{-# LANGUAGE ScopedTypeVariables #-}

-- | Effectful functions that create and convert disk image files.
module B9.DiskImageBuilder
  ( materializeImageSource,
    substImageTarget,
    preferredDestImageTypes,
    preferredSourceImageTypes,
    resolveImageSource,
    createDestinationImage,
    resizeImage,
    importImage,
    exportImage,
    exportAndRemoveImage,
    convertImage,
    shareImage,
    ensureAbsoluteImageDirExists,
  )
where

import B9.Artifact.Content.StringTemplate
import B9.B9Config
import B9.B9Error
import B9.B9Exec
import B9.B9Logging
import B9.B9Monad
import B9.BuildInfo
import B9.DiskImages
import B9.Environment
import qualified B9.PartitionTable as P
import B9.RepositoryIO
import Control.Eff
import qualified Control.Exception as IO
import Control.Lens ((^.))
import Control.Monad
import Control.Monad.IO.Class
import Data.Generics.Aliases
import Data.Generics.Schemes
import Data.List
import Data.Maybe
import qualified Foreign.C.Error as IO
import qualified GHC.IO.Exception as IO
import GHC.Stack
import System.Directory
import System.FilePath
import System.IO.B9Extras
  ( ensureDir,
    prettyPrintToFile,
  )
import Text.Printf (printf)
import Text.Show.Pretty (ppShow)

-- -- | Convert relative file paths of images, sources and mounted host directories
-- -- to absolute paths relative to '_projectRoot'.
-- makeImagePathsAbsoluteToBuildDirRoot :: ImageTarget -> B9 ImageTarget
-- makeImagePathsAbsoluteToBuildDirRoot img =
--   getConfig >>= maybe (return img) (return . go) . _projectRoot
--   where
--     go rootDir = everywhere mkAbs img
--       where mkAbs = mkT

-- | Replace $... variables inside an 'ImageTarget'
substImageTarget ::
  forall e.
  (HasCallStack, Member EnvironmentReader e, Member ExcB9 e) =>
  ImageTarget ->
  Eff e ImageTarget
substImageTarget = everywhereM gsubst
  where
    gsubst :: GenericM (Eff e)
    gsubst =
      mkM substMountPoint `extM` substImage `extM` substImageSource
        `extM` substDiskTarget
    substMountPoint NotMounted = pure NotMounted
    substMountPoint (MountPoint x) = MountPoint <$> substStr x
    substImage (Image fp t fs) = Image <$> substStr fp <*> pure t <*> pure fs
    substImageSource (From n s) = From <$> substStr n <*> pure s
    substImageSource (EmptyImage l f t s) =
      EmptyImage <$> substStr l <*> pure f <*> pure t <*> pure s
    substImageSource s = pure s
    substDiskTarget (Share n t s) = Share <$> substStr n <*> pure t <*> pure s
    substDiskTarget (LiveInstallerImage name outDir resize) =
      LiveInstallerImage <$> substStr name <*> substStr outDir <*> pure resize
    substDiskTarget s = pure s

-- | Resolve an ImageSource to an 'Image'. The ImageSource might
-- not exist, as is the case for 'EmptyImage'.
resolveImageSource :: IsB9 e => ImageSource -> Eff e Image
resolveImageSource src =
  case src of
    (EmptyImage fsLabel fsType imgType _size) ->
      let img = Image fsLabel imgType fsType
       in return (changeImageFormat imgType img)
    (SourceImage srcImg _part _resize) -> ensureAbsoluteImageDirExists srcImg
    (CopyOnWrite backingImg) -> ensureAbsoluteImageDirExists backingImg
    (From name _resize) ->
      getLatestImageByName (SharedImageName name)
        >>= maybe
          ( errorExitL
              (printf "Nothing found for %s." (show (SharedImageName name)))
          )
          ensureAbsoluteImageDirExists

