formatter: Implement truncation of joined/quit users in netsplits

The list of users that have quit or joined after a netsplit can become
quite large. Quassel itself cuts reporting off after printing 15 users,
so let's follow that. Note that this will not affect queries - the
search is performed against the whole netsplit message.

1 files changed, 14 insertions, 13 deletions

diff --git a/quarg/quassel/formatter.py b/quarg/quassel/formatter.py
index 59793fc..ed33719 100644
--- a/quarg/quassel/formatter.py
+++ b/quarg/quassel/formatter.py
@@ -76,20 +76,21 @@ def parse_netsplit(splitmsg):
     # ... however, the last element contains the split servers instead
     servers = elements.pop().split(' ', 1)
 
-    # TODO: This takes ages if the netsplit was large
-    users = [User.from_sender(e) for e in elements]
+    # This list can be unwieldily large. Mirror quassel's behaviour and cut off
+    # after printing 15 users. If there were any more users than this, have
+    # rest contain a value larger than 0
+    users = [User.from_sender(e) for e in elements[0:15]]
+    rest = max(0, len(elements) - 15)
 
-    return users, servers
+    return users, servers, rest
 
-def format_netsplit_join(msg):
-    users, (srv_left, srv_right) = parse_netsplit(msg.message)
-    have_joined = ', '.join(user.nick for user in users)
-    return f'=> Netsplit between {srv_left} and {srv_right} ended. Users joined: {have_joined}'
+def format_netsplit(quit, msg):
+    users, (srv_left, srv_right), rest = parse_netsplit(msg.message)
+    affected = ', '.join(user.nick for user in users) + (f' ({rest} more)' if rest else '')
+    if quit:
+        return f'<= Netsplit between {srv_left} and {srv_right}. Users quit: {affected}'
+    return f'=> Netsplit between {srv_left} and {srv_right} ended. Users joined: {affected}'
 
-def format_netsplit_quit(msg):
-    users, (srv_left, srv_right) = parse_netsplit(msg.message)
-    have_quit = ', '.join(user.nick for user in users)
-    return f'<= Netsplit between {srv_left} and {srv_right}. Users quit: {have_quit}'
 
 def fmt(string):
     return partial(lambda string, msg: string.format(**msg._asdict()), string)
@@ -110,7 +111,7 @@ FORMATTERS = {
         MessageType.ERROR:         format_generic,
         MessageType.DAYCHANGE:     format_generic,
         MessageType.TOPIC:         format_generic,
-        MessageType.NETSPLIT_JOIN: format_netsplit_join,
-        MessageType.NETSPLIT_QUIT: format_netsplit_quit,
+        MessageType.NETSPLIT_JOIN: partial(format_netsplit, False),
+        MessageType.NETSPLIT_QUIT: partial(format_netsplit, True),
         MessageType.INVITE:        format_generic,
 }