#!/usr/bin/env stack
{- stack exec
   --verbosity=info
   --package base-prelude
   --package directory
   --package extra
   --package safe
   --package shake
   --package time
   ghc
-}
{-
One of two project scripts files (Makefile, Shake.hs).
This one provides a stronger programming language and more
platform independence than Make. It will build needed packages (above)
on first run and whenever the resolver in stack.yaml changes.
To minimise such startup delays, and reduce sensitivity to git checkout,
compiling is recommended; run the script in interpreted mode to do that.

It requires stack (https://haskell-lang.org/get-started) and
auto-installs the packages above. Also, some rules require:
- runhaskell
- groff
- m4
- makeinfo
- git
- patch

Usage: see below. Also:

$ find hledger-lib hledger | entr ./Shake website    # rebuild web files on changes in these dirs

Shake wishes:
just one shake import
wildcards in phony rules
multiple individually accessible wildcards
not having to write :: Action ExitCode after a non-final cmd
-}

{-# LANGUAGE PackageImports, ScopedTypeVariables #-}

import                Prelude ()
import "base-prelude" BasePrelude
import "directory"    System.Directory as S (getDirectoryContents)
import "extra"        Data.List.Extra
import "safe"         Safe
import "shake"        Development.Shake
import "shake"        Development.Shake.FilePath
import "time"         Data.Time

usage = unlines
  ["Usage:"
  ,"./Shake.hs               # compile this script"
  ,"./Shake                  # show commands"
  ,"./Shake manuals          # generate the txt/man/info manuals"
  ,"./Shake website          # generate the html manuals and website"
--   ,"./Shake manpages         # generate nroff files for man"
--   ,"./Shake txtmanpages      # generate text man pages for embedding"
--   ,"./Shake infomanpages     # generate info files for info"
--   ,"./Shake webmanpages      # generate individual web man pages as markdown"
--   ,"./Shake webmanall        # generate all-in-one web manual as markdown"
  ,"./Shake site/doc/VER/.snapshot   # generate and save a versioned web site snapshot"
  ,"./Shake all              # generate everything"
  ,"./Shake clean            # clean generated files"
  ,"./Shake Clean            # clean harder"
  ,"./Shake --help           # show options, eg --color"
  ]

pandoc = "stack exec -- pandoc" -- pandoc from project's stackage snapshot
pandocSiteFilter = "tools/pandoc-site"
makeinfo = "makeinfo"
-- nroff = "nroff"
groff = "groff"
dropDirectory2 = dropDirectory1 . dropDirectory1

main = do

  shakeArgs
    shakeOptions{
      shakeVerbosity=Loud
      -- ,shakeReport=[".shake.html"]
      } $ do

    want ["help"]

    phony "help" $ liftIO $ putStrLn usage

--     phony "compile" $ need ["Shake"]
--
--     "Shake" %> \out -> do
--       need [out <.> "hs"]
--       unit $ cmd "./Shake.hs"  -- running as stack script installs deps and compiles
--       putLoud "You can now run ./Shake instead of ./Shake.hs"

    phony "all" $ need ["manuals", "website"]

    -- manuals

    let
      manpageNames = [ -- in suggested reading order
         "hledger.1"
        ,"hledger-ui.1"
        ,"hledger-web.1"
        ,"hledger-api.1"
        ,"hledger_journal.5"
        ,"hledger_csv.5"
        ,"hledger_timeclock.5"
        ,"hledger_timedot.5"
        ]

      manualNames = map manpageNameToManualName manpageNames

      -- hledger.1 -> hledger, hledger_journal.5 -> hledger_journal
      manpageNameToManualName = dropNumericSuffix
        where
          dropNumericSuffix s = reverse $
            case reverse s of
              c : '.' : cs | isDigit c -> cs
              cs                       -> cs

      -- hledger -> hledger.1, hledger_journal -> hledger_journal.5
      manualNameToManpageName s
        | '_' `elem` s = s <.> "5"
        | otherwise    = s <.> "1"

      -- manuals m4 source; may include other source files (hledger/hledger.m4.md)
      m4manpages = [manualDir m </> m <.> "m4.md" | m <- manualNames]

      -- manuals rendered to nroff, ready for man (hledger/hledger.1)
      nroffmanpages = [manpageDir m </> m | m <- manpageNames]

      -- manuals rendered to text, ready for embedding (hledger/hledger.txt)
      txtmanpages = [manualDir m </> m <.> "txt" | m <- manualNames]

      -- manuals rendered to info, ready for info (hledger/hledger.info)
      infomanpages = [manualDir m </> m <.> "info" | m <- manualNames]

