{-# LANGUAGE CPP              #-}
{-# LANGUAGE DataKinds        #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE QuasiQuotes      #-}
{-# LANGUAGE TemplateHaskell  #-}
{-# LANGUAGE TypeApplications #-}
{-# LANGUAGE ViewPatterns     #-}
{-# LANGUAGE OverloadedStrings #-}

module Generate where

import           GHCup
import           GHCup.Download
import           GHCup.Errors
import           GHCup.Types
import           GHCup.Types.Optics
import           GHCup.Utils


import           Codec.Archive
import           Control.Exception.Safe      hiding ( handle )
import           Control.Monad
import           Control.Monad.IO.Class
import           Control.Monad.Reader.Class
import           Control.Monad.Trans.Resource   ( runResourceT
                                                , MonadUnliftIO
                                                )
import qualified Data.Aeson.Encode.Pretty     as Aeson
import           Data.ByteString                ( ByteString )
import           Data.Either
import           Data.Maybe
import           Data.List
import           Data.Map.Strict                ( Map )
import           Data.Versions
import           Haskus.Utils.Variant.Excepts
import           System.Exit
import           System.IO
import           Text.Regex.Posix
import           GHCup.Utils.String.QQ

import qualified Data.ByteString.Lazy          as BSL
import qualified Data.Map.Strict               as M
import qualified Data.Text                     as T
import qualified Data.Yaml.Pretty              as YAML
import qualified Text.Megaparsec               as MP

data Format = FormatJSON
            | FormatYAML

data Output
  = FileOutput FilePath -- optsparse-applicative doesn't handle ByteString correctly anyway
  | StdOut

type HlsGhcVersions = Map Version (Map Architecture (Map Platform Version))

generateHLSGhc :: ( MonadFail m
                  , MonadMask m
                  , Monad m
                  , MonadReader env m
                  , HasSettings env
                  , HasDirs env
                  , HasLog env
                  , MonadThrow m
                  , MonadIO m
                  , MonadUnliftIO m
                  , HasGHCupInfo env
                  )
               => Format
               -> Output
               -> m ExitCode
generateHLSGhc format output = do
  GHCupInfo { _ghcupDownloads = dls } <- getGHCupInfo
  let hlses = dls M.! HLS
  r <- forM hlses $ \(_viArch -> archs) ->
         forM archs $ \plats ->
           forM plats $ \(head . M.toList -> (_, dli)) -> do
             VRight r <- runResourceT . runE
                    @'[DigestError
                      , GPGError
                      , DownloadFailed
                      , UnknownArchive
                      , ArchiveResult
                      ] $ do
               fp <- liftE $ downloadCached dli Nothing
               files <- liftE $ getArchiveFiles fp
               let regex = makeRegexOpts compExtended execBlank ([s|^haskell-language-server-([0-9]+\.)*([0-9]+)$|] :: ByteString)
               let ghcs = rights $ MP.parse version' ""
                                 . T.pack
                                 . fromJust
                                 . stripPrefix "haskell-language-server-"
                                <$> filter (match regex) files
               pure ghcs
             pure r
  let w = case format of
            FormatYAML -> BSL.fromStrict $ YAML.encodePretty YAML.defConfig r
            FormatJSON -> Aeson.encodePretty r
  case output of
    StdOut -> liftIO $ BSL.putStr w
    FileOutput f -> liftIO $ BSL.writeFile f w
  pure ExitSuccess


generateTable :: ( MonadFail m
                 , MonadMask m
                 , Monad m
                 , MonadReader env m
                 , HasSettings env
                 , HasDirs env
                 , HasLog env
                 , MonadThrow m
                 , MonadIO m
                 , HasPlatformReq env
                 , HasGHCupInfo env
                 , MonadUnliftIO m
                 )
              => Output
              -> m ExitCode
generateTable output = do
  handle <- case output of
              StdOut -> pure stdout
              FileOutput fp -> liftIO $ openFile fp WriteMode
              
  forM_ [GHC,Cabal,HLS,Stack] $ \tool -> do
    liftIO $ hPutStrLn handle $ "<table>"
    liftIO $ hPutStrLn handle $ "<thead><tr><th>" <> show tool <> " Version</th><th>Tags</th></tr></thead>"
    liftIO $ hPutStrLn handle $ "<tbody>"
    vers <- listVersions (Just tool) Nothing
    forM_ (filter (\ListResult{..} -> not lStray) vers) $ \ListResult{..} -> do
      liftIO $ hPutStrLn handle $
          "<tr><td>"
        <> T.unpack (prettyVer lVer)
        <> "</td><td>"
        <> intercalate ", " (filter (/= "") . fmap printTag $ sort lTag)
        <> "</td></tr>"
      pure ()
    liftIO $ hPutStrLn handle $ "</tbody>"
    liftIO $ hPutStrLn handle $ "</table>"
    liftIO $ hPutStrLn handle $ ""
  pure ExitSuccess
 where
  printTag Recommended        = "<span style=\"color:green\">recommended</span>"
  printTag Latest             = "<span style=\"color:blue\">latest</span>"
  printTag Prerelease         = "<span style=\"color:red\">prerelease</span>"
  printTag (Base       pvp'') = "base-" ++ T.unpack (prettyPVP pvp'')
  printTag (UnknownTag t    ) = t
  printTag Old                = ""