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
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
+-- |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
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
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 ()