{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE OverloadedStrings #-}
module PDF.Text (
      CMap
    , CMappers
    , PageContents(..)
    , cMap
    , pageContents
  ) where

import Control.Applicative ((<|>))
import Control.Monad.State (MonadState)
import Data.ByteString.Lazy.Char8 (ByteString)
import Data.Map (Map)
import PDF.Object (Dictionary, blank, name, regular)
import PDF.Output (ObjectId)
import PDF.Parser (Parser, count, runParser, sepBy, string, takeAll)

type CMappers = Map ObjectId CMap
type CMap = Map Int ByteString

data TextOperator = TJ | Tj | Tf | Other

cMap :: ByteString -> CMap
cMap = undefined

data PageContents = PageContents {
    chunks :: [ByteString]
  }

pageContents :: MonadState CMappers m => Dictionary -> ByteString -> m (Either String PageContents)
pageContents font = runParser page

page :: Parser u PageContents
page = PageContents <$> (graphicState <|> text)

graphicState =
  string "q" *> blank *> (command <|> page) `sepBy` blank <* string "Q"
  where
    command =
        count 6 argument *> string "cm"
      <|> name *> blank *> string "gs"
    argument = takeAll regular <* blank