From 7fde04ea9420d4a18ab9521496f999dd43cd5e37 Mon Sep 17 00:00:00 2001
From: delthas <delthas@dille.cc>
Date: Sat, 24 Jul 2021 20:52:03 +0200
Subject: [PATCH] Add support for extended-monitor

See: https://github.com/ircv3/ircv3-specifications/pull/466
---
 gencapdefs.py    |  6 ++++++
 irc/caps/defs.go |  7 ++++++-
 irc/client.go    |  9 ++++++++-
 irc/handlers.go  |  6 +++---
 irc/monitor.go   | 13 +++++++++++++
 5 files changed, 36 insertions(+), 5 deletions(-)

diff --git a/gencapdefs.py b/gencapdefs.py
index 48e734f2..b1d2ebf2 100644
--- a/gencapdefs.py
+++ b/gencapdefs.py
@@ -177,6 +177,12 @@ CAPDEFS = [
         url="https://github.com/ircv3/ircv3-specifications/pull/435",
         standard="draft IRCv3",
     ),
+    CapDef(
+        identifier="ExtendedMonitor",
+        name="draft/extended-monitor",
+        url="https://github.com/ircv3/ircv3-specifications/pull/466",
+        standard="draft IRCv3",
+    ),
 ]
 
 def validate_defs():
diff --git a/irc/caps/defs.go b/irc/caps/defs.go
index aa988812..7eea8867 100644
--- a/irc/caps/defs.go
+++ b/irc/caps/defs.go
@@ -7,7 +7,7 @@ package caps
 
 const (
 	// number of recognized capabilities:
-	numCapabs = 27
+	numCapabs = 28
 	// length of the uint64 array that represents the bitset:
 	bitsetLen = 1
 )
@@ -53,6 +53,10 @@ const (
 	// https://github.com/ircv3/ircv3-specifications/pull/362
 	EventPlayback Capability = iota
 
+	// ExtendedMonitor is the draft IRCv3 capability named "draft/extended-monitor":
+	// https://github.com/ircv3/ircv3-specifications/pull/466
+	ExtendedMonitor Capability = iota
+
 	// Languages is the proposed IRCv3 capability named "draft/languages":
 	// https://gist.github.com/DanielOaks/8126122f74b26012a3de37db80e4e0c6
 	Languages Capability = iota
@@ -135,6 +139,7 @@ var (
 		"draft/channel-rename",
 		"draft/chathistory",
 		"draft/event-playback",
+		"draft/extended-monitor",
 		"draft/languages",
 		"draft/multiline",
 		"draft/relaymsg",
diff --git a/irc/client.go b/irc/client.go
index 39013e68..a703592d 100644
--- a/irc/client.go
+++ b/irc/client.go
@@ -1025,6 +1025,13 @@ func (client *Client) Friends(capabs ...caps.Capability) (result map[*Session]em
 	return
 }
 
+// Friends refers to clients that share a channel or extended-monitor this client.
+func (client *Client) FriendsMonitors(capabs ...caps.Capability) (result map[*Session]empty) {
+	result = client.Friends(capabs...)
+	client.server.monitorManager.AddMonitors(result, client.nickCasefolded, capabs...)
+	return
+}
+
 // helper for Friends
 func addFriendsToSet(set map[*Session]empty, client *Client, capabs ...caps.Capability) {
 	client.stateMutex.RLock()
@@ -1049,7 +1056,7 @@ func (client *Client) SetOper(oper *Oper) {
 func (client *Client) sendChghost(oldNickMask string, vhost string) {
 	details := client.Details()
 	isBot := client.HasMode(modes.Bot)
-	for fClient := range client.Friends(caps.ChgHost) {
+	for fClient := range client.FriendsMonitors(caps.ChgHost) {
 		fClient.sendFromClientInternal(false, time.Time{}, "", oldNickMask, details.accountName, isBot, nil, "CHGHOST", details.username, vhost)
 	}
 }
diff --git a/irc/handlers.go b/irc/handlers.go
index b76d0e68..abbc5ef1 100644
--- a/irc/handlers.go
+++ b/irc/handlers.go
@@ -109,7 +109,7 @@ func sendSuccessfulAccountAuth(service *ircService, client *Client, rb *Response
 
 	if client.Registered() {
 		// dispatch account-notify
-		for friend := range client.Friends(caps.AccountNotify) {
+		for friend := range client.FriendsMonitors(caps.AccountNotify) {
 			if friend != rb.session {
 				friend.Send(nil, details.nickMask, "ACCOUNT", details.accountName)
 			}
@@ -369,7 +369,7 @@ func dispatchAwayNotify(client *Client, isAway bool, awayMessage string) {
 	// dispatch away-notify
 	details := client.Details()
 	isBot := client.HasMode(modes.Bot)
-	for session := range client.Friends(caps.AwayNotify) {
+	for session := range client.FriendsMonitors(caps.AwayNotify) {
 		if isAway {
 			session.sendFromClientInternal(false, time.Time{}, "", details.nickMask, details.accountName, isBot, nil, "AWAY", awayMessage)
 		} else {
@@ -2875,7 +2875,7 @@ func setnameHandler(server *Server, client *Client, msg ircmsg.Message, rb *Resp
 
 	// alert friends
 	now := time.Now().UTC()
-	friends := client.Friends(caps.SetName)
+	friends := client.FriendsMonitors(caps.SetName)
 	delete(friends, rb.session)
 	isBot := client.HasMode(modes.Bot)
 	for session := range friends {
diff --git a/irc/monitor.go b/irc/monitor.go
index aa3818b5..65abe9ad 100644
--- a/irc/monitor.go
+++ b/irc/monitor.go
@@ -6,6 +6,8 @@ package irc
 import (
 	"sync"
 
+	"github.com/ergochat/ergo/irc/caps"
+
 	"github.com/ergochat/irc-go/ircmsg"
 )
 
@@ -23,6 +25,17 @@ func (mm *MonitorManager) Initialize() {
 	mm.watchedby = make(map[string]map[*Session]empty)
 }
 
+// AddMonitors adds clients using extended-monitor monitoring `client`'s nick to the passed user set.
+func (manager *MonitorManager) AddMonitors(users map[*Session]empty, cfnick string, capabs ...caps.Capability) {
+	manager.RLock()
+	defer manager.RUnlock()
+	for session := range manager.watchedby[cfnick] {
+		if session.capabilities.Has(caps.ExtendedMonitor) && session.capabilities.HasAll(capabs...) {
+			users[session] = empty{}
+		}
+	}
+}
+
 // AlertAbout alerts everyone monitoring `client`'s nick that `client` is now {on,off}line.
 func (manager *MonitorManager) AlertAbout(nick, cfnick string, online bool) {
 	var watchers []*Session