmap lBS2sT $ readFile redhat_release
    let nameRe n =
          join
            . fmap (ICU.group 0)
            . ICU.find
                (ICU.regex [ICU.CaseInsensitive] ([s|\b|] <> fS n <> [s|\b|]))
            $ t
        verRe =
          join
            . fmap (ICU.group 0)
            . ICU.find
                (ICU.regex [ICU.CaseInsensitive] [s|\b(\d)+(.(\d)+)*\b|])
            $ t
    (Just name) <- pure
      (nameRe "CentOS" <|> nameRe "Fedora" <|> nameRe "Red Hat")
    pure (name, verRe)

  try_debian_version :: IO (Text, Maybe Text)
  try_debian_version = do
    ver <- readFile debian_version
    pure (T.pack "debian", Just $ lBS2sT ver)