From 59d542bb7066000dd0330408029fe3e4feb4d966 Mon Sep 17 00:00:00 2001
From: Valentin Lorentz <valentin.lorentz@ens-lyon.fr>
Date: Fri, 15 May 2015 19:24:24 +0200
Subject: [PATCH] NickCapture & core: Add support for MONITOR. Closes GH-842.

---
 plugins/NickCapture/plugin.py | 24 +++++++++++++++++++++++-
 src/irclib.py                 | 33 +++++++++++++++++++++++++++++++++
 src/ircmsgs.py                | 13 +++++++++++++
 3 files changed, 69 insertions(+), 1 deletion(-)

diff --git a/plugins/NickCapture/plugin.py b/plugins/NickCapture/plugin.py
index 17b312204..974d50657 100644
--- a/plugins/NickCapture/plugin.py
+++ b/plugins/NickCapture/plugin.py
@@ -45,6 +45,12 @@ class NickCapture(callbacks.Plugin):
         self.__parent = super(NickCapture, self)
         self.__parent.__init__(irc)
         self.lastIson = 0
+        self.monitoring = []
+
+    def die(self):
+        for irc in self.monitoring:
+            nick = self._getNick(irc.network)
+            irc.unmonitor(nick)
         
     def _getNick(self, network):
         network_nick = conf.supybot.networks.get(network).nick()
@@ -60,10 +66,16 @@ class NickCapture(callbacks.Plugin):
                 # We used to check this, but nicksToHostmasks is never cleared
                 # except on reconnects, which can cause trouble.
                 # if nick not in irc.state.nicksToHostmasks:
-                self._ison(irc, nick)
+                if 'monitor' in irc.state.supported:
+                    if irc not in self.monitoring:
+                        irc.monitor(nick)
+                        self.monitoring.append(irc)
+                else:
+                    self._ison(irc, nick)
                 self.__parent.__call__(irc, msg)
 
     def _ison(self, irc, nick):
+        assert 'monitor' not in irc.state.supported
         if self.registryValue('ison'):
             now = time.time()
             if now - self.lastIson > self.registryValue('ison.period'):
@@ -95,6 +107,16 @@ class NickCapture(callbacks.Plugin):
             nick = self._getNick(irc.network)
             if nick:
                 self._sendNick(irc, nick)
+
+    def do731(self, irc, msg):
+        """This is sent by the MONITOR when a nick goes offline."""
+        nick = self._getNick(irc.network)
+        for target in msg.args[1].split(','):
+            if nick == target:
+                self._sendNick(irc, nick)
+                self.monitoring.remove(irc)
+                irc.unmonitor(nick)
+                break
 NickCapture = internationalizeDocstring(NickCapture)
 
 Class = NickCapture
diff --git a/src/irclib.py b/src/irclib.py
index 94380f9b2..1c743c058 100644
--- a/src/irclib.py
+++ b/src/irclib.py
@@ -666,6 +666,7 @@ class Irc(IrcCommandDispatcher):
         self._setNonResettingVariables()
         self._queueConnectMessages()
         self.startedSync = ircutils.IrcDict()
+        self.monitoring = ircutils.IrcDict()
 
     def isChannel(self, s):
         """Helper function to check whether a given string is a channel on
@@ -1041,6 +1042,38 @@ class Irc(IrcCommandDispatcher):
                         command='CAP',
                         args=('END',)))
 
+    def monitor(self, targets):
+        """Increment a counter of how many callbacks monitor each target;
+        and send a MONITOR + to the server if the target is not yet
+        monitored."""
+        if isinstance(targets, str):
+            targets = [targets]
+        not_yet_monitored = set()
+        for target in targets:
+            if target in self.monitoring:
+                self.monitoring[target] += 1
+            else:
+                not_yet_monitored.add(target)
+                self.monitoring[target] = 1
+        if not_yet_monitored:
+            self.queueMsg(ircmsgs.monitor('+', not_yet_monitored))
+        return not_yet_monitored
+
+    def unmonitor(self, targets):
+        """Decrements a counter of how many callbacks monitor each target;
+        and send a MONITOR - to the server if the counter drops to 0."""
+        if isinstance(targets, str):
+            targets = [targets]
+        should_be_unmonitored = set()
+        for target in targets:
+            self.monitoring[target] -= 1
+            if self.monitoring[target] == 0:
+                del self.monitoring[target]
+                should_be_unmonitored.add(target)
+        if should_be_unmonitored:
+            self.queueMsg(ircmsgs.monitor('-', should_be_unmonitored))
+        return should_be_unmonitored
+
     def do903(self, msg):
         log.info('%s: SASL authentication successful', self.network)
         self.queueMsg(ircmsgs.IrcMsg(command='CAP', args=('END',)))
diff --git a/src/ircmsgs.py b/src/ircmsgs.py
index 3a4453de4..45bf3104b 100644
--- a/src/ircmsgs.py
+++ b/src/ircmsgs.py
@@ -855,6 +855,19 @@ def ison(nick, prefix='', msg=None):
         prefix = msg.prefix
     return IrcMsg(prefix=prefix, command='ISON', args=(nick,), msg=msg)
 
+def monitor(subcommand, nicks=None, prefix='', msg=None):
+    if conf.supybot.protocols.irc.strictRfc():
+        assert isNick(nick), repr(nick)
+        assert subcommand in '+-CLS'
+        if subcommand in 'CLS':
+            assert nicks is None
+    if msg and not prefix:
+        prefix = msg.prefix
+    if not isinstance(nicks, str):
+        nicks = ','.join(nicks)
+    return IrcMsg(prefix=prefix, command='MONITOR', args=(subcommand, nicks),
+            msg=msg)
+
 def error(s, msg=None):
     return IrcMsg(command='ERROR', args=(s,), msg=msg)