src/Configuration.hs

   1 -- | This module defines the 'Cfg' type, which is just a wrapper
   2 --   around all of the configuration options we accept on the command
   3 --   line. We thread this throughout the rest of the program.
   4 --
   5
   6 module Configuration (
   7   Cfg(..),
   8   default_config,
   9   merge_optional
  10 )
  11 where
  12
  13 import qualified OptionalConfiguration as OC
  14 import Usernames
  15
  16 data Cfg =
  17   Cfg { consumer_key :: String,
  18         consumer_secret :: String,
  19         access_token :: String,
  20         access_secret :: String,
  21         heartbeat :: Int,
  22         ignore_replies :: Bool,
  23         ignore_retweets :: Bool,
  24         sendmail_path :: String,
  25         from_address :: Maybe String,
  26         to_address :: Maybe String,
  27         verbose :: Bool,
  28         usernames :: Usernames }
  29     deriving (Show)
  30
  31
  32 default_config :: Cfg
  33 default_config =
  34   Cfg { consumer_key = "",
  35         consumer_secret = "",
  36         access_token = "",
  37         access_secret = "",
  38         heartbeat = 600,
  39         ignore_replies = False,
  40         ignore_retweets = False,
  41         sendmail_path = "/usr/sbin/sendmail",
  42         from_address = Nothing,
  43         to_address = Nothing,
  44         verbose = False,
  45         usernames = Usernames [] }
  46
  47 merge_optional :: Cfg -> OC.OptionalCfg -> Cfg
  48 merge_optional cfg opt_cfg =
  49   Cfg
  50     (merge (consumer_key cfg) (OC.consumer_key opt_cfg))
  51     (merge (consumer_secret cfg) (OC.consumer_secret opt_cfg))
  52     (merge (access_token cfg) (OC.access_token opt_cfg))
  53     (merge (access_secret cfg) (OC.access_secret opt_cfg))
  54     (merge (heartbeat cfg) (OC.heartbeat opt_cfg))
  55     (merge (ignore_replies cfg) (OC.ignore_replies opt_cfg))
  56     (merge (ignore_retweets cfg) (OC.ignore_retweets opt_cfg))
  57     (merge (sendmail_path cfg) (OC.sendmail_path opt_cfg))
  58     (merge' (from_address cfg) (OC.from_address opt_cfg))
  59     (merge' (to_address cfg) (OC.to_address opt_cfg))
  60     (merge (verbose cfg) (OC.verbose opt_cfg))
  61     all_usernames
  62   where
  63     merge :: a -> Maybe a -> a
  64     merge x Nothing  = x
  65     merge _ (Just y) = y
  66
  67     -- Used for the to/from address
  68     merge' :: Maybe a -> Maybe a -> Maybe a
  69     merge' Nothing Nothing = Nothing
  70     merge' (Just x) Nothing  = Just x
  71     merge' Nothing (Just x)  = Just x
  72     merge' (Just _) (Just y) = Just y
  73
  74     -- If there are any optional usernames, use only those.
  75     all_usernames = if (null (get_usernames (OC.usernames opt_cfg)))
  76                     then (usernames cfg)
  77                     else (OC.usernames opt_cfg)