From ef95ac393a1715550120770af034121ac02b1a0d Mon Sep 17 00:00:00 2001
From: Laura <the-ceo-of-antifa@protonmail.com>
Date: Fri, 3 Feb 2023 22:54:25 +0100
Subject: Improved handling of rate limit.

Commands can now return	True or	False to specify whether they
should count towards the rate limit. Some non-spammy commands
are set	to always false, while sending a file will only	count
if the file could actually be sent. Commands can also now be
sent immediately after miaowe startup, without an initial delay.
---
 miaowe.hs | 58 ++++++++++++++++++++++++++++++++++++----------------------
 1 file changed, 36 insertions(+), 22 deletions(-)

diff --git a/miaowe.hs b/miaowe.hs
index e2be098..61b161b 100644
--- a/miaowe.hs
+++ b/miaowe.hs
@@ -19,6 +19,7 @@
 -}
 
 import Data.Bits
+import Data.Bool
 import qualified Data.ByteString as S
 import qualified Data.ByteString.Char8 as S.Char8
 import qualified Data.ByteString.Internal as S.Internal
@@ -66,6 +67,9 @@ helpString = "Commands available: Code; Help; List. \
 Anything else is interpreted as a file name."
 #endif
 
+-- Minimum time between spammy commands.
+minimumDelay = 30
+
 ctrlC = [toEnum 03] :: String
 ctrlO = [toEnum 15] :: String
 ctrlV = [toEnum 22] :: String
@@ -215,58 +219,68 @@ sendFile channel path = S.readFile path
                         lines .
                         S.Char8.unpack
 
-trySendFile :: IrcChannel -> FilePath -> IO ()
+trySendFile :: IrcChannel -> FilePath -> IO Bool
 trySendFile channel path = (doesFileExist (path)
                             >>= (\b ->
                                     if b
                                     then
                                       sendFile channel (path)
+                                      >> return True
                                     else
                                       sendToChannel channel
                                       "No such file or command."
-                                    >> hFlush stdout))
+                                    >> hFlush stdout
+                                    >> return False))
 
 #ifdef FORTUNE
 getFortune :: IO String
 getFortune = readCreateProcess ((shell "fortune -e | cowsay -b")) ""
 #endif
 
-doCommand :: IrcChannel -> MircString -> IO ()
+-- Takes a channel and command, return True if
+-- command should count towards rate limiting,
+-- False if not.
+doCommand :: IrcChannel -> MircString -> IO Bool
 doCommand channel command =
   case map toLower ((words command)!!4) of
     "list" -> listDirectory "."
-              >>= sendToChannel channel .
-              intercalate "\n"
+              >>= sendToChannel channel . intercalate "\n"
+              >> return True
     "code" -> sendToChannel channel codeUrl
+              >> return False
     "help" -> sendToChannel channel helpString
+              >> return False
 #ifdef FORTUNE
     "fortune" -> getFortune
                  >>= sendToChannel channel
+                 >> return True
 #endif
     _ -> (if isInfixOf "/" ((words command)!!4)
           then
-            sendToChannel channel
-            "Only PWD please."
+            sendToChannel channel "Only PWD please."
+           >> return False
           else
-            trySendFile channel
-            ((words command)!!4))
+            trySendFile channel ((words command)!!4))
 
+-- Subtracts t from the current time to get the time t ago.
 subtractPresent :: NominalDiffTime -> IO UTCTime
 subtractPresent t = getCurrentTime >>= \c -> return $ addUTCTime (-t) c
 
+-- Takes channel, command, and time elapsed since last command.
+-- Returns the time to use for counting, either the current time,
+-- or the one of the previous command it throttling is not wished.
 processCommand :: IrcChannel -> MircString -> NominalDiffTime -> IO UTCTime
-processCommand channel command timeElapsed | timeElapsed < 30 =
-                                             sendToChannel channel
-                                             "Not so quick, partner"
-                                             >> subtractPresent timeElapsed
-                                           | length (words command) < 5 =
-                                             sendToChannel channel
-                                             "You need to specify \
+processCommand channel command timeElapsed
+  | timeElapsed < minimumDelay =
+      sendToChannel channel "Not so quick, partner"
+      >> subtractPresent timeElapsed
+  | length (words command) < 5 =
+      sendToChannel channel "You need to specify \
 a command."
-                                             >> subtractPresent timeElapsed
-                                           | otherwise =
-                                             doCommand channel command
-                                             >> getCurrentTime
+      >> subtractPresent timeElapsed
+  | otherwise =
+      doCommand channel command
+      >>= bool (subtractPresent timeElapsed) getCurrentTime
 
 commandChannel :: String -> String
 commandChannel command = (words command)!!2
@@ -280,7 +294,7 @@ mainLoop channel time = waitForCommand
                                               (diffUTCTime t time)
                                else return time)
                               >>= mainLoop channel
-                        
+
 
 main :: IO ()
 main =
@@ -297,4 +311,4 @@ main =
         joinChannel (args!!0)
         >> hFlush stdout
         >> getCurrentTime
-        >>= mainLoop (args!!0)
+        >>= \t -> mainLoop (args!!0) (addUTCTime (-minimumDelay) t)
-- 
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