{- |
Module      :  ELynx.Import.MarkovProcess.SiteprofilesPhylobayes
Description :  Import site profiles in Phylobayes format
Copyright   :  (c) Dominik Schrempf 2020
License     :  GPL-3.0-or-later

Maintainer  :  dominik.schrempf@gmail.com
Stability   :  unstable
Portability :  portable

Creation date: Tue Jan 29 12:12:55 2019.

For now I just try to go with a huge empirical distribution mixture model. Let's
see if performance is good enough.

There are subtle differences between
`ELynx.Import.MarkovProcess.EDMModelPhylobayes` and this module, which collects
one stationary distribution for each site.

-}

module ELynx.Import.MarkovProcess.SiteprofilesPhylobayes
  ( siteprofiles
  )
where

import           Control.Monad
import           Data.List                      ( nub )
import qualified Data.Vector.Storable          as V
import           Text.Megaparsec
import           Text.Megaparsec.Byte
import           Text.Megaparsec.Byte.Lexer

import           ELynx.Tools

import           ELynx.Import.MarkovProcess.EDMModelPhylobayes
                                                ( Parser
                                                , EDMComponent
                                                )

-- | Parse stationary distributions from Phylobayes format.
siteprofiles :: Parser [EDMComponent]
siteprofiles = do
  _  <- headerLines
  cs <- many dataLine
  _  <- many newline *> eof <?> "phylobayes siteprofiles"
  let ls  = map length cs
      nLs = length $ nub ls
  when (nLs /= 1)
       (error "The site profiles have a different number of entries.")
  return cs

horizontalSpace :: Parser ()
horizontalSpace = skipMany $ char (c2w ' ') <|> tab

line :: Parser ()
line = do
  _ <- many $ noneOf [c2w '\n']
  pure ()

-- For now, just ignore the header.
headerLines :: Parser ()
headerLines = do
  _ <- line
  _ <- many newline <?> "headerLine"
  pure ()

dataLine :: Parser EDMComponent
dataLine = do
  -- Ignore site number.
  _    <- decimal :: Parser Integer
  _    <- horizontalSpace
  -- Also ignore additional white space on line.
  vals <- float `sepEndBy1` horizontalSpace
  _    <- many newline <?> "dataLine"
  -- Set the weight to 1.0 for all sites.
  return (1.0, V.fromList vals)