import Control.Monad (when)
import Data.List (foldl', intersperse, intercalate, nub, lookup, isPrefixOf, isInfixOf, find)
import Data.Maybe (fromJust)
import Distribution.PackageDescription hiding (includeDirs)
import Distribution.InstalledPackageInfo(installedPackageId, sourcePackageId, includeDirs)
import Distribution.Simple
import Distribution.Simple.LocalBuildInfo (LocalBuildInfo, localPkgDescr, installedPkgs, withPrograms, buildDir)
import Distribution.Simple.PackageIndex(SearchResult (..), searchByName, allPackages )
import Distribution.Simple.Program (ConfiguredProgram (..), lookupProgram, runProgram, simpleProgram, locationPath)
import Distribution.Simple.Program.Types
import Distribution.Simple.Setup (ConfigFlags, BuildFlags)
import Distribution.System (OS (..), Arch (..), buildOS, buildArch)
import Distribution.Verbosity (normal, verbose)
import System.Cmd (system)
import System.Directory (createDirectoryIfMissing, doesFileExist, getCurrentDirectory, getModificationTime)
import System.Environment (getEnv)
import System.FilePath ((</>), (<.>), replaceExtension, takeFileName, dropFileName, addExtension, takeDirectory)
import System.IO.Unsafe (unsafePerformIO)
import System.Process (readProcess)

-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

main :: IO ()
main = defaultMainWithHooks simpleUserHooks { confHook = myConfHook }

-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

wxcoreDirectory  :: FilePath
wxcoreDirectory  = "src/haskell/Graphics/UI/WXCore"

-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

-- |This slightly dubious function obtains the install path for the wxc package we are using.
-- It works by finding the wxc package's installation info, then finding the include directory 
-- which contains wxc's headers (amongst the wxWidgets include dirs) and then going up a level.
-- It would be nice the path was park of InstalledPackageInfo, but it isn't.
wxcInstallDir :: LocalBuildInfo -> FilePath
wxcInstallDir lbi = 
    case searchByName (installedPkgs lbi) "wxc" of
        Unambiguous wxc_pkgs -> case find (isInfixOf "wxc") . includeDirs . head $ wxc_pkgs of
            Just wxcIncludeDir -> takeDirectory wxcIncludeDir
            Nothing -> error "wxcInstallDir: Couldn't find wxc include dir"
        _ -> error "wxcInstallDir: Couldn't find wxc package in installed packages"

-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

-- Comment out type signature because of a Cabal API change from 1.6 to 1.7
myConfHook (pkg0, pbi) flags = do
    createDirectoryIfMissing True wxcoreDirectory

    lbi <- confHook simpleUserHooks (pkg0, pbi) flags
    let wxcDirectory = wxcInstallDir lbi
        wxcoreIncludeFile = wxcDirectory </> "include/wxc.h"

    putStrLn "Generating class type definitions from .h files"
    system $ "wxdirect -t --wxc " ++ wxcDirectory ++ " -o " ++ wxcoreDirectory ++ " " ++ wxcoreIncludeFile
    putStrLn "Generating class info definitions"
    system $ "wxdirect -i --wxc " ++ wxcDirectory ++ " -o " ++ wxcoreDirectory ++ " " ++ wxcoreIncludeFile
    putStrLn "Generating class method definitions from .h files"
    system $ "wxdirect -c --wxc " ++ wxcDirectory ++ " -o " ++ wxcoreDirectory ++ " " ++ wxcoreIncludeFile

    let lpd       = localPkgDescr lbi
    let lib       = fromJust (library lpd)
    let libbi     = libBuildInfo lib
    let custom_bi = customFieldsBI libbi

    let libbi' = libbi
          { extraLibDirs = extraLibDirs libbi ++ [wxcDirectory]
          , extraLibs    = extraLibs    libbi ++ ["wxc"]
          , ldOptions    = ldOptions    libbi ++ ["-Wl,-rpath," ++ wxcDirectory]  }

    let lib' = lib { libBuildInfo = libbi' }
    let lpd' = lpd { library = Just lib' }

    return $ lbi { localPkgDescr = lpd' }