Clean up imports.

[dead/halcyon.git] / src / Mail.hs

diff --git a/src/Mail.hs b/src/Mail.hs
index 2b5445c4ddcbd96020ddb2010b035db1235699d7..3f519ccd8f0d0e22714a248a6595af378ca947eb 100644 (file)
--- a/src/Mail.hs
+++ b/src/Mail.hs
@@ -1,16 +1,27 @@
-module Mail
+-- |Email functions and data types.
+
+module Mail (
+  Message(..),
+  default_headers,
+  print_sendmail_result,
+  rfc822_now,
+  sendmail )
 where
 
-import Control.Concurrent
-import Control.Concurrent.MVar
-import Control.Exception (evaluate)
-import Data.List (intercalate)
-import System.Exit
-import System.Process
-import System.IO
+import Control.Concurrent ( forkIO, newEmptyMVar, putMVar, readMVar )
+import Control.Exception ( evaluate )
+import Control.Monad ( liftM )
+import Data.List ( intercalate )
+import Data.Time ( formatTime, getZonedTime )
+import System.Exit ( ExitCode(..) )
+import System.Locale ( defaultTimeLocale, rfc822DateFormat )
+import System.Process ( runInteractiveProcess, waitForProcess )
+import System.IO ( hClose, hGetContents, hPutStr )
+
 
 type Header = String
 
+-- | A crude model of an RFC821 email message.
 data Message = Message { headers :: [Header],
                          subject :: String,
                          body    :: String,
@@ -18,23 +29,52 @@ data Message = Message { headers :: [Header],
                          to      :: String }
              deriving (Eq)
 
+-- | The default headers attached to each message.  The MIME junk is
+--   needed for UTF-8 to work properly. Note that your mail server
+--   should support the 8BITMIME extension.
+default_headers :: [Header]
+default_headers = ["MIME-Version: 1.0",
+                   "Content-Type: text/plain; charset=UTF-8",
+                   "Content-Transfer-Encoding: 8bit"]
+
+-- | Showing a message will print it in roughly RFC-compliant
+--   form. This form is sufficient for handing the message off to
+--   sendmail (or compatible).
 instance Show Message where
-    show m =
-        concat [ if (length (headers m) == 0) then "" else (intercalate "\n" (headers m)) ++ "\n",
-                 "Subject: " ++ (subject m) ++ "\n",
-                 "From: " ++ (from m) ++ "\n",
-                 "To: " ++ (to m) ++ "\n",
-                 "\n",
-                 (body m) ]
-
-        
-sendmail :: Message -> IO (String, String, ExitCode)
-sendmail message = do
+  show m =
+    concat [ formatted_headers,
+             "Subject: " ++ (subject m) ++ "\n",
+             "From: " ++ (from m) ++ "\n",
+             "To: " ++ (to m) ++ "\n",
+             "\n",
+             (body m) ]
+    where
+      formatted_headers =
+        if null (headers m)
+        then ""
+        else (intercalate "\n" (headers m)) ++ "\n"
+
+
+
+-- | Constructs a 'String' in RFC822 date format for the current
+--   date/time.
+rfc822_now :: IO String
+rfc822_now =
+  liftM (formatTime defaultTimeLocale rfc822DateFormat) getZonedTime
+
+
+
+
+-- |Takes a message as an argument, and passes it to the system's
+-- sendmail (or compatible) binary.
+sendmail :: FilePath -> Message -> IO (String, String, ExitCode)
+sendmail sendmail_path message = do
   let sendmail_args = ["-f",
-                       (from message)]
+                       (from message),
+                       (to message)]
 
   (inh, outh, errh, ph) <-
-      runInteractiveProcess "/usr/bin/sendmail" sendmail_args Nothing Nothing
+      runInteractiveProcess sendmail_path sendmail_args Nothing Nothing
 
   outm <- newEmptyMVar
   outs <- hGetContents outh
@@ -42,9 +82,9 @@ sendmail message = do
   errm <- newEmptyMVar
   errs <- hGetContents errh
 
-  forkIO $ hPutStr inh (show message) >> hClose inh
-  forkIO $ evaluate (length outs) >> putMVar outm ()
-  forkIO $ evaluate (length errs) >> putMVar errm ()
+  _ <- forkIO $ hPutStr inh (show message) >> hClose inh
+  _ <- forkIO $ evaluate (length outs) >> putMVar outm ()
+  _ <- forkIO $ evaluate (length errs) >> putMVar errm ()
 
   readMVar outm
   readMVar errm
@@ -53,10 +93,13 @@ sendmail message = do
   return (outs, errs, ec)
 
 
+-- |The 'sendmail' function returns a three-tuple of its outputs,
+-- errors, and exit codes.  This function pretty-prints one of those
+-- three-tuples.
 print_sendmail_result :: (String, String, ExitCode) -> IO ()
-print_sendmail_result (outs, errs, ec) = do
-    case ec of
-      ExitSuccess -> return ()
-      _ -> putStrLn $ concat ["Output: " ++ outs,
-                              "\nErrors: " ++ errs,
-                              "\nExit Code: " ++ (show ec)]
+print_sendmail_result (outs, errs, ec) =
+  case ec of
+    ExitSuccess -> return ()
+    _ -> putStrLn $ concat ["Output: " ++ outs,
+                            "\nErrors: " ++ errs,
+                            "\nExit Code: " ++ (show ec)]