{-# LANGUAGE DataKinds           #-}
{-# LANGUAGE OverloadedStrings   #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TupleSections       #-}
{-# LANGUAGE TypeApplications    #-}

module App.Commands.SyncFromArchive
  ( cmdSyncFromArchive
  ) where

import Antiope.Core                     (runResAws, toText)
import Antiope.Env                      (mkEnv)
import App.Commands.Options.Parser      (optsSyncFromArchive)
import Control.Lens                     hiding ((<.>))
import Control.Monad                    (unless, void, when)
import Control.Monad.Catch              (MonadCatch)
import Control.Monad.Except
import Control.Monad.IO.Class           (liftIO)
import Data.ByteString.Lazy.Search      (replace)
import Data.Generics.Product.Any        (the)
import Data.Maybe
import Data.Semigroup                   ((<>))
import HaskellWorks.CabalCache.AppError
import HaskellWorks.CabalCache.IO.Error (exceptWarn, maybeToExcept)
import HaskellWorks.CabalCache.Location ((<.>), (</>))
import HaskellWorks.CabalCache.Metadata (loadMetadata)
import HaskellWorks.CabalCache.Show
import HaskellWorks.CabalCache.Version  (archiveVersion)
import Options.Applicative              hiding (columns)
import System.Directory                 (createDirectoryIfMissing, doesDirectoryExist)

import qualified App.Commands.Options.Types                       as Z
import qualified Control.Concurrent.STM                           as STM
import qualified Data.ByteString.Char8                            as C8
import qualified Data.ByteString.Lazy                             as LBS
import qualified Data.Map                                         as M
import qualified Data.Map.Strict                                  as Map
import qualified Data.Text                                        as T
import qualified HaskellWorks.CabalCache.AWS.Env                  as AWS
import qualified HaskellWorks.CabalCache.Concurrent.DownloadQueue as DQ
import qualified HaskellWorks.CabalCache.Concurrent.Fork          as IO
import qualified HaskellWorks.CabalCache.Core                     as Z
import qualified HaskellWorks.CabalCache.GhcPkg                   as GhcPkg
import qualified HaskellWorks.CabalCache.Hash                     as H
import qualified HaskellWorks.CabalCache.IO.Console               as CIO
import qualified HaskellWorks.CabalCache.IO.Lazy                  as IO
import qualified HaskellWorks.CabalCache.IO.Tar                   as IO
import qualified HaskellWorks.CabalCache.Types                    as Z
import qualified System.Directory                                 as IO
import qualified System.IO                                        as IO
import qualified System.IO.Temp                                   as IO
import qualified System.IO.Unsafe                                 as IO

{-# ANN module ("HLint: ignore Reduce duplication"  :: String) #-}
{-# ANN module ("HLint: ignore Redundant do"        :: String) #-}

skippable :: Z.Package -> Bool
skippable package = (package ^. the @"packageType" == "pre-existing")

runSyncFromArchive :: Z.SyncFromArchiveOptions -> IO ()
runSyncFromArchive opts = do
  let storePath           = opts ^. the @"storePath"
  let archiveUri          = opts ^. the @"archiveUri"
  let threads             = opts ^. the @"threads"
  let awsLogLevel         = opts ^. the @"awsLogLevel"
  let versionedArchiveUri = archiveUri </> archiveVersion
  let storePathHash       = opts ^. the @"storePathHash" & fromMaybe (H.hashStorePath storePath)
  let scopedArchiveUri    = versionedArchiveUri </> T.pack storePathHash

  CIO.putStrLn $ "Store path: "       <> toText storePath
  CIO.putStrLn $ "Store path hash: "  <> T.pack storePathHash
  CIO.putStrLn $ "Archive URI: "      <> toText archiveUri
  CIO.putStrLn $ "Archive version: "  <> archiveVersion
  CIO.putStrLn $ "Threads: "          <> tshow threads
  CIO.putStrLn $ "AWS Log level: "    <> tshow awsLogLevel

  GhcPkg.testAvailability

  mbPlan <- Z.loadPlan
  case mbPlan of
    Right planJson -> do
      envAws <- IO.unsafeInterleaveIO $ mkEnv (opts ^. the @"region") (AWS.awsLogger awsLogLevel)
      let compilerId                  = planJson ^. the @"compilerId"
      let storeCompilerPath           = storePath </> T.unpack compilerId
      let storeCompilerPackageDbPath  = storeCompilerPath </> "package.db"
      let storeCompilerLibPath        = storeCompilerPath </> "lib"

