Settings.hs

{-# LANGUAGE OverloadedStrings #-}
module Breve.Settings where

import Control.Monad                   (when)
import System.Environment              (lookupEnv)
import System.Environment.XDG.BaseDir
import System.Directory                (doesFileExist)
import Data.Configurator
import Network.Wai.Handler.WarpTLS     (tlsSettings, TLSSettings)

data AppSettings = AppSettings
  { bindPort     :: Int
  , bindUrl      :: String
  , urlTable     :: FilePath
  , tlsSetts     :: TLSSettings
  }


createEmptyIfMissing :: FilePath -> IO ()
createEmptyIfMissing file = do
  exists <- doesFileExist file
  when (not exists) (writeFile file "")


settings :: IO AppSettings
settings = do
  urlsPath   <- getUserDataFile   "breve" ""
  configPath <- getUserConfigFile "breve" ""

  config <- load [Required configPath] 
  host   <- lookupDefault "localhost"                config "hostname"
  port   <- lookupDefault 3000                       config "port"    
  cert   <- lookupDefault "/usr/share/tls/breve.crt" config "cert"
  key    <- lookupDefault "/usr/share/tls/breve.key" config "key"
  urls   <- lookupDefault urlsPath                   config "urltable"

  createEmptyIfMissing urls

  let base = "https://" ++ host
      url  = if port == 443
               then base
               else base ++ ":" ++ show port

  return AppSettings
    { bindPort = port
    , bindUrl  = url ++ "/"
    , urlTable = urls
    , tlsSetts = tlsSettings cert key
    }