{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE RankNTypes #-}

-----------------------------------------------------------------------------
-- |
-- Module      :  Distribution.Simple.Program.Hpc
-- Copyright   :  Thomas Tuegel 2011
--
-- Maintainer  :  cabal-devel@haskell.org
-- Portability :  portable
--
-- This module provides an library interface to the @hpc@ program.

module Distribution.Simple.Program.Hpc
    ( markup
    , union
    ) where

import Prelude ()
import Distribution.Compat.Prelude

import System.Directory (makeRelativeToCurrentDirectory)

import Distribution.ModuleName
import Distribution.Simple.Program.Run
import Distribution.Simple.Program.Types
import Distribution.Pretty
import Distribution.Simple.Utils
import Distribution.Verbosity
import Distribution.Version

-- | Invoke hpc with the given parameters.
--
-- Prior to HPC version 0.7 (packaged with GHC 7.8), hpc did not handle
-- multiple .mix paths correctly, so we print a warning, and only pass it the
-- first path in the list. This means that e.g. test suites that import their
-- library as a dependency can still work, but those that include the library
-- modules directly (in other-modules) don't.
markup :: ConfiguredProgram
       -> Version
       -> Verbosity
       -> FilePath            -- ^ Path to .tix file
       -> [FilePath]          -- ^ Paths to .mix file directories
       -> FilePath            -- ^ Path where html output should be located
       -> [ModuleName]        -- ^ List of modules to exclude from report
       -> IO ()
markup hpc hpcVer verbosity tixFile hpcDirs destDir excluded = do
    hpcDirs' <- if withinRange hpcVer (orLaterVersion version07)
        then return hpcDirs
        else do
            warn verbosity $ "Your version of HPC (" ++ prettyShow hpcVer
                ++ ") does not properly handle multiple search paths. "
                ++ "Coverage report generation may fail unexpectedly. These "
                ++ "issues are addressed in version 0.7 or later (GHC 7.8 or "
                ++ "later)."
                ++ if null droppedDirs
                    then ""
                    else " The following search paths have been abandoned: "
                        ++ show droppedDirs
            return passedDirs

    -- Prior to GHC 8.0, hpc assumes all .mix paths are relative.
    hpcDirs'' <- traverse makeRelativeToCurrentDirectory hpcDirs'

    runProgramInvocation verbosity
      (markupInvocation hpc tixFile hpcDirs'' destDir excluded)
  where
    version07 = mkVersion [0, 7]
    (passedDirs, droppedDirs) = splitAt 1 hpcDirs

markupInvocation :: ConfiguredProgram
                 -> FilePath            -- ^ Path to .tix file
                 -> [FilePath]          -- ^ Paths to .mix file directories
                 -> FilePath            -- ^ Path where html output should be
                                        -- located
                 -> [ModuleName]        -- ^ List of modules to exclude from
                                        -- report
                 -> ProgramInvocation
markupInvocation hpc tixFile hpcDirs destDir excluded =
    let args = [ "markup", tixFile
               , "--destdir=" ++ destDir
               ]
            ++ map ("--hpcdir=" ++) hpcDirs
            ++ ["--exclude=" ++ prettyShow moduleName
               | moduleName <- excluded ]
    in programInvocation hpc args

union :: ConfiguredProgram
      -> Verbosity
      -> [FilePath]         -- ^ Paths to .tix files
      -> FilePath           -- ^ Path to resultant .tix file
      -> [ModuleName]       -- ^ List of modules to exclude from union
      -> IO ()
union hpc verbosity tixFiles outFile excluded =
    runProgramInvocation verbosity
      (unionInvocation hpc tixFiles outFile excluded)

unionInvocation :: ConfiguredProgram
                -> [FilePath]       -- ^ Paths to .tix files
                -> FilePath         -- ^ Path to resultant .tix file
                -> [ModuleName]     -- ^ List of modules to exclude from union
                -> ProgramInvocation
unionInvocation hpc tixFiles outFile excluded =
    programInvocation hpc $ concat
        [ ["sum", "--union"]
        , tixFiles
        , ["--output=" ++ outFile]
        , ["--exclude=" ++ prettyShow moduleName
          | moduleName <- excluded ]
        ]
