gen-album.hs

{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# OPTIONS_GHC -Wall #-}
{-# OPTIONS_GHC -Wcompat #-}
{-# OPTIONS_GHC -Werror #-}
{-# OPTIONS_GHC -Wincomplete-record-updates #-}
{-# OPTIONS_GHC -Wincomplete-uni-patterns #-}
{-# OPTIONS_GHC -Wno-type-defaults #-}
{-# OPTIONS_GHC -Wredundant-constraints #-}

import AlbumTypes
import Codec.Picture (DynamicImage (ImageRGBF), PixelRGBF, convertRGB8, dynamicMap, imageHeight, imageWidth, readImageWithMetadata, savePngImage)
import Codec.Picture.Metadata
import qualified Codec.Picture.Types
import qualified Codec.Picture.Types as M
import Control.Concurrent.Async
import Control.Concurrent.ParallelIO (parallel)
import Control.Monad
import Data.Aeson (decode, encode)
import qualified Data.ByteString.Lazy.Char8 as C
import Data.Either
import Data.List (find, intercalate, sort)
import Data.Maybe
import Data.Time.Clock
import Data.Tuple
import Safe (readEitherSafe)
import ShrinkImage (scaleDownBoxAverage, shrinkImg)
import System.Directory
import System.Environment
import System.Exit
import System.FilePath
import System.IO
import System.IO.Temp (emptyTempFile)
import System.Posix.Files
import Text.Regex

--
-- main & usage
--

main :: IO ()
main = do
  args <- getArgs
  case args of
    [src, dest] -> writeAlbumOrList src dest
    ["shrink", newWidthStr, newHeightStr, oneImg] ->
      case readEitherSafe newWidthStr of
        Right newWidth ->
          case readEitherSafe newHeightStr of
            Right newHeight ->
              shrinkImg newWidth newHeight oneImg
            Left err ->
              putStrLn $ "could not parse new height '" ++ newHeightStr ++ "': " ++ err
        Left err -> putStrLn $ "could not parse new width '" ++ newWidthStr ++ "': " ++ err
    _ -> usage

usage :: IO ()
usage = do
  putStrLn "usage: gen-album <src> <dest>"
  exitWith $ ExitFailure 1

--
-- configuration
--

thumbFilename :: String
thumbFilename = "thumbnail"

sizes :: Int -> [Int]
sizes maxWidth =
  filter (maxWidth >) [1600, 1400, 1200, 1000, 800, 400, 200]

--
-- Album & AlbumList functions
--

writeAlbumOrList :: String -> String -> IO ()
writeAlbumOrList src dest = do
  existingAlbumData <- findExistingAlbumData dest "album.json"
  case existingAlbumData of
    Nothing ->
      putStrLn "album metadata not found; all image metadata will be read from source"
    Just (_, modDate) ->
      putStrLn $ "album metadata dated " ++ show modDate ++ " found; will use it for source images modified earlier than this"
  putStrLn ""
  eAlbumOrList <- genAlbumOrList src src dest existingAlbumData ChooseAutomatically
  case eAlbumOrList of
    Left errs -> do
      putStrLn ""
      putStrLn $ intercalate "\n" errs
      exitWith $ ExitFailure 1
    Right albumOrList -> do
      writeIndexLinks dest dest albumOrList
      C.writeFile (dest </> "album.json") $ encode albumOrList

codeFiles :: [String]
codeFiles = ["index.html", "elbum.js"]

symlinkOverwrite :: FilePath -> FilePath -> IO ()
symlinkOverwrite target linkName = do
  removePathForcibly linkName
  createFileLink target linkName

linkCode :: FilePath -> FilePath -> IO ()
linkCode targetDir linkDir =
  mapM_ (\f -> symlinkOverwrite (targetDir </> f) (linkDir </> f)) codeFiles

