#!/usr/bin/env runhaskell
\begin{code}
{-# LANGUAGE CPP #-}

import Control.Monad (unless, mplus)

import Distribution.PackageDescription     (PackageDescription)
import Distribution.Verbosity              (normal)
import Distribution.Simple.Build           (build)
import Distribution.Simple.LocalBuildInfo  (LocalBuildInfo(..))
import Distribution.Simple.PreProcess      (knownSuffixHandlers)
import Distribution.Simple.Program         (programFindLocation, lookupKnownProgram )
import Distribution.Simple.Setup           (defaultBuildFlags)
import Distribution.Simple 
    ( Args, defaultMainWithHooks, UserHooks(..), simpleUserHooks) 

import System.Exit       (ExitCode(..))
import System.FilePath   ( (</>), splitDirectories, isAbsolute )
import System.IO         (openFile, IOMode (..))
import System.Process 
import System.Directory 
    ( getCurrentDirectory, createDirectoryIfMissing
    , setCurrentDirectory, findExecutable, canonicalizePath
    , removeFile, doesDirectoryExist
    )

main :: IO ()
main = defaultMainWithHooks hooks

hooks :: UserHooks
hooks = simpleUserHooks { runTests = testHook } 

findHPC :: LocalBuildInfo -> IO FilePath
findHPC lbi = do
    Just hpcProgram <- return $ lookupKnownProgram "hpc" $ withPrograms lbi
    Just hpc <- programFindLocation hpcProgram normal
    return hpc
 `catch` \_ -> do
    Just hpc <- findExecutable "hpc"
    return hpc

testHook :: Args -> Bool -> PackageDescription -> LocalBuildInfo -> IO ()
testHook args0 _unknown pd lbi = do
    let args = if null args0 then [] else "-t" : args0
    -- dir <- getWorkingDirectory
    let testDir = buildDir lbi </> "test-speculation"
    baseDir <- getCurrentDirectory
    canonicalBuildDir <- canonicalizePath (buildDir lbi)
    t <- doesDirectoryExist testDir
    unless t $ do
        putStrLn "building tests"
        build pd lbi defaultBuildFlags knownSuffixHandlers
        putStrLn "tests built"
    setCurrentDirectory testDir
    do removeFile "test-speculation.tix" 
       putStrLn $ "removed test-speculation.tix" 
     `catch` \_ -> return ()
    exitcode <- system $ unwords $ "test-speculation" : args
    unless (exitcode == ExitSuccess) $ 
        fail "test failed"
    hpc <- findHPC lbi 
    exitcode <- system $ unwords $ hpc 
            : "report" 
            : "test-speculation" 
            : "--srcdir=../../.." 
            : []
    let markupDir base = base </> "doc" </> "html" </> "test-speculation"
    createDirectoryIfMissing True (markupDir canonicalBuildDir)
    exitcode <- system $ unwords $ hpc 
            : "markup" 
            : "test-speculation"
            : "--srcdir=../../.." 
            : ("--destdir=" ++ markupDir canonicalBuildDir) 
            : "--exclude=Main" 
            : []
    unless (exitcode == ExitSuccess) $ 
        fail "hpc report failed"
    putStrLn $ "Code coverage created: " ++ (markupDir (buildDir lbi) </> "hpc_index.html")

\end{code}