{-# LANGUAGE QuasiQuotes, FlexibleContexts #-}

module Formats.Naritachi (
  convertFuriganaTitle,
  convertFuriganaTitleHtml
) where

import Hakyll (Item, Metadata, Compiler, itemIdentifier, getMetadata, lookupString)
import Debug.Trace (traceId)
import Data.Maybe (fromMaybe)
import Text.Regex.PCRE.Heavy

--------------------------------------------------------------------------------
-- FURIGANA CONVERSION

type FuriganaTemplate = String

convertTitle = updateFieldWith "title" "???"

convertFuriganaTitle :: Item a -> Compiler String
convertFuriganaTitle =  convertTitle replaceFuriganaWithKanji

convertFuriganaTitleHtml :: Item a -> Compiler String
convertFuriganaTitleHtml = convertTitle replaceFuriganaWithHtml

updateFieldWith :: String -> String -> (String -> String) -> Item a -> Compiler String
updateFieldWith field defaultPreviousValue f = 
  fmap updateField . getMetadata . itemIdentifier
    where
      updateField :: Metadata -> String
      updateField = traceId . f . fromMaybe defaultPreviousValue . lookupString field

replaceFuriganaWithKanji :: FuriganaTemplate -> String
replaceFuriganaWithKanji = gsub [re|\[(.*?)\]\((.*?)\)|] (\(kanji:kana:_) -> kanji :: String)

replaceFuriganaWithHtml :: FuriganaTemplate -> String
replaceFuriganaWithHtml = between "<ruby>" "</ruby>" . gsub [re|\[(.*?)\]\((.*?)\)|] (\(kanji:kana:_) -> "<rb>" ++ kanji ++"</rb> <rp>(</rp><rt> " ++ kana ++ "</rt><rp>)</rp>" :: String)
  where
    between x y s = x ++ s ++ y
-- toHtml :: FuriganaTemplate -> String
-- toHtml input =
--   "<ruby>"
--   <> subRegex (mkRegex "[(.*?)]\\((.*?)\\)") input "<rb>\1</rb> <rp>(</rp><rt>\2</rt><rp>)</rp>"
--   <> "</ruby>"

-- <!-- <ruby> -->
-- <!--   <rb>す</rb> <rp>(</rp><rt>為</rt><rp>)</rp> -->
-- <!--   <rb>る</rb> -->
-- <!-- </ruby> -->
-- <!-- " -->