writeIndexLinks :: String -> String -> AlbumOrList -> IO ()
writeIndexLinks destRoot dest albumOrList =
  let linkToRealIndex linkName =
        let relLinkName = makeRelative destRoot linkName
            relLinkWithoutTopLevelAlbumName = joinPath $ drop 1 $ splitDirectories relLinkName
            relLinkDepth = length $ splitPath $ takeDirectory relLinkName
            relRealCodePath = joinPath $ replicate relLinkDepth ".."
            finalLinkPath = destRoot </> relLinkWithoutTopLevelAlbumName
         in case relLinkWithoutTopLevelAlbumName == "" of
              True -> pure ()
              False -> do
                createDirectoryIfMissing True finalLinkPath
                linkCode relRealCodePath finalLinkPath
      linkIndexForImage albumTitle i =
        linkToRealIndex $ dest </> albumTitle </> altText i
   in case albumOrList of
        Leaf l -> do
          linkToRealIndex $ dest </> title l
          mapM_ (linkIndexForImage $ title l) $ imageFirst l : imageRest l
        List l -> do
          linkToRealIndex $ dest </> listTitle l
          mapM_ (writeIndexLinks destRoot (dest </> listTitle l)) $ childFirst l : childRest l

findExistingAlbumData :: FilePath -> String -> IO (Maybe (AlbumOrList, UTCTime))
findExistingAlbumData d albumFile = do
  exists <- doesFileExist $ d </> albumFile
  case exists of
    False -> return Nothing
    True -> do
      bytes <- C.readFile $ d </> albumFile
      date <- getModificationTime $ d </> albumFile
      return $ swap . (,) date <$> decode bytes

data ThumbnailSpec
  = ChooseAutomatically
  | RequireExplicit

genAlbumOrList :: FilePath -> FilePath -> FilePath -> Maybe (AlbumOrList, UTCTime) -> ThumbnailSpec -> IO (Either [String] AlbumOrList)
genAlbumOrList srcRoot src dest existingAlbumData thumbspec = do
  files <- filter (`notElem` [".", "..", thumbFilename]) <$> getDirectoryContents src
  let afiles = map (src </>) (sort files)
  epimgs <- procImgsOnly srcRoot src dest existingAlbumData afiles
  case epimgs of
    Left e ->
      return $ Left e
    Right pimgs -> do
      subdirs <- dirsOnly afiles
      let icount = length pimgs
          idirs = length subdirs
      if (icount > 0) && (idirs > 0)
        then return $ Left ["directory " ++ src ++ " contains both images and subdirs, this is not supported"]
        else case pimgs of
          imgFirst : imgRest -> do
            aOrErr <- genAlbum srcRoot src dest imgFirst imgRest
            case aOrErr of
              Left err ->
                return $ Left [err]
              Right a ->
                return $ Right $ Leaf a
          [] ->
            case subdirs of
              dirFirst : dirRest -> do
                en <- genNode srcRoot src dest existingAlbumData thumbspec dirFirst dirRest
                case en of
                  Left err ->
                    return $ Left err
                  Right n ->
                    return $ Right $ List n
              [] ->
                return $ Left ["no images or subdirs in " ++ src]

genNode :: FilePath -> FilePath -> FilePath -> Maybe (AlbumOrList, UTCTime) -> ThumbnailSpec -> FilePath -> [FilePath] -> IO (Either [String] AlbumList)
genNode srcRoot src dest existingAlbumData thumbspec dirFirst dirRest = do
  ecFirst <- genAlbumOrList srcRoot dirFirst dest existingAlbumData RequireExplicit
  case ecFirst of
    Left err ->
      return $ Left err
    Right cFirst -> do
      ecRest <- mapM (\dir -> genAlbumOrList srcRoot dir dest existingAlbumData RequireExplicit) dirRest
      case lefts ecRest of
        [] -> do
          let cRest = rights ecRest
              childImages = getChildImages $ cFirst : cRest
          thumbOrErr <- findThumb srcRoot src dest childImages
          case thumbOrErr of
            Left err ->
              case thumbspec of
                ChooseAutomatically ->
                  case childImages of
                    [] ->
                      return $ Left ["cannot automatically chose a thumbnail when there are no subalbums " ++ titleForDir src]
                    firstChild : _ ->
                      return $
                        Right $
                          AlbumList
                            { listTitle = titleForDir src,
                              listThumbnail = firstChild,
                              childFirst = cFirst,
                              childRest = cRest
                            }
                RequireExplicit ->
                  return $ Left [err]
            Right thumb ->
              return $
                Right $
                  AlbumList
                    { listTitle = titleForDir src,
                      listThumbnail = thumb,
                      childFirst = cFirst,
                      childRest = cRest
                    }
        errs ->
          return $ Left $ concat errs

