--- |The CommandLine module handles parsing of the command-line options.
--- It should more or less be a black box, providing Main with only the
--- information it requires.
+-- | The CommandLine module handles parsing of the command-line
+-- options. It should more or less be a black box, providing Main
+-- with only the information it requires.
module CommandLine
-( heartbeat,
+( get_cfg,
help_set,
help_text,
- ignore_replies_set,
- ignore_retweets_set,
- from_email_address,
- to_email_address,
parse_errors,
parse_usernames
) where
-import Data.Maybe (isJust, isNothing)
+import Data.Maybe (fromJust, isJust, isNothing)
import System.Console.GetOpt
import System.Environment (getArgs)
+import Configuration (Cfg(..))
-
--- |A record containing values for all available options.
+-- | A record containing values for all available options.
data Options = Options { opt_heartbeat :: Maybe Int,
opt_help :: Bool,
opt_ignore_replies :: Bool,
opt_ignore_retweets :: Bool,
opt_from :: Maybe String,
- opt_to :: Maybe String }
+ opt_to :: Maybe String,
+ opt_verbose :: Bool }
--- |Constructs an instance of Options, with each of its members set to
--- default values.
+-- | Constructs an instance of Options, with each of its members set
+-- to default values.
default_options :: Options
default_options = Options { opt_heartbeat = Just 600,
opt_help = False,
opt_ignore_replies = False,
opt_ignore_retweets = False,
opt_from = Nothing,
- opt_to = Nothing }
+ opt_to = Nothing,
+ opt_verbose = False }
--- |The options list that we construct associates a function with each
--- option. This function is responsible for updating an Options record
--- with the appropriate value.
+-- | The options list that we construct associates a function with
+-- each option. This function is responsible for updating an Options
+-- record with the appropriate value.
--
--- For more information and an example of this idiom, see,
+-- For more information and an example of this idiom, see,
--
--- <http://www.haskell.org/haskellwiki/High-level_option_handling_with_GetOpt>
+-- <http://www.haskell.org/haskellwiki/High-level_option_handling_with_GetOpt>
--
options :: [OptDescr (Options -> IO Options)]
options =
Option
['I']["ignore-retweets"]
(NoArg set_ignore_retweets)
- "Ignore retweets."
+ "Ignore retweets.",
+
+ Option
+ ['v']["verbose"]
+ (NoArg set_verbose)
+ "Be verbose about stuff."
]
set_ignore_replies opts =
return opts { opt_ignore_replies = True }
+set_verbose :: Options -> IO Options
+set_verbose opts =
+ return opts { opt_verbose = True }
+
set_to :: String -> Options -> IO Options
set_to arg opts = do
return opts { opt_to = Just arg }
return opts { opt_from = Just arg }
--- The usage header.
+-- | The usage header.
usage :: String
usage = "Usage: twat [-n heartbeat] [-t to_address] [-f from_address] <username1> [username2, [username3]...]"
--- The usage header, and all available flags (as generated by GetOpt)
+-- | Was the help option passed?
+help_set :: IO Bool
+help_set = do
+ opts <- parse_options
+ return (opt_help opts)
+
+-- | The usage header, and all available flags (as generated by GetOpt)
help_text :: String
help_text = usageInfo usage options
--- Return a list of options.
+-- | Return a list of options.
parse_options :: IO Options
parse_options = do
argv <- getArgs
-- | A list of parse errors relating to the heartbeat.
heartbeat_errors :: IO [String]
heartbeat_errors = do
- hb <- heartbeat
+ hb <- parse_heartbeat
if (isNothing hb)
then return ["\"heartbeat\" does not appear to be an integer."]
else return []
-- |Parse errors relating to the "To" address.
to_errors :: IO [String]
to_errors = do
- toaddr <- to_email_address
- fromaddr <- from_email_address
+ toaddr <- parse_to_address
+ fromaddr <- parse_from_address
if (isNothing toaddr) && (isJust fromaddr)
then return ["\"from\" address specified without \"to\" address."]
else return []
--- |Parse errors relating to the "From" address.
+-- | Parse errors relating to the "From" address.
from_errors :: IO [String]
from_errors = do
- toaddr <- to_email_address
- fromaddr <- from_email_address
+ toaddr <- parse_to_address
+ fromaddr <- parse_from_address
if (isJust toaddr) && (isNothing fromaddr)
then return ["\"to\" address specified without \"from\" address."]
else return []
--- |Format an error message for printing.
+-- | Format an error message for printing.
format_error :: String -> String
format_error err = "ERROR: " ++ err ++ "\n"
--- |Return a list of all parse errors.
