{-# LANGUAGE BangPatterns         #-}
{-# LANGUAGE DataKinds            #-}
{-# LANGUAGE FlexibleInstances    #-}
{-# LANGUAGE OverloadedStrings    #-}
{-# LANGUAGE ScopedTypeVariables  #-}
{-# LANGUAGE TypeApplications     #-}
{-# LANGUAGE TypeSynonymInstances #-}

module App.Naive
  ( loadSlowCursor
  , loadFastCursor
  ) where

import HaskellWorks.Data.BalancedParens.RangeMin2
import HaskellWorks.Data.BalancedParens.Simple
import HaskellWorks.Data.Bits.BitShown
import HaskellWorks.Data.FromByteString
import HaskellWorks.Data.RankSelect.CsPoppy1
import HaskellWorks.Data.Xml.Succinct.Cursor
import HaskellWorks.Data.Xml.Succinct.Cursor.MMap

import qualified Data.ByteString as BS

-- | Load an XML file into memory and return a raw cursor initialised to the
-- start of the XML document.
loadSlowCursor :: String -> IO SlowCursor
loadSlowCursor path = do
  !bs <- BS.readFile path
  let !cursor = fromByteString bs :: SlowCursor
  return cursor

-- | Load an XML file into memory and return a query-optimised cursor initialised
-- to the start of the XML document.
loadFastCursor :: String -> IO FastCursor
loadFastCursor filename = do
  -- Load the XML file into memory as a raw cursor.
  -- The raw XML data is `text`, and `ib` and `bp` are the indexes.
  -- `ib` and `bp` can be persisted to an index file for later use to avoid
  -- re-parsing the file.
  XmlCursor !text (BitShown !ib) (SimpleBalancedParens !bp) _ <- loadSlowCursor filename
  let !bpCsPoppy = makeCsPoppy bp
  let !rangeMinMax = mkRangeMin2 bpCsPoppy
  let !ibCsPoppy = makeCsPoppy ib
  return $ XmlCursor text ibCsPoppy rangeMinMax 1