From 47973319621991cabf2d2569fe93037e981bef8b Mon Sep 17 00:00:00 2001
From: vegax87 <vegax987@gmail.com>
Date: Sun, 15 Jan 2017 01:48:47 +0100
Subject: [PATCH] Basic implementation of LUSERS command

---
 CHANGELOG.md    |  1 +
 irc/commands.go |  4 ++++
 irc/help.go     |  9 +++++++++
 irc/server.go   | 35 +++++++++++++++++++++++++++++++++++
 4 files changed, 49 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d62a99b4..092f429c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,7 @@ New release of Oragono!
 * Added ARM build (for Raspberry PIs and similar).
 * Added automated connection throttling! See the new `connection-throttling` section in the config.
 * Added `KLINE` and `UNKLINE` commands. Complementing `DLINE`'s per-IP and per-network bans, this lets you ban masks from the server.
+* Added LUSERS command. It works for a single server for now (by @vegax87)
 
 ### Changed
 * Changed casemapping from "rfc7700" to "rfc7613", to match new draft spec.
diff --git a/irc/commands.go b/irc/commands.go
index 964eaca3..b3bb056c 100644
--- a/irc/commands.go
+++ b/irc/commands.go
@@ -116,6 +116,10 @@ var Commands = map[string]Command{
 		handler:   listHandler,
 		minParams: 0,
 	},
+	"LUSERS": {
+		handler:   lusersHandler,
+		minParams: 0,
+	},
 	"MODE": {
 		handler:   modeHandler,
 		minParams: 1,
diff --git a/irc/help.go b/irc/help.go
index a2227ed2..3dce40df 100644
--- a/irc/help.go
+++ b/irc/help.go
@@ -189,6 +189,15 @@ Shows information on the given channels (or if none are given, then on all
 channels). <elistcond>s modify how the channels are selected.`,
 		//TODO(dan): Explain <elistcond>s in more specific detail
 	},
+	"lusers": {
+		text: `LUSERS [ <mask> [ <target> ] ]
+
+Returns statistics about the size of the network.
+If called with no arguments, the statistics will reflect the entire network. 
+If <mask> is given, it will return only statistics reflecting the masked subset of the network. 
+If <target> is given, the command will be forwarded to <server> for evaluation.`,
+		//TODO(vegax87): Include network statistics and parameters
+	},
 	"mode": {
 		text: `MODE <target> [<modestring> [<mode arguments>...]]
 
diff --git a/irc/server.go b/irc/server.go
index 985aaa75..ee1447a9 100644
--- a/irc/server.go
+++ b/irc/server.go
@@ -1677,3 +1677,38 @@ func whowasHandler(server *Server, client *Client, msg ircmsg.IrcMessage) bool {
 	}
 	return false
 }
+
+// LUSERS [ <mask> [ <target> ] ]
+func lusersHandler(server *Server, client *Client, msg ircmsg.IrcMessage) bool {
+	//TODO(vegax87) Fix Unknown connections and additional parameters
+
+	var totalcount int
+	var invisiblecount int
+	var opercount int
+	var chancount int
+
+	server.clients.ByNickMutex.RLock()
+	defer server.clients.ByNickMutex.RUnlock()
+
+	for _, onlineusers := range server.clients.ByNick {
+		totalcount += 1
+		if onlineusers.flags[Invisible] {
+			invisiblecount += 1
+		}
+		if onlineusers.flags[Operator] {
+			opercount += 1
+		}
+	}
+
+	for chans := range server.channels {
+		//Little hack just to avoid "variable declared but not used" error
+		_ = chans
+		chancount += 1
+	}
+	client.Send(nil, server.name, RPL_LUSERCLIENT, client.nick, fmt.Sprintf("There are %d users and %d invisible on %d server(s)", totalcount, invisiblecount, 1))
+	client.Send(nil, server.name, RPL_LUSEROP, client.nick, fmt.Sprintf("%d operators online", opercount))
+	client.Send(nil, server.name, RPL_LUSERUNKNOWN, client.nick, "X unknown connection(s)")
+	client.Send(nil, server.name, RPL_LUSERCHANNELS, client.nick, fmt.Sprintf("%d channels formed", chancount))
+	client.Send(nil, server.name, RPL_LUSERME, client.nick, fmt.Sprintf("I have %d clients and %d servers", totalcount, 1))
+	return false
+}