+-- | Return a list of all parse errors.
parse_errors :: IO [String]
parse_errors = do
argv <- getArgs
errs_to ++
errs_from)
--- |Was the "help" option passed on the command line?
-help_set :: IO Bool
-help_set = do
- opts <- parse_options
- return (opt_help opts)
-
--- | Was the "ignore-replies" option passes on the command line?
-ignore_replies_set :: IO Bool
-ignore_replies_set = do
+-- | What's the heartbeat?
+parse_heartbeat :: IO (Maybe Int)
+parse_heartbeat = do
opts <- parse_options
- return (opt_ignore_replies opts)
+ return (opt_heartbeat opts)
--- | Was the "ignore-retweets" option passes on the command line?
-ignore_retweets_set :: IO Bool
-ignore_retweets_set = do
+-- | What "To" address was given on the command line?
+parse_to_address :: IO (Maybe String)
+parse_to_address = do
opts <- parse_options
- return (opt_ignore_retweets opts)
+ return (opt_to opts)
--- |What's the heartbeat?
-heartbeat :: IO (Maybe Int)
-heartbeat = do
+-- | What "From" address was given on the command line?
+parse_from_address :: IO (Maybe String)
+parse_from_address = do
opts <- parse_options
- return (opt_heartbeat opts)
-
--- |What "To" address was given on the command line?
-to_email_address :: IO (Maybe String)
-to_email_address = do
- opts <- parse_options
- return (opt_to opts)
-
--- |What "From" address was given on the command line?
-from_email_address :: IO (Maybe String)
-from_email_address = do
- opts <- parse_options
- return (opt_from opts)
+ return (opt_from opts)
--- |What usernames were passed on the command line?
+-- | What usernames were passed on the command line?
parse_usernames :: IO [String]
parse_usernames = do
argv <- getArgs
let (_, usernames, _) = getOpt Permute options argv
return usernames
+
+
+
+-- | Construct a Cfg object from the command line options assuming
+-- there are no errors.
+get_cfg :: IO Cfg
+get_cfg = do
+ opts <- parse_options
+ return Cfg { heartbeat = fromJust $ opt_heartbeat opts,
+ ignore_replies = opt_ignore_replies opts,
+ ignore_retweets = opt_ignore_retweets opts,
+ from_address = opt_from opts,
+ to_address = opt_to opts,
+ verbose = opt_verbose opts }
import Control.Concurrent (forkIO, threadDelay)
import Control.Monad (forever, when)
-import Data.Maybe (fromJust)
+import Data.List ((\\))
import System.Exit (ExitCode(..), exitWith)
import System.IO (hPutStrLn, stderr)
import CommandLine
+import Configuration (Cfg(..))
import ExitCodes
import Mail
import Twitter.Http
Nothing -> default_date
Just c -> c
--- |This is the main recursive loop. It takes a length of time to
--- delay (in seconds), 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 :: Int -> String -> Integer -> (Maybe Message) -> IO ()
-recurse delay username latest_status_id maybe_message = do
- thread_sleep delay
- xmldata <- get_user_new_statuses username latest_status_id
+-- | If the given Message is not Nothing, send a copy of it for every
+-- Status in the list.
+send_messages :: Maybe Message -> [Status] -> IO ()
+send_messages maybe_message statuses =
+ case maybe_message of
+ Nothing -> return ()
+ Just message -> do
+ default_date <- rfc822_now
+ let mfs = message_from_status message (default_date)
+ let messages = map mfs statuses
+ sendmail_results <- mapM sendmail messages
+ _ <- mapM print_sendmail_result sendmail_results
+ return ()
+
+
+
+-- | Display the number of skipped replies if ignore_replies is true
+-- and verbose is enabled.
+mention_replies :: Cfg -> [Status] -> IO ()
+mention_replies cfg ss = do
+ let replies = filter reply ss
+ when ((ignore_replies cfg) && (verbose cfg)) $ do
+ let countstr = show $ length replies
+ putStrLn $ "Ignoring " ++ countstr ++ " replies."
+
+
+-- | Display the number of skipped retweets if ignore_retweets is true
+-- and verbose is enabled.
+mention_retweets :: Cfg -> [Status] -> IO ()
+mention_retweets cfg ss = do
+ let retweets = filter retweet ss
+ when ((ignore_retweets cfg) && (verbose cfg)) $ do
+ let countstr = show $ length retweets
+ putStrLn $ "Ignoring " ++ countstr ++ " retweets."
+
+
+
+-- | Filter out replies/retweets based on the configuration.
+filter_statuses :: Cfg -> [Status] -> [Status]
+filter_statuses cfg ss =
+ good_statuses
+ where
+ replies = filter reply ss
+ retweets = filter retweet ss
- -- Parsing an empty result can blow up. Just pretend there are
- -- no new statuses in that case.
