From: Michael Orlitzky <michael@orlitzky.com>
Date: Fri, 20 Dec 2013 03:19:54 +0000 (-0500)
Subject: Move FeedHosts under the TSN namespace.
X-Git-Tag: 0.0.2~41
X-Git-Url: https://gitweb.michael.orlitzky.com/?a=commitdiff_plain;h=95e23e65db31cf51c9f207a6b447da19920ee1a1;p=dead%2Fhtsn.git

Move FeedHosts under the TSN namespace.
Undo the global config file check.
Use a cross-platform method of getting the user's home directory.
Clarify some old comments, and add new ones.
---

diff --git a/src/Configuration.hs b/src/Configuration.hs
index a382a9d..71dbbc9 100644
--- a/src/Configuration.hs
+++ b/src/Configuration.hs
@@ -9,8 +9,8 @@ where
 
 import System.Console.CmdArgs.Default (Default(..))
 
-import FeedHosts (FeedHosts(..))
 import qualified OptionalConfiguration as OC (OptionalConfiguration(..))
+import TSN.FeedHosts (FeedHosts(..))
 
 data Configuration =
   Configuration {
diff --git a/src/Main.hs b/src/Main.hs
index e1cb91a..3749812 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -36,18 +36,14 @@ import ExitCodes (
   exit_no_feed_hosts,
   exit_no_password,
   exit_no_username )
-import FeedHosts (FeedHosts(..))
 import qualified OptionalConfiguration as OC (
   OptionalConfiguration(..),
   from_rc )
-import Terminal (hPutRedLn, putGreenLn)
+import Terminal (putGreenLn, report_error)
+import TSN.FeedHosts (FeedHosts(..))
 import TSN.Xml (parse_xmlfid, xml_prologue)
 
 
-report_error :: String -> IO ()
-report_error = hPutRedLn stderr
-
-
 recv_line :: Handle -> IO String
 recv_line h = do
   line <- hGetLine h
diff --git a/src/OptionalConfiguration.hs b/src/OptionalConfiguration.hs
index ea7a678..f636a17 100644
--- a/src/OptionalConfiguration.hs
+++ b/src/OptionalConfiguration.hs
@@ -2,12 +2,11 @@
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE OverloadedStrings #-}
 
--- | The program will parse ~/.htsnrc for any available configuration
---   directives, resulting in an OptionalConfiguration. The
---   command-line arguments will be used to create another
---   OptionalConfiguration, and the two will be merged. Finally, a
---   def :: Configuration will be updated from the merged
---   OptionalConfigurations.
+-- | An OptionalConfiguration is just like a 'Configuration', except
+--   all of its fields are optional. The user can set options in two
+--   places: the command-line, and a configuration file. Obviously if
+--   a parameter is set in one place, it doesn't need to be set in the
+--   other. Thus, the latter needs to be optional.
 --
 
 module OptionalConfiguration (
@@ -23,8 +22,12 @@ import Data.Data (Data)
 import Data.Maybe (fromMaybe)
 import Data.Monoid (Monoid(..))
 import Data.Typeable (Typeable)
+import System.Directory (getHomeDirectory)
+import System.FilePath ( (</>) )
+import System.IO.Error (catchIOError)
 
-import FeedHosts (FeedHosts(..))
+import Terminal (report_error)
+import TSN.FeedHosts (FeedHosts(..))
 
 
 -- | The same as Configuration, except everything is optional. It's easy to
@@ -40,7 +43,20 @@ data OptionalConfiguration =
     username :: Maybe String }
     deriving (Show, Data, Typeable)
 
+
+-- | The Monoid instance for these lets us "combine" two
+--   OptionalConfigurations. The "combine" operation that we'd like to
+--   perform is, essentially, to mash them together. So if we have two
+--   OptionalConfigurations, each half full, we could combine them
+--   into one big one.
+--
+--   One of the two must take precedence during this mashing, and we
+--   choose the second one for no reason.
+--
+--   This is used to merge command-line and config-file settings.
+--
 instance Monoid OptionalConfiguration where
+  -- | An empty OptionalConfiguration.
   mempty = OptionalConfiguration
              (FeedHosts [])
              Nothing
@@ -48,6 +64,7 @@ instance Monoid OptionalConfiguration where
              Nothing
 