      -- manuals rendered to markdown, ready for web output by pandoc (site/hledger.md)
      webmanpages = ["site" </> manpageNameToUri m <.> "md" | m <- manpageNames]

      -- versions of documentation (excluding 0.27)
      docversions = [ "1.0" , "1.1" , "1.2" , "1.3" , "1.4" , "1.5" , "1.9" ]

      -- manuals rendered to html by pandoc
      webhtmlpages
        = map (normalise . ("site/_site" </>))
            $ ( [ prefix </> manpageNameToUri mPage <.> "html"
                   | prefix <- "" : [ "doc" </> v | v <- docversions ]
                   , mPage  <- manpageNames
                ]
             ++ [ mPage <.> "html"
                   | mPage <- [ "contributors" , "download" , "ledgertips" , "index" , "intro" , "release-notes" ]
                ]
             ++ [ prefix </> "manual" <.> "html"
                   | prefix <- "" : "doc/0.27" : [ "doc" </> v | v <- docversions ]
                ]
              )

      -- manuals rendered to markdown and combined, ready for web rendering
      webmanall = "site/manual.md"

      -- file extensions which should just be copied directly over to the website
      webcopyfileexts = ["png", "gif", "cur", "js", "css", "eot", "ttf", "woff", "svg"]

      -- hledger.1 -> hledger/doc, hledger_journal.5 -> hledger-lib/doc
      manpageDir m
        | '_' `elem` m = "hledger-lib"
        | otherwise    = dropExtension m

      -- hledger -> hledger, hledger_journal -> hledger-lib
      manualDir m
        | '_' `elem` m = "hledger-lib"
        | otherwise    = m

      -- hledger.1 -> hledger, hledger_journal.5 -> journal
      manpageNameToUri m | "hledger_" `isPrefixOf` m = dropExtension $ drop 8 m
                         | otherwise                 = dropExtension m

      -- hledger -> hledger.1, journal -> hledger_journal.5
      manpageUriToName u | "hledger" `isPrefixOf` u = u <.> "1"
                         | otherwise                = "hledger_" ++ u <.> "5"

    phony "manuals" $ do
      need $
        nroffmanpages
        ++ infomanpages
        ++ txtmanpages

    -- man pages

    -- use m4 and pandoc to process macros, filter content, and convert to nroff suitable for man output
    phony "manpages" $ need nroffmanpages

    nroffmanpages |%> \out -> do -- hledger/hledger.1
      let src = manpageNameToManualName out <.> "m4.md"
          lib = "doc/lib.m4"
          dir = takeDirectory out
          tmpl = "doc/manpage.nroff"
      -- assume all other m4 files in dir are included by this one XXX not true in hledger-lib
      deps <- liftIO $ filter (/= src) . filter (".m4.md" `isSuffixOf`) . map (dir </>) <$> S.getDirectoryContents dir
      need $ src : lib : tmpl : deps
      cmd Shell
        "m4 -P -DMAN -I" dir lib src "|"
        pandoc "-f markdown -s --template" tmpl
        "--lua-filter tools/pandoc-drop-html-blocks.lua"
        "--lua-filter tools/pandoc-drop-html-inlines.lua"
        "--lua-filter tools/pandoc-drop-links.lua"
        "-o" out

    -- render man page nroffs to fixed-width text for embedding in executables, with nroff
    phony "txtmanpages" $ need txtmanpages

    txtmanpages |%> \out -> do  -- hledger/hledger.txt
      let src = manualNameToManpageName $ dropExtension out
      need [src]
      cmd Shell groff "-t -e -mandoc -Tascii" src  "| col -bx >" out -- http://www.tldp.org/HOWTO/Man-Page/q10.html

    -- use m4 and pandoc to process macros, filter content, and convert to info, suitable for info viewing
    phony "infomanpages" $ need infomanpages

    infomanpages |%> \out -> do -- hledger/hledger.info
      let src = out -<.> "m4.md"
          lib = "doc/lib.m4"
          dir = takeDirectory out
      -- assume all other m4 files in dir are included by this one XXX not true in hledger-lib
      deps <- liftIO $ filter (/= src) . filter (".m4.md" `isSuffixOf`) . map (dir </>) <$> S.getDirectoryContents dir
      need $ src : lib : deps
      cmd Shell
        "m4 -P -I" dir lib src "|"
        pandoc "-f markdown"
        "--lua-filter tools/pandoc-drop-html-blocks.lua"
        "--lua-filter tools/pandoc-drop-html-inlines.lua"
        "--lua-filter tools/pandoc-drop-links.lua"
        "-t texinfo |"
        makeinfo "--force --no-split -o" out

    -- web site

    phony "website" $ do
      need $ [ "website-copy" , "website-render" ]