- let new_statuses = case xmldata of
- Just xml -> parse_statuses xml
- Nothing -> []
+ good_statuses' = case (ignore_replies cfg) of
+ True -> ss \\ replies
+ False -> ss
- case (length new_statuses) of
- 0 ->
- recurse delay username latest_status_id maybe_message
- _ -> do
- let new_latest_status_id = get_max_status_id new_statuses
- _ <- mapM (putStrLn . pretty_print) new_statuses
+ good_statuses = case (ignore_retweets cfg) of
+ True -> good_statuses' \\ retweets
+ False -> good_statuses'
- case maybe_message of
- Nothing -> do
- recurse delay username new_latest_status_id maybe_message
- return ()
- Just message -> do
- default_date <- rfc822_now
- let messages = map (message_from_status message (default_date)) new_statuses
- sendmail_results <- mapM sendmail messages
- _ <- mapM print_sendmail_result sendmail_results
- recurse delay 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.
+-- | This is the main recursive loop. It takes a the configuration, 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 :: Cfg -> String -> Integer -> (Maybe Message) -> IO ()
+recurse cfg username latest_status_id maybe_message = do
+ thread_sleep (heartbeat cfg)
+ xmldata <- get_user_new_statuses username latest_status_id
+
+ -- Parsing an empty result can blow up. Just pretend there are
+ -- no new statuses in that case.
+ let new_statuses = case xmldata of
+ Just xml -> parse_statuses xml
+ Nothing -> []
+
+ case (length new_statuses) of
+ 0 ->
+ do_recurse latest_status_id
+ _ -> do
+
+ mention_replies cfg new_statuses
+ mention_retweets cfg new_statuses
+
+ let good_statuses = filter_statuses cfg new_statuses
+
+ _ <- mapM (putStrLn . pretty_print) good_statuses
+
+ send_messages maybe_message good_statuses
+
+ let new_latest_status_id = get_max_status_id new_statuses
+ do_recurse new_latest_status_id
+
+ where
+ -- This lets us write all of these parameters once rather
+ -- than... more than once.
+ do_recurse :: Integer -> IO ()
+ do_recurse lsi = recurse cfg username lsi maybe_message
+
+
+-- | 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 :: Int -> String -> IO Integer
get_latest_status_id delay 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 :: Int -> Maybe Message -> String -> IO ()
-run_twat delay message username = do
- latest_status_id <- get_latest_status_id delay username
- recurse delay username latest_status_id message
+-- | 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 :: Cfg -> Maybe Message -> String -> IO ()
+run_twat cfg msg username = do
+ latest_status_id <- get_latest_status_id (heartbeat cfg) username
+ recurse cfg username latest_status_id msg
return ()
+
+-- | Take advantage of the Maybe monad to only return a message when
+-- we have both a "to" and "from" address.
+construct_message :: Cfg -> Maybe Message
+construct_message cfg = do
+ to_addr <- to_address cfg
+ from_addr <- from_address cfg
+ return $ make_msg to_addr from_addr
+ where
+ make_msg t f = Message { headers = default_headers,
+ body = "",
+ subject = "",
+ to = t,
+ from = f }
+
-- |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.
-- Next, check to see if the 'help' option was passed to the
-- program. If it was, display the help, and exit successfully.
- help_opt_set <- help_set
- when help_opt_set $ do
- putStrLn help_text
- exitWith ExitSuccess
+ help <- help_set
+ when (help) $ do
+ putStrLn help_text
+ exitWith ExitSuccess
+ -- Get the list of usernames.
usernames <- parse_usernames
+ -- And a Cfg object.
+ cfg <- get_cfg
+
-- If we have both a "To" and "From" address, we'll create a
-- message object to be passed to all of our threads.
- to_address <- to_email_address
- from_address <- from_email_address
- let message = case to_address of
- Nothing -> Nothing
- Just toaddr ->
- case from_address of
- Nothing -> Nothing
- Just fromaddr ->
- Just (Message { headers = default_headers,
- body = "",
- subject = "",
- to = toaddr,
- from = fromaddr })
-
- -- This should be safe since we checked for parse errors earlier.
- delay <- fmap fromJust heartbeat
+ let message = construct_message cfg
-- Execute run_twat on each username in a new thread.
- _ <- mapM (forkIO . (run_twat delay message)) usernames
+ let run_twat_curried = run_twat cfg message
+ _ <- mapM (forkIO . run_twat_curried) usernames
_ <- 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 delay
+ thread_sleep (heartbeat cfg)
return ()
--- |A debugging tool that will parse, print, and email a single status
--- (given by its id).
+-- | 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