getChildImages :: [AlbumOrList] -> [Image]
getChildImages =
  concatMap getChildImages1

getChildImages1 :: AlbumOrList -> [Image]
getChildImages1 albumOrList =
  case albumOrList of
    List albumTreeNode ->
      getChildImages $ childFirst albumTreeNode : childRest albumTreeNode
    Leaf album ->
      imageFirst album : imageRest album

genAlbum :: FilePath -> FilePath -> FilePath -> Image -> [Image] -> IO (Either String Album)
genAlbum srcRoot src dest imgFirst imgRest = do
  thumbOrErr <- findThumb srcRoot src dest $ imgFirst : imgRest
  case thumbOrErr of
    Left err ->
      return $ Left err
    Right thumb ->
      return $
        Right $
          Album
            { title = titleForDir src,
              thumbnail = thumb,
              imageFirst = imgFirst,
              imageRest = imgRest
            }

titleForDir :: String -> String
titleForDir dir =
  let dirName = last $ splitDirectories dir
   in subRegex (mkRegex "^[0-9]+_") dirName ""

findThumb :: FilePath -> FilePath -> FilePath -> [Image] -> IO (Either String Image)
findThumb srcRoot src dest images = do
  let thumbLink = src </> thumbFilename
  thumbLinkFileExists <- doesFileExist thumbLink
  if thumbLinkFileExists
    then do
      thumbLinkExists <- pathIsSymbolicLink thumbLink
      if thumbLinkExists
        then do
          thumbPath <- readLink thumbLink
          if isAbsolute $ makeRelative srcRoot thumbPath
            then return $ Left $ src ++ " thumbnail link must point to a path inside " ++ srcRoot ++ ", but does not: " ++ thumbPath
            else do
              let thumbDest = fst $ destForRaw srcRoot dest thumbPath
                  isThumb i = equalFilePath thumbDest (dest </> url (srcSetFirst i))
                  thumb = find isThumb images
              case thumb of
                Nothing ->
                  return $ Left $ src ++ " thumbnail '" ++ thumbLink ++ "' -> '" ++ thumbPath ++ "' (" ++ thumbDest ++ ") does not point to any images in this album: " ++ concatMap (\i -> dest </> url (srcSetFirst i)) images
                Just t ->
                  return $ Right t
        else return $ Left $ thumbLink ++ " is not a symbolic link"
    else return $ Left $ src ++ " does not contain a 'thumbnail' file"

--
-- Single-image functions
--

data FileClassification
  = NotAnImage
  | AlreadyProcessed Image
  | ToProcess (DynamicImage, Metadatas)

toProc :: FileClassification -> Bool
toProc (ToProcess _) = True
toProc _ = False

procImgsOnly :: FilePath -> FilePath -> FilePath -> Maybe (AlbumOrList, UTCTime) -> [FilePath] -> IO (Either [String] [Image])
procImgsOnly _ _ _ _ [] = return $ Right []
procImgsOnly srcRoot src dest existingAlbumData files = do
  let classify f = do
        classification <- classifyFile srcRoot dest existingAlbumData f
        return (f, classification)
  putStrSameLn $ src ++ ": classifying " ++ show (length files) ++ " files ... "
  classifications <- mapConcurrently classify files
  let tpCt = show $ length $ filter toProc $ map snd classifications
  putStr $ tpCt ++ " to process"
  productionResults <- mapConcurrently (produceImage srcRoot dest) classifications
  case lefts productionResults of
    [] ->
      return $ Right $ catMaybes $ rights productionResults
    errs ->
      return $ Left errs

produceImage :: FilePath -> FilePath -> (FilePath, FileClassification) -> IO (Either String (Maybe Image))
produceImage srcRoot dest (f, classification) = do
  case classification of
    NotAnImage ->
      return $ Right Nothing
    AlreadyProcessed img ->
      return $ Right $ Just img
    ToProcess metadata -> do
      eImg <- procImage srcRoot dest (f, metadata)
      case eImg of
        Left err ->
          return $ Left err
        Right img ->
          return $ Right $ Just img