-- | Return all valid image types sorted by preference.
preferredDestImageTypes :: IsB9 e => ImageSource -> Eff e [ImageType]
preferredDestImageTypes src =
  case src of
    (CopyOnWrite (Image _file fmt _fs)) -> return [fmt]
    (EmptyImage _label NoFileSystem fmt _size) ->
      return (nub [fmt, Raw, QCow2, Vmdk])
    (EmptyImage _label _fs _fmt _size) -> return [Raw]
    (SourceImage _img (Partition _) _resize) -> return [Raw]
    (SourceImage (Image _file fmt _fs) _pt resize) ->
      return
        ( nub [fmt, Raw, QCow2, Vmdk]
            `intersect` allowedImageTypesForResize resize
        )
    (From name resize) ->
      getLatestImageByName (SharedImageName name)
        >>= maybe
          ( errorExitL
              (printf "Nothing found for %s." (show (SharedImageName name)))
          )
          ( \sharedImg ->
              preferredDestImageTypes (SourceImage sharedImg NoPT resize)
          )

-- | Return all supported source 'ImageType's compatible to a 'ImageDestinaion'
-- in the preferred order.
preferredSourceImageTypes :: HasCallStack => ImageDestination -> [ImageType]
preferredSourceImageTypes dest =
  case dest of
    (Share _ fmt resize) ->
      nub [fmt, Raw, QCow2, Vmdk] `intersect` allowedImageTypesForResize resize
    (LocalFile (Image _ fmt _) resize) ->
      nub [fmt, Raw, QCow2, Vmdk] `intersect` allowedImageTypesForResize resize
    Transient -> [Raw, QCow2, Vmdk]
    (LiveInstallerImage _name _repo _imgResize) -> [Raw]

allowedImageTypesForResize :: HasCallStack => ImageResize -> [ImageType]
allowedImageTypesForResize r =
  case r of
    Resize _ -> [Raw]
    ShrinkToMinimumAndIncrease _ -> [Raw]
    ShrinkToMinimum -> [Raw]
    ResizeImage _ -> [Raw, QCow2, Vmdk]
    KeepSize -> [Raw, QCow2, Vmdk]

-- | Create the parent directories for the file that contains the 'Image'.
-- If the path to the image file is relative, prepend '_projectRoot' from
-- the 'B9Config'.
ensureAbsoluteImageDirExists :: IsB9 e => Image -> Eff e Image
ensureAbsoluteImageDirExists img@(Image path _ _) = do
  b9cfg <- getConfig
  let dir =
        let dirRel = takeDirectory path
         in if isRelative dirRel
              then
                let prefix = fromMaybe "." (b9cfg ^. projectRoot)
                 in prefix </> dirRel
              else dirRel
  liftIO $ do
    createDirectoryIfMissing True dir
    dirAbs <- canonicalizePath dir
    return $ changeImageDirectory dirAbs img

-- | Create an image from an image source. The destination image must have a
-- compatible image type and filesystem. The directory of the image MUST be
-- present and the image file itself MUST NOT alredy exist.
materializeImageSource :: IsB9 e => ImageSource -> Image -> Eff e ()
materializeImageSource src dest =
  case src of
    (EmptyImage fsLabel fsType _imgType size) ->
      let (Image _ imgType _) = dest
       in createEmptyImage fsLabel fsType imgType size dest
    (SourceImage srcImg part resize) ->
      createImageFromImage srcImg part resize dest
    (CopyOnWrite backingImg) -> createCOWImage backingImg dest
    (From name resize) ->
      getLatestImageByName (SharedImageName name)
        >>= maybe
          ( errorExitL
              (printf "Nothing found for %s." (show (SharedImageName name)))
          )
          ( \sharedImg ->
              materializeImageSource (SourceImage sharedImg NoPT resize) dest
          )

createImageFromImage ::
  IsB9 e => Image -> Partition -> ImageResize -> Image -> Eff e ()
createImageFromImage src part size out = do
  importImage src out
  extractPartition part out
  resizeImage size out
  where
    extractPartition :: IsB9 e => Partition -> Image -> Eff e ()
    extractPartition NoPT _ = return ()
    extractPartition (Partition partIndex) (Image outFile Raw _) = do
      (start, len, blockSize) <- liftIO (P.getPartition partIndex outFile)
      let tmpFile = outFile <.> "extracted"
      dbgL (printf "Extracting partition %i from '%s'" partIndex outFile)
      cmd
        ( printf
            "dd if='%s' of='%s' bs=%i skip=%i count=%i &> /dev/null"
            outFile
            tmpFile
            blockSize
            start
            len
        )
      cmd (printf "mv '%s' '%s'" tmpFile outFile)
    extractPartition (Partition partIndex) (Image outFile fmt _) =
      error
        ( printf
            "Extract partition %i from image '%s': Invalid format %s"
            partIndex
            outFile
            (imageFileExtension fmt)
        )

