{-# LANGUAGE DeriveDataTypeable          #-}
{-# LANGUAGE DeriveGeneric               #-}
{-# LANGUAGE FlexibleContexts            #-}
{-# LANGUAGE FlexibleInstances           #-}
{-# LANGUAGE MultiParamTypeClasses       #-}
{-# LANGUAGE OverloadedLists             #-}
{-# LANGUAGE OverloadedStrings           #-}
{-# LANGUAGE MultiWayIf                  #-}
{-# LANGUAGE PackageImports              #-}
{-# LANGUAGE RecordWildCards             #-}
{-# LANGUAGE ScopedTypeVariables         #-}
{-# LANGUAGE TypeFamilies                #-}
{-# LANGUAGE QuasiQuotes                 #-}
{-# OPTIONS_GHC -fno-warn-name-shadowing #-}

-- |
-- Module      :  Data.SAM.Version1_6.Read.Parser.Header.PG.Base
-- Copyright   :  (c) Matthew Mosior 2023
-- License     :  BSD-style
-- Maintainer  :  mattm.github@gmail.com
-- Portability :  portable
--
-- = WARNING
--
-- This module is considered __internal__.
--
-- The Package Versioning Policy __does not apply__.
--
-- The contents of this module may change __in any way whatsoever__
-- and __without any warning__ between minor versions of this package.
--
-- Authors importing this library are expected to track development
-- closely.
--
-- All credit goes to the author(s)/maintainer(s) of the
-- [containers](https://hackage.haskell.org/package/containers) library
-- for the above warning text.
--
-- = Description
--
-- This library enables the decoding/encoding of SAM, BAM and CRAM file formats.

module Data.SAM.Version1_6.Read.Parser.Header.PG.Base ( -- * SAM_V1_6 parser - header section (Program)
                                                        parse_SAM_V1_6_Program
                                                      ) where

import Data.SAM.Version1_6.Header
import Data.SAM.Version1_6.Read.Error
import Data.SAM.Version1_6.Read.Parser.Header.PG.ID
import Data.SAM.Version1_6.Read.Parser.Header.PG.PN
import Data.SAM.Version1_6.Read.Parser.Header.PG.CL
import Data.SAM.Version1_6.Read.Parser.Header.PG.PP
import Data.SAM.Version1_6.Read.Parser.Header.PG.DS
import Data.SAM.Version1_6.Read.Parser.Header.PG.VN

import Control.Applicative.Permutations           (intercalateEffect,toPermutation,toPermutationWithDefault)
import Data.Attoparsec.ByteString.Char8  as DABC8 (endOfLine)
import Data.Attoparsec.ByteString.Lazy   as DABL
import Text.Regex.PCRE.Heavy

-- | @"SAM_V1_6_Program"@ parser.
--
-- Defines a parser for @PG tag section of the SAM v1.6 file format.
--
-- See the [SAM v1.6](http://samtools.github.io/hts-specs/SAMv1.pdf) specification documentation.
parse_SAM_V1_6_Program :: Parser SAM_V1_6_Program
parse_SAM_V1_6_Program = do
  _         <- do pgheaderp <- DABL.takeTill (== 09)
                  -- Parse @PG tag of the header section.
                  case (pgheaderp =~ [re|[@][P][G]|]) of
                    False -> fail $ show SAM_V1_6_Error_Program_Tag_Incorrect_Format 
                    True  -> -- @PG tag is in the accepted format.
                             return ()
  _         <- word8 09
  -- This parser assumes that the
  -- ID, PN, CL, PP, DS, and VN tags can appear in any order.
  pg <- intercalateEffect (word8 09) $
          SAM_V1_6_Program
            <$> toPermutation parse_SAM_V1_6_Program_ID
            <*> toPermutationWithDefault Nothing
                                         (Just <$> parse_SAM_V1_6_Program_PN)
            <*> toPermutationWithDefault Nothing
                                         (Just <$> parse_SAM_V1_6_Program_CL)
            <*> toPermutationWithDefault Nothing
                                         (Just <$> parse_SAM_V1_6_Program_PP)
            <*> toPermutationWithDefault Nothing
                                         (Just <$> parse_SAM_V1_6_Program_DS)
            <*> toPermutationWithDefault Nothing
                                         (Just <$> parse_SAM_V1_6_Program_VN)
  _ <- endOfLine
  return pg