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 Data.Monoid

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


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"    
  urls   <- lookupDefault urlsPath    config "urltable"

  createEmptyIfMissing urls

  let base = "http://" <> host
      url  = if port == 80
               then base
               else base <> ":" <> show port

  return AppSettings
    { bindPort = port
    , bindUrl  = url <> "/"
    , urlTable = urls
    }