classifyFile :: FilePath -> FilePath -> Maybe (AlbumOrList, UTCTime) -> FilePath -> IO FileClassification
classifyFile srcRoot destDir existingAlbumData file = do
  mImg <- alreadyProcessed srcRoot destDir existingAlbumData file
  case mImg of
    Just img ->
      return $ AlreadyProcessed img
    Nothing -> do
      mMetadata <- imgOnly file
      case mMetadata of
        Just metadata ->
          return $ ToProcess $ snd metadata
        Nothing ->
          return NotAnImage

alreadyProcessed :: FilePath -> FilePath -> Maybe (AlbumOrList, UTCTime) -> FilePath -> IO (Maybe Image)
alreadyProcessed s d existingAlbumData f = do
  let existingImage = do
        -- note: this uses the Maybe instance of Monad
        albumAndModTime <- existingAlbumData
        matchExisting s f $ fst albumAndModTime
      existingImageAndModDate = liftA2 (,) existingImage $ fmap snd existingAlbumData
      destsExist maxWidth = do
        let rawDest = fst $ destForRaw s d f
            allDests = rawDest : map snd (shrinkDests s d f maxWidth)
        existences <- mapM doesFileExist allDests
        return (rawDest, allDests, existences)
  srcModTimeOrNewerImage <- imageNewerThanSrc existingImageAndModDate f
  case srcModTimeOrNewerImage of
    Right newerImage -> do
      (_, _, existences) <- destsExist $ x $ srcSetFirst newerImage
      return $ case and existences of
        True ->
          Just $
            -- work around possible stale image metadata produced
            -- before we were smart enough to avoid creating larger
            -- "shrunken" images
            Image
              { altText = altText newerImage,
                srcSetFirst = srcSetFirst newerImage,
                srcSetRest =
                  filter (\srcSet -> x (srcSetFirst newerImage) > x srcSet) $
                    srcSetRest newerImage
              }
        False -> Nothing
    Left srcModTime -> do
      mi <- imgOnly f
      case mi of
        Nothing ->
          return Nothing
        Just i -> do
          case Codec.Picture.Metadata.lookup Width $ snd $ snd i of
            Nothing -> return Nothing
            Just width -> do
              (rawDest, allDests, existences) <- destsExist $ fromIntegral width
              case and existences of
                True -> do
                  -- the destination images all exist
                  -- the source image exists, but is newer than the metadata we have from album.json
                  -- the source image also loads cleanly and we have its intrinsic metadata
                  -- however, it's only safe to use that instrinsic metadata if the destination images
                  -- are all *newer* than the source image
                  destModTimes <- mapM getModificationTime allDests
                  case maximum destModTimes > srcModTime of
                    True -> createImageWithMetadataSize s d f rawDest i
                    False -> return Nothing
                False -> return Nothing

shrinkDests :: FilePath -> FilePath -> FilePath -> Int -> [(Int, FilePath)]
shrinkDests s d f maxWidth =
  map
    ( \size ->
        ( size,
          fst $ destForShrink size s d f
        )
    )
    $ sizes maxWidth

matchExisting :: FilePath -> FilePath -> AlbumOrList -> Maybe Image
matchExisting s f albumOrList = do
  let relNames = splitDirectories $ makeRelative s f
   in findImage relNames albumOrList

findImage :: [String] -> AlbumOrList -> Maybe Image
findImage [] _ = Nothing
findImage (name : names) albumOrList =
  let getTitle aol =
        case aol of
          List list -> listTitle list
          Leaf album -> title album
      matchesName = (==) (titleForDir name) . getTitle
   in case albumOrList of
        List list ->
          case filter matchesName $ childFirst list : childRest list of
            [] -> Nothing
            _ : _ : _ -> Nothing
            [child] -> findImage names child
        Leaf album ->
          case filter ((==) (takeBaseName name) . altText) $ imageFirst album : imageRest album of
            [] -> Nothing
            _ : _ : _ -> Nothing
            [child] -> Just child