-- | Convert some 'Image', e.g. a temporary image used during the build phase
-- to the final destination.
createDestinationImage :: IsB9 e => Image -> ImageDestination -> Eff e ()
createDestinationImage buildImg dest =
  case dest of
    (Share name imgType imgResize) -> do
      resizeImage imgResize buildImg
      let shareableImg = changeImageFormat imgType buildImg
      exportAndRemoveImage buildImg shareableImg
      void (shareImage shareableImg (SharedImageName name))
    (LocalFile destImg imgResize) -> do
      resizeImage imgResize buildImg
      exportAndRemoveImage buildImg destImg
    (LiveInstallerImage name repo imgResize) -> do
      resizeImage imgResize buildImg
      let destImg = Image destFile Raw buildImgFs
          (Image _ _ buildImgFs) = buildImg
          destFile =
            repo </> "machines" </> name </> "disks" </> "raw" </> "0.raw"
          sizeFile =
            repo </> "machines" </> name </> "disks" </> "raw" </> "0.size"
          versFile =
            repo </> "machines" </> name </> "disks" </> "raw" </> "VERSION"
      exportAndRemoveImage buildImg destImg
      cmd
        ( printf
            "echo $(qemu-img info -f raw '%s' | gawk -e '/virtual size/ {print $4}' | tr -d '(') > '%s'"
            destFile
            sizeFile
        )
      buildDate <- getBuildDate
      buildId <- getBuildId
      liftIO (writeFile versFile (buildId ++ "-" ++ buildDate))
    Transient -> return ()

createEmptyImage ::
  IsB9 e =>
  String ->
  FileSystem ->
  ImageType ->
  ImageSize ->
  Image ->
  Eff e ()
createEmptyImage fsLabel fsType imgType imgSize dest@(Image _ imgType' fsType')
  | fsType /= fsType' =
    error
      ( printf
          "Conflicting createEmptyImage parameters. Requested is file system %s but the destination image has %s."
          (show fsType)
          (show fsType')
      )
  | imgType /= imgType' =
    error
      ( printf
          "Conflicting createEmptyImage parameters. Requested is image type %s but the destination image has type %s."
          (show imgType)
          (show imgType')
      )
  | otherwise = do
    let (Image imgFile imgFmt imgFs) = dest
        qemuImgOpts = conversionOptions imgFmt
    dbgL
      ( printf
          "Creating empty raw image '%s' with size %s and options %s"
          imgFile
          (toQemuSizeOptVal imgSize)
          qemuImgOpts
      )
    cmd
      ( printf
          "qemu-img create -f %s %s '%s' '%s'"
          (imageFileExtension imgFmt)
          qemuImgOpts
          imgFile
          (toQemuSizeOptVal imgSize)
      )
    case (imgFmt, imgFs) of
      (Raw, Ext4_64) -> do
        let fsCmd = "mkfs.ext4"
        dbgL (printf "Creating file system %s" (show imgFs))
        cmd (printf "%s -F -L '%s' -O 64bit -q '%s'" fsCmd fsLabel imgFile)
      (Raw, Ext4) -> do
        let fsCmd = "mkfs.ext4"
        dbgL (printf "Creating file system %s" (show imgFs))
        cmd (printf "%s -F -L '%s' -O ^64bit -q '%s'" fsCmd fsLabel imgFile)
      (imageType, fs) ->
        error
          ( printf
              "Cannot create file system %s in image type %s"
              (show fs)
              (show imageType)
          )

