{-# LANGUAGE NoImplicitPrelude #-}

module Panda.Type.Reader where

import Panda.Helper.PreludeEnv
import qualified Data.Map as Map
import Text.Pandoc

import Text.XHtml.Strict
import Data.Default
import Panda.Helper.Html

data Reader = Markdown | RST | HTML | Latex deriving (Show, Eq)

instance Default Reader where
  def = Markdown

readers = 
  [ (Markdown,  ["markdown", "md"])
  , (RST,       ["rst"]  )
  , (HTML,      ["html", "htm"])
  , (Latex,     ["tex", "latex"])
  ]


reader_map  = readers.map gen_lookup.join'.to_h
  where gen_lookup (r, xs) = xs.labeling (const r)

guess_reader ext = reader_map.Map.lookup ext

to_html r = r defaultParserState > writeHtml defaultWriterOptions

-- this list can go on, as long as there is a library that does
-- the convertion. pretty extensible, isn't it.
rr :: Reader -> String -> Html
rr Markdown    = to_html readMarkdown
rr RST         = to_html readRST
rr HTML        = escape_html_unicode > primHtml
rr Latex       = to_html readLaTeX

render_to_html = rr