imageNewerThanSrc :: Maybe (Image, UTCTime) -> FilePath -> IO (Either UTCTime Image)
imageNewerThanSrc mImageModTime src = do
  srcModTime <- getModificationTime src
  case mImageModTime of
    Nothing ->
      return $ Left srcModTime
    Just (image, modTime) ->
      case modTime >= srcModTime of
        True ->
          -- putStrLn $ "found image in album metadata @ " ++ (show modTime) ++ " newer than src " ++ src ++ " @ " ++ (show srcModTime) ++ ": " ++ (show image)
          return $ Right image
        False ->
          -- putStrLn $ "found image in album metadata @ " ++ (show modTime) ++ " older than src " ++ src ++ " @ " ++ (show srcModTime) ++ ": " ++ (show image)
          return $ Left srcModTime

createImageWithMetadataSize :: FilePath -> FilePath -> FilePath -> FilePath -> (FilePath, (DynamicImage, Metadatas)) -> IO (Maybe Image)
createImageWithMetadataSize s d f rawDest i = do
  let mw = Codec.Picture.Metadata.lookup Width $ snd $ snd i
      mh = Codec.Picture.Metadata.lookup Height $ snd $ snd i
      wh = maybeTuple (mw, mh)
  case wh of
    Just (ww, hw) -> do
      let t = takeBaseName f
          w = fromIntegral ww
          h = fromIntegral hw
          srcSetFst =
            ImgSrc
              { url = makeRelative d rawDest,
                x = w,
                y = h
              }
          sdToImgSrc sd =
            let (xsm, ysm) = shrink (fst sd) w h
             in ImgSrc
                  { url = makeRelative d $ snd sd,
                    x = xsm,
                    y = ysm
                  }
          srcSetRst = map sdToImgSrc $ shrinkDests s d f w
      return $
        Just $
          Image
            { altText = t,
              srcSetFirst = srcSetFst,
              srcSetRest = srcSetRst
            }
    Nothing ->
      return Nothing

imgOnly :: FilePath -> IO (Maybe (FilePath, (DynamicImage, Metadatas)))
imgOnly f = do
  loadResult <- readImageWithMetadata f
  case loadResult of
    Left _ -> return Nothing
    Right img ->
      do
        -- putStrSameLn $ "loaded " ++ show f
        return $ Just (f, img)

procImage :: FilePath -> FilePath -> (FilePath, (DynamicImage, Metadatas)) -> IO (Either String Image)
procImage s d (f, i) = do
  let w = dynamicMap imageWidth $ fst i
      h = dynamicMap imageHeight $ fst i
      mw = Codec.Picture.Metadata.lookup Width $ snd i
      mh = Codec.Picture.Metadata.lookup Height $ snd i
      mwh = maybeTuple (mw, mh)
      t = takeBaseName f
  case mwh of
    Nothing ->
      return $ Left $ "image " ++ f ++ " has no size metadata, album regen will silently drop it"
    Just (ww, hh) ->
      if fromIntegral ww == w && fromIntegral hh == h
        then do
          (srcSetFst, srcSetRst) <- procSrcSet s d f (fst i) w h
          return $
            Right $
              Image
                { altText = t,
                  srcSetFirst = srcSetFst,
                  srcSetRest = srcSetRst
                }
        else return $ Left $ "image " ++ f ++ " has intrinsic w*h of " ++ show w ++ "*" ++ show h ++ " but metadata w*h of " ++ show ww ++ "*" ++ show hh ++ "; to repair, load in The Gimp, then choose file -> overwrite"

procSrcSet :: FilePath -> FilePath -> FilePath -> DynamicImage -> Int -> Int -> IO (ImgSrc, [ImgSrc])
procSrcSet s d f i w h = do
  rawImg <- copyRawImgSrc s d f w h
  {- note: we combine shrinking the image and writing it out to disk as a single
  parallelizable operation.  if instead we parallelize all the shrinking
  operations first, then parallelize all the writing, we keep all the shrunken
  images in memory at once -}
  shrunken <- parallel $ map (shrinkAndWrite s d f i w h) (sizes w)
  return (rawImg, shrunken)

