module AutoPkg.Cabal
	( cabalParse
	, PackageDescription (..)
	)
where

import Distribution.Version
import Distribution.PackageDescription			(FlagName (..), GenericPackageDescription (..), PackageDescription (..))
import Distribution.PackageDescription.Parse		(parsePackageDescription, ParseResult (..))
import Distribution.PackageDescription.Configuration	(finalizePackageDescription)

import qualified Distribution.System			as DS
import qualified Distribution.Compiler			as DC

import System.Info

import AutoPkg.Util

cabalParse :: String  -> IO PackageDescription
cabalParse text
 = do	let	desc	= parsePackageDescription text
	case parsePackageDescription text of
	  ParseOk [] generic -> finalize generic
	  _ -> error ("parsePackageDescription : " ++ (show desc))


finalize :: GenericPackageDescription -> IO PackageDescription
finalize generic
 = do	let	ghc		= versionBranch compilerVersion
	let	compiler	= DC.CompilerId DC.GHC (Version ghc [])
		flags		= [(FlagName "splitBase", True)]
		pkgIndex	= \ _ -> True
		platform	= DS.Platform archId DS.Linux
		result		= finalizePackageDescription flags pkgIndex platform compiler [] generic

	return $ either (error . show) fst result


archId :: DS.Arch
archId
 = case arch of
	-- From Distribution.System
	"i386"		-> DS.I386
	"x86_64"	-> DS.X86_64
	"powerpc"	-> DS.PPC
	"powerpc64"	-> DS.PPC64
	"sparc"		-> DS.Sparc
	"arm"		-> DS.Arm
	"mips"		-> DS.Mips
	"sh"		-> DS.SH
	"ia64"		-> DS.IA64
	"s390"		-> DS.S390
	"alpha"		-> DS.Alpha
	"hppa"		-> DS.Hppa
	"rs6000"	-> DS.Rs6000
	"m68k"		-> DS.M68k
	"vax"		-> DS.Vax
	_		-> errorExit $ "Unknown arch '" ++ arch ++ "'"