createCOWImage :: IsB9 e => Image -> Image -> Eff e ()
createCOWImage (Image backingFile _ _) (Image imgOut imgFmt _) = do
  dbgL (printf "Creating COW image '%s' backed by '%s'" imgOut backingFile)
  cmd
    ( printf
        "qemu-img create -f %s -o backing_file='%s' '%s'"
        (imageFileExtension imgFmt)
        backingFile
        imgOut
    )

resizeExtFS :: (IsB9 e) => ImageSize -> FilePath -> Eff e ()
resizeExtFS newSize img = do
  let sizeOpt = toQemuSizeOptVal newSize
  dbgL (printf "Resizing ext4 filesystem on raw image to %s" sizeOpt)
  cmd (printf "e2fsck -p '%s'" img)
  cmd (printf "resize2fs -f '%s' %s" img sizeOpt)

shrinkToMinimumExtFS :: (IsB9 e) => FilePath -> Eff e ()
shrinkToMinimumExtFS img = do
  dbgL "Shrinking image to minimum size"
  cmd (printf "e2fsck -p '%s'" img)
  cmd (printf "resize2fs -f -M '%s'" img)

-- | Resize an image, including the file system inside the image.
resizeImage :: IsB9 e => ImageResize -> Image -> Eff e ()
resizeImage KeepSize _ = return ()
resizeImage (Resize newSize) (Image img Raw fs)
  | fs == Ext4 || fs == Ext4_64 = resizeExtFS newSize img
resizeImage (ShrinkToMinimumAndIncrease sizeIncrease) (Image img Raw fs)
  | fs == Ext4 || fs == Ext4_64 = do
    shrinkToMinimumExtFS img
    fileSize <- liftIO (getFileSize img)
    let newSize =
          addImageSize
            (bytesToKiloBytes (fromInteger fileSize))
            sizeIncrease
    resizeExtFS newSize img
resizeImage (ResizeImage newSize) (Image img _ _) = do
  let sizeOpt = toQemuSizeOptVal newSize
  dbgL (printf "Resizing image to %s" sizeOpt)
  cmd (printf "qemu-img resize -q '%s' %s" img sizeOpt)
resizeImage ShrinkToMinimum (Image img Raw fs)
  | fs == Ext4 || fs == Ext4_64 = shrinkToMinimumExtFS img
resizeImage _ img =
  error
    ( printf
        "Invalid image type or filesystem, cannot resize image: %s"
        (show img)
    )

-- | Import a disk image from some external source into the build directory
-- if necessary convert the image.
importImage :: IsB9 e => Image -> Image -> Eff e ()
importImage imgIn imgOut@(Image imgOutPath _ _) = do
  alreadyThere <- liftIO (doesFileExist imgOutPath)
  unless alreadyThere (convert False imgIn imgOut)

-- | Export a disk image from the build directory; if necessary convert the image.
exportImage :: IsB9 e => Image -> Image -> Eff e ()
exportImage = convert False

-- | Export a disk image from the build directory; if necessary convert the image.
exportAndRemoveImage :: IsB9 e => Image -> Image -> Eff e ()
exportAndRemoveImage = convert True

-- | Convert an image in the build directory to another format and return the new image.
convertImage :: IsB9 e => Image -> Image -> Eff e ()
convertImage imgIn imgOut@(Image imgOutPath _ _) = do
  alreadyThere <- liftIO (doesFileExist imgOutPath)
  unless alreadyThere (convert True imgIn imgOut)