 
+  -- | Combine @cfg1@ and @cfg2@, giving precedence to @cfg2@.
   cfg1 `mappend` cfg2 =
     OptionalConfiguration
       all_feed_hosts
@@ -67,10 +84,27 @@ instance Monoid OptionalConfiguration where
                     then cfg1
                     else cfg2
 
+
+-- | Obtain an OptionalConfiguration from the file ".htsnrc" in the
+--   user's home directory.
+--
+--   We make an attempt at cross-platform compatibility; we will try
+--   to find the correct directory even on Windows. But if the call
+--   to getHomeDirectory fails for whatever reason, we fall back to
+--   using the environment variable $HOME.
+--
 from_rc :: IO OptionalConfiguration
 from_rc = do
-  cfg <- DC.load [ DC.Optional "/etc/htsnrc",
-                   DC.Optional "$(HOME)/.htsnrc" ]
+  -- After some thought, the "global" /etc/htsnrc configuration file
+  -- was left out. Since each config file needs a password, and this
+  -- should be run by a dedicated user anyway, the global file does
+  -- not serve much purpose. It could also be a security risk (visible
+  -- password) if the admin screws up.
+  home <- catchIOError getHomeDirectory (\e -> do
+                                           report_error (show e)
+                                           return "$(HOME)")
+  let user_config_path = home </> ".htsnrc"
+  cfg <- DC.load [ DC.Optional user_config_path ]
   cfg_password <- DC.lookup cfg "password"
   cfg_output_directory <- DC.lookup cfg "output_directory"
   cfg_username <- DC.lookup cfg "username"
diff --git a/src/FeedHosts.hs b/src/TSN/FeedHosts.hs
similarity index 61%
rename from src/FeedHosts.hs
rename to src/TSN/FeedHosts.hs
index 43bab17..0b2056e 100644
--- a/src/FeedHosts.hs
+++ b/src/TSN/FeedHosts.hs
@@ -1,10 +1,14 @@
 {-# LANGUAGE DeriveDataTypeable #-}
 
 -- | A newtype around a list of Strings which represent the feed
--- hosts. This is all to avoid an orphan instance of Configured for
--- [String] if we had defined one in e.g. OptionalConfiguration.
+--   hosts. This is all to avoid an orphan instance of Configured for
+--   [String] if we had defined one in e.g. OptionalConfiguration.
 --
-module FeedHosts
+--   This was placed under the "TSN" namespace because its Default
+--   instance is specific to TSN, even though otherwise it's just a
+--   list of strings.
+--
+module TSN.FeedHosts
 where
 
 -- DC is needed only for the DCT.Configured instance of String.
@@ -19,8 +23,11 @@ newtype FeedHosts =
   FeedHosts { get_feed_hosts :: [String] }
     deriving (Data, Show, Typeable)
 
-
 instance Default FeedHosts where
+  -- | The default list of feed hosts. These were found by checking
+  --   PTR records in the neighborhood of the IP address in use. There
+  --   is a feed4.sportsnetwork.com, but it was not operational when
+  --   this was written.
   def = FeedHosts ["feed1.sportsnetwork.com",
                    "feed2.sportsnetwork.com",
                    "feed3.sportsnetwork.com"]
diff --git a/src/Terminal.hs b/src/Terminal.hs
index e9b59dc..cd35bf0 100644
--- a/src/Terminal.hs
+++ b/src/Terminal.hs
@@ -1,6 +1,6 @@
 module Terminal (
-  hPutRedLn,
-  putGreenLn)
+  putGreenLn,
+  report_error)
 where
 
 import Control.Monad.IO.Class (MonadIO(..))
@@ -10,7 +10,7 @@ import System.Console.ANSI (
   ColorIntensity( Vivid ),
   ConsoleLayer( Foreground ),
   setSGR )
-import System.IO ( Handle, hPutStrLn )
+import System.IO ( Handle, hPutStrLn, stderr )
 
 -- | Perform a computation (anything in MonadIO) with the given
 --   graphics mode(s) enabled. Revert to the previous graphics mode
@@ -39,3 +39,7 @@ hPutRedLn h = with_color Red . hPutStrLn h
 --   consistency with e.g. putStrLn.
 putGreenLn :: String -> IO ()
 putGreenLn = with_color Green . putStrLn
+
+-- | Report an error (to stderr).
+report_error :: String -> IO ()
+report_error = hPutRedLn stderr