-----------------------------------------------------------------------------
-- |
-- Module      :  Distribution.Client.Haddock
-- Copyright   :  (c) Andrea Vezzosi 2009
-- License     :  BSD-like
--
-- Maintainer  :  cabal-devel@haskell.org
-- Portability :  portable
--
-- Interfacing with Haddock
--
-----------------------------------------------------------------------------
module Distribution.Client.Haddock
    (
     regenerateHaddockIndex
    )
    where

import Data.List (maximumBy)
import Data.Foldable (forM_)
import System.Directory (createDirectoryIfMissing, renameFile)
import System.FilePath ((</>), splitFileName)
import Distribution.Package
         ( packageVersion )
import Distribution.Simple.Haddock (haddockPackagePaths)
import Distribution.Simple.Program (haddockProgram, ProgramDb
                                   , runProgram, requireProgramVersion)
import Distribution.Version (mkVersion, orLaterVersion)
import Distribution.Verbosity (Verbosity)
import Distribution.Simple.PackageIndex
         ( InstalledPackageIndex, allPackagesByName )
import Distribution.Simple.Utils
         ( comparing, debug, installDirectoryContents, withTempDirectory )
import Distribution.InstalledPackageInfo as InstalledPackageInfo
         ( InstalledPackageInfo(exposed) )

regenerateHaddockIndex :: Verbosity
                       -> InstalledPackageIndex -> ProgramDb
                       -> FilePath
                       -> IO ()
regenerateHaddockIndex verbosity pkgs progdb index = do
      (paths, warns) <- haddockPackagePaths pkgs' Nothing
      let paths' = [ (interface, html) | (interface, Just html) <- paths]
      forM_ warns (debug verbosity)

      (confHaddock, _, _) <-
          requireProgramVersion verbosity haddockProgram
                                    (orLaterVersion (mkVersion [0,6])) progdb

      createDirectoryIfMissing True destDir

      withTempDirectory verbosity destDir "tmphaddock" $ \tempDir -> do

        let flags = [ "--gen-contents"
                    , "--gen-index"
                    , "--odir=" ++ tempDir
                    , "--title=Haskell modules on this system" ]
                 ++ [ "--read-interface=" ++ html ++ "," ++ interface
                    | (interface, html) <- paths' ]
        runProgram verbosity confHaddock flags
        renameFile (tempDir </> "index.html") (tempDir </> destFile)
        installDirectoryContents verbosity tempDir destDir

  where
    (destDir,destFile) = splitFileName index
    pkgs' = [ maximumBy (comparing packageVersion) pkgvers'
            | (_pname, pkgvers) <- allPackagesByName pkgs
            , let pkgvers' = filter exposed pkgvers
            , not (null pkgvers') ]