X-Git-Url: http://gitweb.michael.orlitzky.com/?p=dead%2Fhalcyon.git;a=blobdiff_plain;f=src%2FMain.hs;h=fc7966f9f1df518283cae1ce2705b1e1effb058e;hp=ac33b2bdc654ffe143e7aeaa548fc93413d64f63;hb=27c6a7e62a428ceb1d2a60d456b075feee196da9;hpb=53c26134670775854677470e402b8b41f19246d1

diff --git a/src/Main.hs b/src/Main.hs
index ac33b2b..fc7966f 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -14,21 +14,34 @@ import Twitter.Status
 import Twitter.User
 
 
--- The length of all calls to sleep, in seconds.
+-- |The length of all calls to sleep (or threadDelay), in seconds.
 heartbeat :: Int
 heartbeat = 600
 
+-- |A wrapper around threadDelay which takes seconds instead of
+-- microseconds as its argument.
 thread_sleep :: Int -> IO ()
-thread_sleep microseconds = do
-  let seconds = microseconds * (10 ^ (6 :: Int))
-  threadDelay seconds
+thread_sleep seconds = do
+  let microseconds = seconds * (10 ^ (6 :: Int))
+  threadDelay microseconds
 
 
-message_from_status :: Message -> Status -> Message
-message_from_status message status =
+-- |Given a 'Message', 'Status', and date, update that message's body
+-- and subject with the information contained in the status. Adds a
+-- /Date: / header, and returns the updated message.
+message_from_status :: Message -> String -> Status -> Message
+message_from_status message date status =
     message { subject = "Twat: " ++ (screen_name (user status)),
-              body    = (pretty_print status) }
+              body    = (pretty_print status),
+              headers = ((headers message) ++ ["Date: " ++ date])}
 
+
+-- |This is the main recursive loop. It takes a username, a
+-- latest_status_id, and optionally a 'Message' as arguments. The
+-- latest_status_id is the last status (that we know of) to be posted
+-- to username's Twitter account. If we find any newer statuses when
+-- we check, they are printed and optionally emailed (if a 'Message'
+-- was supplied). Then, the process repeats.
 recurse :: String -> Integer -> (Maybe Message) -> IO ()
 recurse username latest_status_id maybe_message = do
     thread_sleep heartbeat
@@ -45,20 +58,23 @@ recurse username latest_status_id maybe_message = do
         recurse username latest_status_id maybe_message
       _ -> do
         let new_latest_status_id = get_max_status_id new_statuses
-        mapM (putStrLn . pretty_print) new_statuses
+        _ <- mapM (putStrLn . pretty_print) new_statuses
 
         case maybe_message of
           Nothing -> do
              recurse username new_latest_status_id maybe_message
              return ()
           Just message -> do
-             let messages = map (message_from_status message) new_statuses
+             date_header <- construct_date_header
+             let messages = map (message_from_status message (date_header)) new_statuses
              sendmail_results <- mapM sendmail messages
-             mapM print_sendmail_result sendmail_results
+             _ <- mapM print_sendmail_result sendmail_results
              recurse username new_latest_status_id maybe_message
              return ()
 
 
+-- |Try continually to download username's timeline, and determine the
+-- latest status id to be posted once we have done so.
 get_latest_status_id :: String -> IO Integer
 get_latest_status_id username = do
   xmldata <- get_user_timeline username
@@ -77,6 +93,11 @@ get_latest_status_id username = do
 
 
 
+-- |This function wraps two steps. First, we need to find the latest
+-- status id posted by username. Once we have that, we can begin the
+-- recursive loop that checks for updates forever. The message
+-- argument is optional and is passed to recurse in case the updates
+-- should be emailed.
 run_twat :: Maybe Message -> String -> IO ()
 run_twat message username = do
   latest_status_id <- get_latest_status_id username
@@ -84,6 +105,9 @@ run_twat message username = do
   return ()
 
 
+-- |The main function just parses the command-line arguments and then
+-- forks off calls to 'run_twat' for each supplied username. After
+-- forking, main loops forever.
 main :: IO ()
 main = do
   errors <- parse_errors
@@ -114,19 +138,50 @@ main = do
                       case from_address of
                         Nothing -> Nothing
                         Just fromaddr ->
-                            Just (Message { headers = [],
+                            Just (Message { headers = default_headers,
                                             body = "",
                                             subject = "",
                                             to = toaddr,
                                             from = fromaddr })
 
   -- Execute run_twat on each username in a new thread.
-  mapM (forkIO . (run_twat message)) usernames
+  _ <- mapM (forkIO . (run_twat message)) usernames
 
-  forever $ do
+  _ <- forever $ do
     -- This thread (the one executing main) doesn't do anything,
     -- but when it terminates, so do all the threads we forked.
     -- As a result, we need to keep this thread on life support.
     thread_sleep heartbeat
 
   return ()
+
+
+-- |A debugging tool that will parse, print, and email a single status
+-- (given by its id).
+twat_single_status :: Integer -> (Maybe Message) -> IO ()
+twat_single_status the_status_id maybe_message = do
+    xmldata <- get_status the_status_id
+
+    -- Parsing an empty result can blow up. Just pretend there are
+    -- no new statuses in that case.
+    let statuses = case xmldata of
+                     Just xml -> parse_status xml
+                     Nothing  -> []
+
+    case (length statuses) of
+      0 -> do
+        putStrLn "No statuses returned."
+        return ()
+      _ -> do
+        _ <- mapM (putStrLn . pretty_print) statuses
+
+        case maybe_message of
+          Nothing -> do
+             putStrLn "No message object given."
+             return ()
+          Just message -> do
+             date_header <- construct_date_header
+             let messages = map (message_from_status message (date_header)) statuses
+             sendmail_results <- mapM sendmail messages
+             _ <- mapM print_sendmail_result sendmail_results
+             return ()