module Depend
  (dependSingle,  dependSingle',
   dependGallery, dependGallery',
   thumbFile, pageFile)
where

import BuilderQQ
import Info hiding (Text)

import Data.Maybe (fromMaybe)
import Data.Text.Lazy (Text)
import Data.Text.Lazy.Builder (Builder, toLazyText, fromString)
import System.FilePath


dependSingle :: FilePath -- ^ yaml file name (relative to data dir!)
             -> Info
             -> FilePath -- ^ output prefix
             -> FilePath -- ^ build dir
             -> Bool     -- ^ include nsfw?
             -> Text
dependSingle yamlDir info prefix build nsfw =
  toLazyText $ dependSingle' yamlDir info prefix build nsfw

dependSingle' :: FilePath -> Info -> FilePath -> FilePath -> Bool -> Builder
dependSingle' yamlDir info prefix build nsfw =
  let dir    = build </> prefix </> yamlDir
      images = if nsfw then #images info else #sfwImages info
      paths  = map #path images
      index  = dir </> "index.html"
      deps   = thumbFile (thumbnail info) : map pageFile paths ++ paths
      deps'  = unwords $ map (dir </>) deps
  in
  [b|$@index: $@deps'|]

dependGallery :: GalleryInfo
              -> [(FilePath, Info)] -- ^ relative to data dir
              -> FilePath -- ^ build dir
              -> FilePath -- ^ data dir
              -> FilePath -- ^ tmp dir
              -> Text
dependGallery ginfo infos build data_ tmp =
  toLazyText $ dependGallery' ginfo infos build data_ tmp

dependGallery' :: GalleryInfo -> [(FilePath, Info)]
               -> FilePath -> FilePath -> FilePath -> Builder
dependGallery' (GalleryInfo {title, prefix, filters}) infos' build data_ tmp =
  let infos  = filter (matchFilters filters . snd) infos'
      files  = map fst infos
      files' = unwords $ map (data_ </>) files
      page d = build </> prefix </> takeDirectory d </> "index.html"
      pages  = map (page . fst) infos
      pages' = unwords pages
      path   = build </> prefix </> "index.html"
      rules  = makeRules prefix filters build data_ tmp
      inc d  = tmp </> prefix </> takeDirectory d <.> "mk"
      incs   = if null infos then "" else
        "include " <> fromString (unwords $ map inc files)
      index  = build </> "index.html"
  in [b|@0
    $@index: $@path

    $@path: $@pages' $@files'
    	echo "[gallery] "$$@
    	mkdir -p $$(dir $$@)
    	$$(MAKEPAGES) $$(MPFLAGS) gallery -t "$*title" $flags -o "$$@" \
    	  $$(filter $$(DATADIR)/%/$$(INFONAME),$$^)

    $rules

    $incs
  |]
 where
  flags = filtersToFlags filters

makeRules :: FilePath -- ^ prefix
          -> GalleryFilters
          -> FilePath -- ^ build dir
          -> FilePath -- ^ data dir
          -> FilePath -- ^ tmp dir
          -> Builder
makeRules prefix filters build data_ tmp = [b|@0
    $@buildPrefix/%/index.html: $@data_/%/info.yaml
    	echo "[single]  "$$@
    	mkdir -p $$(dir $$@)
    	$$(MAKEPAGES) $$(MPFLAGS) single "$$<" -o "$$@" $flags

    $@tmpPrefix/%.mk: $@data_/%/info.yaml
    	echo "[deps]    "$$@
    	mkdir -p $$(dir $$@)
    	$$(MAKEPAGES) $$(MPFLAGS) depend-single $flags \
    	  -o "$$@" -p "$@prefix" -B "$@build" -D "$@data_" $$<

    $@buildPrefix/%: $@data_/%
    	echo "[copy]    "$$@
    	mkdir -p $$(dir $$@)
    	cp "$$<" "$$@"

    $@buildPrefix/%_small.png: $@data_/%.png
    	echo "[resize]  "$$@
    	mkdir -p $$(dir $$@)
    	convert -resize '$$(SMALL)x$$(SMALL)^' \
    	  -gravity center -crop 1:1+0 "$$<" "$$@"

    $@buildPrefix/%_med.png: $@data_/%.png
    	echo "[resize]  "$$@
    	mkdir -p $$(dir $$@)
    	convert -resize '$$(MED)x$$(MED)>' "$$<" "$$@"
  |]
 where
  buildPrefix = build </> prefix
  tmpPrefix   = tmp </> prefix
  flags       = filtersToFlags filters

filtersToFlags :: GalleryFilters -> Builder
filtersToFlags (GalleryFilters {nsfw}) =
  case nsfw of Just False -> ""; _ -> "-n"

thumbnail :: Info -> FilePath
thumbnail = fromMaybe (error "no thumbnail or sfw images") . #thumb

addSuffix :: String -> FilePath -> FilePath
addSuffix suf path =
  let (pre, ext) = splitExtension path in
  pre ++ suf ++ ext

thumbFile :: FilePath -> FilePath
thumbFile = addSuffix "_small"

pageFile :: FilePath -> FilePath
pageFile f
  | takeExtension f == ".gif" = f
  | otherwise                 = addSuffix "_med" f