
 Copyright ( C ) 2009   <  > 

 This program is free software ; you can redistribute it and/or modify 
 it under the terms of the GNU General Public License as published by 
 the Free Software Foundation ; either version 2 of the License , or 
 ( at your option ) any later version . 

 This program is distributed in the hope that it will be useful , 
 but WITHOUT ANY WARRANTY ; without even the implied warranty of 
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE .   See the 
 GNU General Public License for more details . 

 You should have received a copy of the GNU General Public License 
 along with this program ; if not , write to the Free Software 
 Foundation , Inc. , 59 Temple Place , Suite 330 , Boston , MA   02111 - 1307   USA 

Copyright (C) 2009 John MacFarlane <>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-}

module Yst.Util (stripBlanks, parseAsDate, stripStExt, getStrAttrWithDefault, getStrListWithDefault, fromNString, getDirectoryContentsRecursive, searchPath, errorExit)
where
import Yst.Types
import System.Exit
import System.FilePath
import System.IO (stderr)
  Note : ghc > = 6.12 ( base > = 4.2 ) supports unicode through iconv
  So we use System . IO.UTF8 only if we have an earlier version
#if MIN_VERSION_base(4,2,0)
import System.IO (hPutStrLn)
#else
import System.IO.UTF8 (hPutStrLn)
#endif
import System.Directory
import Data.List (intercalate)
import Data.Char (isSpace)

-- | Strip blank lines from a file.
stripBlanks :: String -> String
stripBlanks = intercalate "\n" . filter (not . all isSpace) . lines

stripStExt :: FilePath -> FilePath
stripStExt f =
  if (takeExtension f == ".st")
     then dropExtension f
     else f

getStrAttrWithDefault :: String -> String -> [(String, Node)] -> String
getStrAttrWithDefault attr def xs =
  case lookup attr xs of
        Just (NString s)   -> s
        Just _             -> error $ attr ++ " must have string value."
        Nothing            -> def

getStrListWithDefault :: String -> String -> [(String, Node)] -> [String]
getStrListWithDefault attr def xs =
  case lookup attr xs of
    Just (NString s) -> [s]
    Just (NList ys) -> map nodeToString ys
    Just _ -> formatError
    Nothing -> [def]
  where nodeToString (NString s) = s
        nodeToString _ = formatError
        formatError = error $ attr ++ " must be a string or list of strings."

fromNString :: Node -> String
fromNString (NString s) = s
fromNString x = error $ "Expected string value, got " ++ show x

getDirectoryContentsRecursive :: FilePath -> IO [FilePath]
getDirectoryContentsRecursive path = do
  isDir <- doesDirectoryExist path
  if isDir
     then do
       contents <- getDirectoryContents path
       let contents' = map (path </>) $ filter (`notElem` ["..","."]) contents
       children <- mapM getDirectoryContentsRecursive contents'
       return (concat children)
     else return [path]

searchPath :: [FilePath] -> FilePath -> IO FilePath
searchPath [] file = return file       -- may or may not exist, but we tried.
searchPath (dir:dirs) file = do
  exists <- doesFileExist curFile
  if exists then return curFile else searchPath dirs file
    where curFile = dir </> file

errorExit :: Int -> String -> IO ()
errorExit lvl msg = hPutStrLn stderr msg >> exitWith (ExitFailure lvl)

 | Strip blank lines from a file.
 may or may not exist, but we tried.

 Copyright ( C ) 2009   <  > 

 This program is free software ; you can redistribute it and/or modify 
 it under the terms of the GNU General Public License as published by 
 the Free Software Foundation ; either version 2 of the License , or 
 ( at your option ) any later version . 

 This program is distributed in the hope that it will be useful , 
 but WITHOUT ANY WARRANTY ; without even the implied warranty of 
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE .   See the 
 GNU General Public License for more details . 

 You should have received a copy of the GNU General Public License 
 along with this program ; if not , write to the Free Software 
 Foundation , Inc. , 59 Temple Place , Suite 330 , Boston , MA   02111 - 1307   USA 

Copyright (C) 2009 John MacFarlane <>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-}

module Yst.Util (stripBlanks, parseAsDate, stripStExt, getStrAttrWithDefault, getStrListWithDefault, fromNString, getDirectoryContentsRecursive, searchPath, errorExit)
where
import Yst.Types
import System.Exit
import System.FilePath
import System.IO (stderr)
  Note : ghc > = 6.12 ( base > = 4.2 ) supports unicode through iconv
  So we use System . IO.UTF8 only if we have an earlier version
#if MIN_VERSION_base(4,2,0)
import System.IO (hPutStrLn)
#else
import System.IO.UTF8 (hPutStrLn)
#endif
import System.Directory
import Data.List (intercalate)
import Data.Char (isSpace)

stripBlanks :: String -> String
stripBlanks = intercalate "\n" . filter (not . all isSpace) . lines

stripStExt :: FilePath -> FilePath
stripStExt f =
  if (takeExtension f == ".st")
     then dropExtension f
     else f

getStrAttrWithDefault :: String -> String -> [(String, Node)] -> String
getStrAttrWithDefault attr def xs =
  case lookup attr xs of
        Just (NString s)   -> s
        Just _             -> error $ attr ++ " must have string value."
        Nothing            -> def

getStrListWithDefault :: String -> String -> [(String, Node)] -> [String]
getStrListWithDefault attr def xs =
  case lookup attr xs of
    Just (NString s) -> [s]
    Just (NList ys) -> map nodeToString ys
    Just _ -> formatError
    Nothing -> [def]
  where nodeToString (NString s) = s
        nodeToString _ = formatError
        formatError = error $ attr ++ " must be a string or list of strings."

fromNString :: Node -> String
fromNString (NString s) = s
fromNString x = error $ "Expected string value, got " ++ show x

getDirectoryContentsRecursive :: FilePath -> IO [FilePath]
getDirectoryContentsRecursive path = do
  isDir <- doesDirectoryExist path
  if isDir
     then do
       contents <- getDirectoryContents path
       let contents' = map (path </>) $ filter (`notElem` ["..","."]) contents
       children <- mapM getDirectoryContentsRecursive contents'
       return (concat children)
     else return [path]

searchPath :: [FilePath] -> FilePath -> IO FilePath
searchPath (dir:dirs) file = do
  exists <- doesFileExist curFile
  if exists then return curFile else searchPath dirs file
    where curFile = dir </> file

errorExit :: Int -> String -> IO ()
errorExit lvl msg = hPutStrLn stderr msg >> exitWith (ExitFailure lvl)