    -- use m4 and pandoc to process macros and filter content, leaving markdown suitable for web output
    phony "webmanpages" $ need webmanpages

    webmanpages |%> \out -> do -- site/hledger.md
      let manpage = manpageUriToName $ dropExtension $ takeFileName out -- hledger
          manual  = manpageNameToManualName manpage
          dir     = manpageDir manpage
          src     = dir </> manual <.> "m4.md"
          lib     = "doc/lib.m4"
          heading = let h = manual
                    in if "hledger_" `isPrefixOf` h
                       then drop 8 h ++ " format"
                       else h
      -- assume all other m4 files in dir are included by this one XXX not true in hledger-lib
      deps <- liftIO $ filter (/= src) . filter (".m4.md" `isSuffixOf`) . map (dir </>) <$> S.getDirectoryContents dir
      need $ src : lib : deps
      liftIO $ writeFile out $ "# " ++ heading ++ "\n\n"
      cmd Shell
        "m4 -P -DMAN -DWEB -I" dir lib src "|"
        pandoc "-f markdown -t markdown-fenced_divs --atx-headers"
        "--lua-filter tools/pandoc-demote-headers.lua"
        ">>" out

    -- adjust and combine man page mds for single-page web output, using pandoc
    phony "webmanall" $ need [ webmanall ]

    webmanall %> \out -> do
      need webmanpages
      liftIO $ writeFile webmanall "* toc\n\n" -- # Big Manual\n\n -- TOC style is better without main heading,
      forM_ webmanpages $ \f -> do -- site/hledger.md, site/journal.md
        cmd Shell ("printf '\\n\\n' >>") webmanall :: Action ExitCode
        cmd Shell "pandoc" f "-t markdown-fenced_divs --atx-headers"
          "--lua-filter tools/pandoc-drop-toc.lua"
          "--lua-filter tools/pandoc-demote-headers.lua"
          ">>" webmanall :: Action ExitCode

    -- adjust and combine recipe mds for single-page web output, using pandoc
    -- build the currently checked out web docs and save as a named snapshot
    "site/doc/*/.snapshot" %> \out -> do
      need [ webmanall ]
      let snapshot = takeDirectory out
      cmd Shell "mkdir -p" snapshot :: Action ExitCode
      forM_ webmanpages $ \f -> do -- site/hledger.md, site/journal.md
        cmd Shell "cp" f (snapshot </> takeFileName f) :: Action ExitCode
      cmd Shell "cp" "site/manual.md" snapshot :: Action ExitCode
      cmd Shell "cp -r site/images" snapshot :: Action ExitCode
      cmd Shell "touch" out -- :: Action ExitCode

    phony "website-copy" $ do
        orig_files <- getDirectoryFiles "site" (map ("//*" <.>) webcopyfileexts)
        need [ "site/_site" </> file
                | file <- "files/README" : orig_files
                , not ("_site//*" ?== file)
             ]

    phony "website-render" $ do
        need webhtmlpages

    pandocSiteFilter %> \out -> do
        let source = out <.> "hs"
        need [source]
        cmd "stack --stack-yaml=stack-ghc8.2.yaml ghc --package pandoc -- -o" out source

    "site/_site/files/README" : [ "site/_site//*" <.> ext | ext <- webcopyfileexts ] |%> \out -> do
        let input = "site" </> dropDirectory2 out
        copyFile' input out

    "site/_site//*.html" %> \out -> do
        let source    = "site" </> dropDirectory2 out -<.> "md"
            pageTitle = takeBaseName out
            template  = "site/site.tmpl"
            siteRoot  = if "site/_site/doc//*" ?== out then "../.." else "."
        need [source, template, pandocSiteFilter]
        cmd Shell pandoc "--from markdown --to html" source
                         "--template"                template
                         ("--metadata=siteRoot:"  ++ siteRoot)
                         ("--metadata=title:"     ++ pageTitle)
                         "--filter"                  pandocSiteFilter
                         "--output"                  out

    -- cleanup

    phony "clean" $ do
      putNormal "Cleaning generated files"
      removeFilesAfter "." webmanpages
      removeFilesAfter "." [webmanall]

    phony "Clean" $ do
      need ["clean"]
      putNormal "Cleaning all site generated files"
      removeFilesAfter "site" ["_*"]
      putNormal "Cleaning object files" -- also forces rebuild of executables
      removeFilesAfter "tools"  ["*.o","*.p_o","*.hi"]
      removeFilesAfter "site" ["*.o","*.p_o","*.hi"]
      putNormal "Cleaning shake build files"
      removeFilesAfter ".shake" ["//*"]