-- | Convert/Copy/Move images
convert :: IsB9 e => Bool -> Image -> Image -> Eff e ()
convert doMove (Image imgIn fmtIn _) (Image imgOut fmtOut _)
  | imgIn == imgOut = do
    ensureDir imgOut
    dbgL (printf "No need to convert: '%s'" imgIn)
  | doMove && fmtIn == fmtOut = do
    ensureDir imgOut
    dbgL (printf "Moving '%s' to '%s'" imgIn imgOut)
    liftIO $ do
      let exdev e =
            if IO.ioe_errno e == Just ((\(IO.Errno a) -> a) IO.eXDEV)
              then copyFile imgIn imgOut >> removeFile imgIn
              else IO.throw e
      renameFile imgIn imgOut `IO.catch` exdev
  | otherwise = do
    ensureDir imgOut
    dbgL
      ( printf
          "Converting %s to %s: '%s' to '%s'"
          (imageFileExtension fmtIn)
          (imageFileExtension fmtOut)
          imgIn
          imgOut
      )
    cmd
      ( printf
          "qemu-img convert -q -f %s -O %s %s '%s' '%s'"
          (imageFileExtension fmtIn)
          (imageFileExtension fmtOut)
          (conversionOptions fmtOut)
          imgIn
          imgOut
      )
    when doMove $ do
      dbgL (printf "Removing '%s'" imgIn)
      liftIO (removeFile imgIn)

conversionOptions :: ImageType -> String
conversionOptions Vmdk = " -o adapter_type=lsilogic "
conversionOptions QCow2 = " -o compat=1.1,lazy_refcounts=on "
conversionOptions _ = " "

toQemuSizeOptVal :: ImageSize -> String
toQemuSizeOptVal (ImageSize amount u) =
  show amount
    ++ case u of
      GB -> "G"
      MB -> "M"
      KB -> "K"

-- | Publish an sharedImage made from an image and image meta data to the
-- configured repository
shareImage :: IsB9 e => Image -> SharedImageName -> Eff e SharedImage
shareImage buildImg sname@(SharedImageName name) = do
  sharedImage <- createSharedImageInCache buildImg sname
  infoL (printf "SHARED '%s'" name)
  pushToSelectedRepo sharedImage
  return sharedImage

-- TODO Move the functions below to RepositoryIO???

-- | Return a 'SharedImage' with the current build data and build id from the
-- name and disk image.
getSharedImageFromImageInfo ::
  IsB9 e => SharedImageName -> Image -> Eff e SharedImage
getSharedImageFromImageInfo name (Image _ imgType imgFS) = do
  buildId <- getBuildId
  date <- getBuildDate
  return
    ( SharedImage
        name
        (SharedImageDate date)
        (SharedImageBuildId buildId)
        imgType
        imgFS
    )

-- | Convert the disk image and serialize the base image data structure.
-- If the 'maxLocalSharedImageRevisions' configuration is set to @Just n@
-- also delete all but the @n - 1@ newest images from the local cache.
createSharedImageInCache ::
  IsB9 e => Image -> SharedImageName -> Eff e SharedImage
createSharedImageInCache img sname@(SharedImageName name) = do
  dbgL (printf "CREATING SHARED IMAGE: '%s' '%s'" (ppShow img) name)
  sharedImg <- getSharedImageFromImageInfo sname img
  dir <- getSharedImagesCacheDir
  convertImage img (changeImageDirectory dir (sharedImageImage sharedImg))
  prettyPrintToFile (dir </> sharedImageFileName sharedImg) sharedImg
  dbgL (printf "CREATED SHARED IMAGE IN CACHE '%s'" (ppShow sharedImg))
  cleanOldSharedImageRevisionsFromCache sname
  return sharedImg
--
--
--
--
--
--
--    imgDir <- getSharedImagesCacheDir
--    let filesToDelete = (imgDir </>) <$> (infoFiles ++ imgFiles)
--        infoFiles = sharedImageFileName <$> toDelete
--        imgFiles = imageFileName . sharedImageImage <$> toDelete
--    unless (null filesToDelete) $ do
--      traceL
--        ( printf
--            "DELETING %d OBSOLETE REVISIONS OF: %s"
--            (length filesToDelete)
--            (show sn)
--        )
--      mapM_ traceL filesToDelete
--      mapM_ removeIfExists filesToDelete
--  where
--    newestSharedImages :: IsB9 e => Eff e [SharedImage]
--    newestSharedImages =
--      reverse . map snd
--        <$> lookupSharedImages (== Cache) ((sn ==) . sharedImageName)
--    removeIfExists fileName = liftIO $ removeFile fileName `catch` handleExists
--      where
--        handleExists e
--          | isDoesNotExistError e = return ()
--          | otherwise = throwIO e
--
