, OverloadedStrings
  , QuasiQuotes
  , UnicodeSyntax
-- | Handling static files on the filesystem.
module Network.HTTP.Lucu.StaticFile
    ( staticFile
    , staticDir
import Control.Monad
import Control.Monad.Unicode
import Control.Monad.Trans
import Data.ByteString (ByteString)
import qualified Data.ByteString.Lazy.Char8 as LBS
import Data.Convertible.Base
import Data.Convertible.Instances.Text ()
import Data.Monoid.Unicode
import Data.String
import qualified Data.Text.Encoding as T
import Network.HTTP.Lucu.Abortion
import Network.HTTP.Lucu.Config
import Network.HTTP.Lucu.MIMEType
import Network.HTTP.Lucu.MIMEType.Guess
import Network.HTTP.Lucu.Resource
import Network.HTTP.Lucu.Resource.Internal
import Network.HTTP.Lucu.Response.StatusCode
import Network.HTTP.Lucu.Utils
import Prelude.Unicode
import System.Directory
import System.FilePath

-- | @'staticFile' fpath@ is a 'Resource' which serves the file at
-- @fpath@ on the filesystem.
staticFile  FilePath  Resource
staticFile path
    = () {
        resGet  = Just $ handleStaticFile True  path
      , resHead = Just $ handleStaticFile False path

octetStream  MIMEType
octetStream = [mimeType| application/octet-stream |]

handleStaticFile  Bool  FilePath  Rsrc ()
handleStaticFile sendContent path
    = do isDir  liftIO $ doesDirectoryExist path
         when isDir
             $ abort
             $ mkAbortion Forbidden [] Nothing

         isFile  liftIO $ doesFileExist path
         unless isFile

         perms  liftIO $ getPermissions path
         unless (readable perms)
             $ abort
             $ mkAbortion Forbidden [] Nothing

         lastMod  liftIO $ getLastModified path
         foundTimeStamp lastMod

         conf  getConfig
         case guessTypeByFileName (cnfExtToMIMEType conf) path of
           Nothing    setContentType octetStream
           Just mime  setContentType mime

         when sendContent
             $ liftIO (LBS.readFile path) = putChunks

-- | @'staticDir' dir@ is a 'Resource' which maps all files in @dir@
-- and its subdirectories on the filesystem to the resource tree. Thus
-- having 'Network.HTTP.Lucu.nonGreedy' 'staticDir' in a tree makes no
-- sense.
-- Note that 'staticDir' currently doesn't have a directory-listing
-- capability. Requesting the content of a directory will end up being
-- replied with /403 Forbidden/.
staticDir  FilePath  Resource
staticDir path
    = () {
        resGet  = Just $ handleStaticDir True  path
      , resHead = Just $ handleStaticDir False path

-- TODO: implement directory listing.
handleStaticDir  Bool  FilePath  Rsrc ()
handleStaticDir sendContent basePath
    = do extraPath  getPathInfo
         securityCheck extraPath
         let path = basePath </> joinPath (map dec8 extraPath)
         handleStaticFile sendContent path
      dec8  ByteString  String
      dec8 = cs  T.decodeUtf8

securityCheck  (Eq s, Show s, IsString s, Monad m)  [s]  m ()
securityCheck pathElems
    = when (any ( "..") pathElems)
          $ fail ("security error: "  show pathElems)