Add ini-like config support

src/Breve/Common.hs

@@ -7,26 +7,57 @@ import Control.Applicative
 import Control.Monad.IO.Class          (liftIO)
 import Text.Printf                     (printf)
 import System.Environment              (lookupEnv)
+import System.Environment.XDG.BaseDir
+import System.Directory                (doesFileExist)
+import Data.TConfig
 
 import Web.Simple.Templates
 import Network.Wai.Handler.Warp
 
-data AppSettings = AppSettings { }
+data ServerSettings = ServerSettings
+  { bindPort     :: Int
+  , bindHostname :: String
+  , bindUrl      :: String
+  , urlTable     :: FilePath
+  , warpSettings :: Settings
+  } deriving Show
 
-serverSettings :: IO (String, Settings)
-serverSettings = do
-  port <- maybe  3000       read <$> lookupEnv "PORT"
-  host <- maybe "localhost" id   <$> lookupEnv "HOSTNAME"
-  let opts = setPort port defaultSettings
-      url  = if port == 80
-             then printf "http://%s/"    host
-             else printf "http://%s:%d/" host port
-  return (url, opts)
-
-newAppSettings :: IO AppSettings
-newAppSettings = return AppSettings
+data AppSettings = AppSettings {}
 
 instance HasTemplates IO AppSettings where
   defaultLayout = do
     main <- liftIO (getDataFileName "layouts/main.html")
     Just <$> getTemplate main
+
+
+newAppSettings :: IO AppSettings
+newAppSettings = return AppSettings
+
+createEmptyIfMissing :: FilePath -> IO FilePath
+createEmptyIfMissing file = do
+  exists <- doesFileExist file
+  if not exists
+    then writeFile file "" >> return file
+    else return file
+
+newServerSettings :: IO ServerSettings
+newServerSettings = do
+  urlsPath   <- getUserDataFile   "breve" ""
+  configPath <- getUserConfigFile "breve" ""
+  
+  config <- readConfig =<< createEmptyIfMissing configPath
+  let host = maybe "localhost" id   (getValue "hostname" config)
+      port = maybe 3000        read (getValue "port"     config)
+      urls = maybe urlsPath    id   (getValue "urltable" config)
+
+  createEmptyIfMissing urls
+
+  return ServerSettings
+    { bindPort     = port
+    , bindHostname = host
+    , bindUrl      = if port == 80
+                       then printf "http://%s/"    host
+                       else printf "http://%s:%d/" host port
+    , urlTable     = urls
+    , warpSettings = setPort port defaultSettings
+    }