shrinkAndWrite :: FilePath -> FilePath -> FilePath -> DynamicImage -> Int -> Int -> Int -> IO ImgSrc
shrinkAndWrite s d f i w h maxwidth = do
  let (rgbfImgSmall, fsmpath, imgSrc) = shrinkImgSrc s d f i w h maxwidth
  writeShrunkenImgSrc (rgbfImgSmall, fsmpath)
  return imgSrc

writeShrunkenImgSrc :: (Codec.Picture.Types.Image PixelRGBF, FilePath) -> IO ()
writeShrunkenImgSrc (ism, fsmpath) = do
  createDirectoryIfMissing True $ takeDirectory fsmpath
  hFlush stdout
  withTempFileCopiedTo fsmpath $ \tmpFile ->
    savePngImage tmpFile $ ImageRGBF ism

shrinkImgSrc :: FilePath -> FilePath -> FilePath -> DynamicImage -> Int -> Int -> Int -> (Codec.Picture.Types.Image PixelRGBF, FilePath, ImgSrc)
shrinkImgSrc s d f i w h maxwidth =
  let (xsm, ysm) = shrink maxwidth w h
      fsmpath = fst $ destForShrink maxwidth s d f
      rgbfImg = M.promoteImage $ convertRGB8 i
      rgbfImgSmall = scaleDownBoxAverage xsm ysm rgbfImg
   in ( rgbfImgSmall,
        fsmpath,
        ImgSrc
          { url = makeRelative d fsmpath,
            x = xsm,
            y = ysm
          }
      )

copyRawImgSrc :: FilePath -> FilePath -> FilePath -> Int -> Int -> IO ImgSrc
copyRawImgSrc s d fpath w h = do
  let (dest, _) = destForRaw s d fpath
  createDirectoryIfMissing True $ takeDirectory dest
  withTempFileCopiedTo dest $ copyFile fpath
  -- putStrSameLn $ "copied " ++ f
  return
    ImgSrc
      { url = makeRelative d dest,
        x = w,
        y = h
      }

destForRaw :: FilePath -> FilePath -> FilePath -> (FilePath, FilePath)
destForRaw =
  destFor takeFileName

destForShrink :: Int -> FilePath -> FilePath -> FilePath -> (FilePath, FilePath)
destForShrink maxwidth =
  destFor (\f -> takeFileName (dropExtension f) ++ "." ++ show maxwidth ++ ".png")

destFor :: (FilePath -> FilePath) -> FilePath -> FilePath -> FilePath -> (FilePath, FilePath)
destFor fNameMaker src dest fileInSrc =
  let srel = takeDirectory $ makeRelative src fileInSrc
      fName = fNameMaker fileInSrc
   in (dest </> srel </> fName, fName)

shrink :: Int -> Int -> Int -> (Int, Int)
shrink maxwidth w h =
  let factor = fromIntegral maxwidth / fromIntegral w
      scale dim = floor (fromIntegral dim * factor)
   in (scale w, scale h)

--
-- file/directory utilities
--

dirsOnly :: [FilePath] -> IO [FilePath]
dirsOnly = filterM doesDirectoryExist

readLink :: FilePath -> IO FilePath
readLink f = do
  isLink <- pathIsSymbolicLink f
  if isLink
    then do
      target <- getSymbolicLinkTarget f
      if isAbsolute target
        then readLink target
        else do
          let ftgt = takeDirectory f </> target
          readLink ftgt
    else return f

withTempFileCopiedTo :: FilePath -> (FilePath -> IO ()) -> IO ()
withTempFileCopiedTo dest operation = do
  tmpFile <- emptyTempFile (takeDirectory dest) "elbum.tmp"
  operation tmpFile
  renameFile tmpFile dest
  setFileMode dest $ foldl unionFileModes ownerReadMode [groupReadMode, otherReadMode]

--
-- I/O utilities
--

putStrSameLn :: String -> IO ()
putStrSameLn s = do
  putStr "\r                                                                                                                                                          "
  putStr "\r"
  putStr s
  hFlush stdout

--
-- basic utilities
--

maybeTuple :: (Maybe a, Maybe b) -> Maybe (a, b)
maybeTuple (ma, mb) =
  case ma of
    Just a ->
      case mb of
        Just b ->
          Just (a, b)
        Nothing ->
          Nothing
    Nothing ->
      Nothing