----------------------------------------------------------------------
--
-- Module      :   create an index for a directory
---- | create an index for a directory
--  in two steps: 
--  IndexCollect collect all the date
--  with call to completeIndex
--  and
--  indexmake: convert collected data for printing (convertIndexEntries)
--  .
--  the data is stored in a file separately and managed by Shake
--  operates on metapage (or less? )
----------------------------------------------------------------------
{-# LANGUAGE OverloadedStrings #-}
-- {-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# OPTIONS_GHC -Wall #-}

module Lib.IndexCollect where

-- import Uniform.Json  
import Uniform.Pandoc ( extMD )
import Uniform.Latex
import Foundational.Filetypes4sites ( Docrep(Docrep) )
import Foundational.MetaPage
 
import Foundational.CmdLineFlags ( PubFlags )

import UniformBase

import Wave.Md2doc
    ( includeBakeTest3docrep, readMarkdownFile2docrep ) 
-- import ShakeBake.Bake (readMarkdownFile2docrep)
import Foundational.SettingsPage  
import Data.List (sortOn)



completeIndex :: NoticeLevel -> PubFlags -> Settings -> Path Abs Dir -> Maybe Text ->   IndexEntry -> ErrIO IndexEntry
{- ^ the top call to form the index data into the MetaPage
later only the format for output must be fixed
-}
completeIndex debug pubf sett4 doughP indexSortField ix1 = do
    when (inform debug) $ putIOwords ["completeIndex", "start", showPretty ix1]

    let fn = doughP </> (link ix1) :: Path Abs File
    -- changed to search in dough (but no extension yet)

    when (inform debug) $   -- to have indication where error is if pandoc error 
        putIOwords
            [ "completeIndex"
            , "fn"
            , showT fn
            ]
    -- unless (isIndexPage fn) $ errorT ["completeIndex should only be called for indexPage True"]

    (dirs, files) <- getDirContent2dirs_files debug pubf sett4 doughP  fn
    let
        dirs1 = sortField dirs 
        files1 = sortField files
    -- sort entries 

    when (inform debug) $ putIOwords ["completeIndex", "\n dirs", showT dirs, "\n files", showT files]
    let ix2 = ix1{dirEntries = dirs1, fileEntries = files1}
    when (inform debug) $ putIOwords ["completeIndex", "x2", showT ix2]
    return ix2

  where 
    sortField = case (indexSortField) of 
        Just "filename" -> sortOn link
        Just "date"      -> sortOn date 
        Just "reversedate" -> reverse . sortOn  date
        _ -> sortOn link   -- what is best default? id?


{- | get the contents of a directory, separated into dirs and files
 the directory is given by the index file
 which files to check: index.md (in dough) or index.docrep (in baked)
 currently checks index.docrep in dough (which are not existing)
 indexfile itself is removed and files which are not markdown
-}
getDirContent2dirs_files :: NoticeLevel -> PubFlags -> Settings -> Path Abs Dir ->  Path Abs File -> ErrIO ([IndexEntry], [IndexEntry])
getDirContent2dirs_files debug pubf sett4 doughP   indexpageFn = do
    when (inform debug) $ putIOwords ["getDirContent2dirs_files for", showPretty indexpageFn]
    let pageFn = makeAbsDir $ getParentDir indexpageFn :: Path Abs Dir
    -- get the dir in which the index file is embedded
    when (inform debug) $ putIOwords ["getDirContent2dirs_files pageFn", showPretty pageFn]

    dirs1 :: [Path Abs Dir] <- getDirectoryDirs' pageFn
    let dirs2 =  filter (not . isInfixOf' (doNotBake (siteLayout sett4)). s2t . getNakedDir) dirs1
    let dirs3 = filter ( not . (isPrefixOf' resourcesName) .  getNakedDir) dirs2
    let dirs4 = filter ( not . (isPrefixOf'  templatesName) . getNakedDir) dirs3
    let dirs5 = filter ( not . (isPrefixOf' "."
         ) .   getNakedDir) dirs4
    -- TODO may need extension (change to list of excluded)
    -- build from constants in foundation

    when (inform debug) $ putIOwords ["\ngetDirContent2dirs_files dirs4", showPretty dirs4]

    files1 :: [Path Abs File] <- getDirContentFiles pageFn

    when (inform debug) $ putIOwords ["getDirContent2dirs_files files1", showPretty files1]
 
    let files2 =
            filter (indexpageFn /=) -- should not exclude all index pages but has only this one in this dir?
                . filter (hasExtension extMD)  
                . filter (not . isInfixOf' (doNotBake (siteLayout sett4)) . s2t. toFilePath)
                $ files1
    when (inform debug) $ putIOwords ["getDirContent2dirs files2", showPretty files2]
    -- let hpname = blogAuthorToSuppress sett4
    ixfiles <- mapM (getFile2index debug pubf sett4 ) files2

    when (inform debug) $ putIOwords ["getDirContent2dirs ixfiles", showPretty ixfiles]

    let subindexDirs = map (\d -> d </> makeRelFile "index.md") dirs5
    
    when (inform debug) $  putIOwords ["getDirContent2dirs subindexDirs", showPretty subindexDirs]
    ixdirs <- mapM (getFile2index  debug pubf sett4 ) subindexDirs

    when (inform debug) $ putIOwords ["getDirContent2dirs xfiles", showPretty ixfiles, "\n ixdirs", showPretty ixdirs]

    return (catMaybes ixdirs, catMaybes ixfiles)



getFile2index :: NoticeLevel -> PubFlags -> Settings  -> Path Abs File -> ErrIO (Maybe IndexEntry)
-- get a file and its index
-- collect data for indexentry (but not recursively, only this file)
-- the directories are represented by their index files
-- produce separately to preserve the two groups
-- the excluded (do not bake) files are filtered out before
getFile2index debug pubf sett4   fnin =
    do
        when (inform debug) $ putIOwords ["getFile2index fnin", showPretty fnin
                ,"\ndebug", showT debug]

        -- mdfile <- read8 fnin markdownFileType 
        -- pd <- readMarkdown2 mdfile
        -- -- could perhaps "need" all ix as files?

        -- let (Docrep y1 _) = pandoc2docrep doughP fnin pd
        (Docrep y1 _) <- readMarkdownFile2docrep debug sett4  fnin 
        -- needs the indexentry initialized
        -- does include the DNB files, bombs with ff ligature
        let incl = includeBakeTest3docrep pubf y1
        
        if incl then do
            let ix1 :: IndexEntry =  dyIndexEntry y1
            when (inform debug) $ putIOwords ["getFile2index ix1", showPretty ix1]
            return . Just $ ix1
                        
        else return Nothing