      CIO.putStrLn "Creating store directories"
      createDirectoryIfMissing True storePath
      createDirectoryIfMissing True storeCompilerPath
      createDirectoryIfMissing True storeCompilerLibPath

      storeCompilerPackageDbPathExists <- doesDirectoryExist storeCompilerPackageDbPath

      unless storeCompilerPackageDbPathExists $ do
        CIO.putStrLn "Package DB missing. Creating Package DB"
        GhcPkg.init storeCompilerPackageDbPath

      packages <- Z.getPackages storePath planJson

      let installPlan = planJson ^. the @"installPlan"
      let planPackages = M.fromList $ fmap (\p -> (p ^. the @"id", p)) installPlan

      let planDeps0 = installPlan >>= \p -> fmap (p ^. the @"id", ) $ mempty
            <> (p ^. the @"depends")
            <> (p ^. the @"exeDepends")
            <> (p ^.. the @"components" . each . the @"lib" . each . the @"depends"    . each)
            <> (p ^.. the @"components" . each . the @"lib" . each . the @"exeDepends" . each)
      let planDeps  = planDeps0 <> fmap (\p -> ("[universe]", p ^. the @"id")) installPlan

      downloadQueue <- STM.atomically $ DQ.createDownloadQueue planDeps

      let pInfos = M.fromList $ fmap (\p -> (p ^. the @"packageId", p)) packages

      -- forM_ planDeps $ \(a, b) -> do
      --   let maybeName = M.lookup a planPackages <&> (^. the @"name")
      --   case maybeName of
      --     Just name -> CIO.putStrLn $ name <> " " <> a <> " -> " <> b
      --     Nothing   -> CIO.putStrLn $ "*********" <> a <> " -> " <> b

      IO.withSystemTempDirectory "cabal-cache" $ \tempPath -> do
        IO.createDirectoryIfMissing True (tempPath </> T.unpack compilerId </> "package.db")

        IO.forkThreadsWait threads $ DQ.runQueue downloadQueue $ \packageId -> case M.lookup packageId pInfos of
          Just pInfo -> do
            let archiveBaseName   = Z.packageDir pInfo <.> ".tar.gz"
            let archiveFile       = versionedArchiveUri </> T.pack archiveBaseName
            let scopedArchiveFile = scopedArchiveUri </> T.pack archiveBaseName
            let packageStorePath  = storePath </> Z.packageDir pInfo
            storeDirectoryExists <- doesDirectoryExist packageStorePath
            let maybePackage = M.lookup packageId planPackages

            case maybePackage of
              Nothing -> do
                CIO.hPutStrLn IO.stderr $ "Warning: package not found" <> packageId
                return True
              Just package -> if skippable package
                then do
                  CIO.putStrLn $ "Skipping: " <> packageId
                  return True
                else if storeDirectoryExists
                  then return True
                  else runResAws envAws $ onError (cleanupStorePath packageStorePath packageId) False $ do
                    (existingArchiveFileContents, existingArchiveFile) <- ExceptT $ IO.readFirstAvailableResource envAws [scopedArchiveFile, archiveFile]
                    CIO.putStrLn $ "Extracting: " <> toText existingArchiveFile

                    let tempArchiveFile = tempPath </> archiveBaseName
                    liftIO $ LBS.writeFile tempArchiveFile existingArchiveFileContents
                    IO.extractTar tempArchiveFile storePath

                    meta <- loadMetadata packageStorePath
                    oldStorePath <- maybeToExcept "store-path is missing from Metadata" (Map.lookup "store-path" meta)

                    case Z.confPath pInfo of
                      Z.Tagged conf _ -> do
                        let theConfPath = storePath </> conf
                        let tempConfPath = tempPath </> conf
                        confPathExists <- liftIO $ IO.doesFileExist theConfPath
                        when confPathExists $ do
                          confContents <- liftIO $ LBS.readFile theConfPath
                          liftIO $ LBS.writeFile tempConfPath (replace (LBS.toStrict oldStorePath) (C8.pack storePath) confContents)
                          liftIO $ IO.renamePath tempConfPath theConfPath
                        return True
          Nothing -> do
            CIO.hPutStrLn IO.stderr $ "Warning: Invalid package id: " <> packageId
            return True

      CIO.putStrLn "Recaching package database"
      GhcPkg.recache storeCompilerPackageDbPath

      failures <- STM.atomically $ STM.readTVar $ downloadQueue ^. the @"tFailures"

      forM_ failures $ \packageId -> CIO.hPutStrLn IO.stderr $ "Failed to download: " <> packageId

    Left appError -> do
      CIO.hPutStrLn IO.stderr $ "ERROR: Unable to parse plan.json file: " <> displayAppError appError

  return ()

cleanupStorePath :: (MonadIO m, MonadCatch m) => FilePath -> Z.PackageId -> AppError -> m ()
cleanupStorePath packageStorePath packageId e = do
  CIO.hPutStrLn IO.stderr $ "Warning: Sync failure: " <> packageId <> ", reason: " <> displayAppError e
  void $ IO.removePathRecursive packageStorePath

onError :: MonadIO m => (AppError -> m ()) -> a -> ExceptT AppError m a -> m a
onError h failureValue f = do
  result <- runExceptT $ catchError (exceptWarn f) handler
  case result of
    Left _  -> return failureValue
    Right a -> return a
  where handler e = lift (h e) >> return failureValue

cmdSyncFromArchive :: Mod CommandFields (IO ())
cmdSyncFromArchive = command "sync-from-archive"  $ flip info idm $ runSyncFromArchive <$> optsSyncFromArchive