MONITOR user with whom we have an open buffer

7 files changed, 145 insertions, 16 deletions

diff --git a/app.go b/app.go
index 1144560..85836e8 100644
--- a/app.go
+++ b/app.go
@@ -95,6 +95,8 @@ type App struct {
 	lastNetID     string
 	lastBuffer    string
 
+	monitor map[string]map[string]struct{} // set of targets we want to monitor per netID, best-effort. netID->target->{}
+
 	lastMessageTime time.Time
 	lastCloseTime   time.Time
 }
@@ -105,6 +107,7 @@ func NewApp(cfg Config) (app *App, err error) {
 		events:        make(chan event, eventChanSize),
 		cfg:           cfg,
 		messageBounds: map[boundKey]bound{},
+		monitor:       make(map[string]map[string]struct{}),
 	}
 
 	if cfg.Highlights != nil {
@@ -582,6 +585,9 @@ func (app *App) handleIRCEvent(netID string, ev interface{}) {
 			s.Close()
 		}
 		app.sessions[netID] = s
+		if _, ok := app.monitor[netID]; !ok {
+			app.monitor[netID] = make(map[string]struct{})
+		}
 		return
 	}
 	if _, ok := ev.(irc.Typing); ok {
@@ -633,6 +639,10 @@ func (app *App) handleIRCEvent(netID string, ev interface{}) {
 			Head: "--",
 			Body: ui.PlainString(body),
 		})
+		for target := range app.monitor[s.NetID()] {
+			// TODO: batch MONITOR +
+			s.MonitorAdd(target)
+		}
 	case irc.SelfNickEvent:
 		var body ui.StyledStringBuilder
 		body.WriteString(fmt.Sprintf("%s\u2192%s", ev.FormerNick, s.Nick()))
@@ -729,6 +739,8 @@ func (app *App) handleIRCEvent(netID string, ev interface{}) {
 		buffer, line, notification := app.formatMessage(s, ev)
 		if buffer != "" && !s.IsChannel(buffer) {
 			if _, added := app.win.AddBuffer(netID, "", buffer); added {
+				app.monitor[netID][buffer] = struct{}{}
+				s.MonitorAdd(buffer)
 				s.NewHistoryRequest(buffer).
 					WithLimit(500).
 					Before(msg.TimeOrNow())
@@ -750,6 +762,7 @@ func (app *App) handleIRCEvent(netID string, ev interface{}) {
 			if s.IsChannel(target) {
 				continue
 			}
+			s.MonitorAdd(target)
 			app.win.AddBuffer(netID, "", target)
 			// CHATHISTORY BEFORE excludes its bound, so add 1ms
 			// (precision of the time tag) to include that last message.
diff --git a/commands.go b/commands.go
index 403aec8..09582b6 100644
--- a/commands.go
+++ b/commands.go
@@ -341,6 +341,8 @@ func commandDoMsg(app *App, args []string) (err error) {
 			Time:            time.Now(),
 		})
 		if buffer != "" && !s.IsChannel(target) {
+			app.monitor[netID][buffer] = struct{}{}
+			s.MonitorAdd(buffer)
 			app.win.AddBuffer(netID, "", buffer)
 		}
 
@@ -449,6 +451,7 @@ func commandDoQuery(app *App, args []string) (err error) {
 	if s.IsChannel(target) {
 		return fmt.Errorf("cannot query a channel, use JOIN instead")
 	}
+	s.MonitorAdd(target)
 	i, _ := app.win.AddBuffer(netID, "", target)
 	s.NewHistoryRequest(target).WithLimit(200).Before(time.Now())
 	app.win.JumpBufferIndex(i)
diff --git a/irc/events.go b/irc/events.go
index 0c84f2b..f8f002f 100644
--- a/irc/events.go
+++ b/irc/events.go
@@ -50,6 +50,14 @@ type UserQuitEvent struct {
 	Time     time.Time
 }
 
+type UserOnlineEvent struct {
+	User string
+}
+
+type UserOfflineEvent struct {
+	User string
+}
+
 type TopicChangeEvent struct {
 	Channel string
 	Topic   string
diff --git a/irc/rpl.go b/irc/rpl.go
index 6373972..398b5b3 100644
--- a/irc/rpl.go
+++ b/irc/rpl.go
@@ -87,6 +87,12 @@ const (
 	errUmodeunknownflag = "501" // :Unknown mode flag
 	errUsersdontmatch   = "502" // :Can't change mode for other users
 
+	rplMononline     = "730" // <nick> :target[!user@host][,target[!user@host]]*
+	rplMonoffline    = "731" // <nick> :target[,target2]*
+	rplMonlist       = "732" // <nick> :target[,target2]*
+	rplEndofmonlist  = "733" // <nick> :End of MONITOR list
+	errMonlistisfull = "734" // <nick> <limit> <targets> :Monitor list is full.
+
 	rplLoggedin    = "900" // <nick> <nick>!<ident>@<host> <account> :You are now logged in as <user>
 	rplLoggedout   = "901" // <nick> <nick>!<ident>@<host> :You are now logged out
 	errNicklocked  = "902" // :You must use a nick assigned to you
diff --git a/irc/session.go b/irc/session.go
index 3dd979c..96632bf 100644
--- a/irc/session.go
+++ b/irc/session.go
@@ -71,10 +71,11 @@ const (
 	TypingDone
 )
 
-// User is a known IRC user (we share a channel with it).
+// User is a known IRC user.
 type User struct {
-	Name *Prefix // the nick, user and hostname of the user if known.
-	Away bool    // whether the user is away or not
+	Name         *Prefix // the nick, user and hostname of the user if known.
+	Away         bool    // whether the user is away or not
+	Disconnected bool    // can only be true for monitored users.
 }
 
 // Channel is a joined channel.
@@ -124,6 +125,7 @@ type Session struct {
 	historyLimit  int
 	prefixSymbols string
 	prefixModes   string
+	monitor       bool
 
 	users          map[string]*User        // known users.
 	channels       map[string]Channel      // joined channels.
@@ -131,6 +133,7 @@ type Session struct {
 	chReqs         map[string]struct{}     // set of targets for which history is currently requested.
 	targetsBatchID string                  // ID of the channel history targets batch being processed.
 	targetsBatch   HistoryTargetsEvent     // channel history targets batch being processed.
+	monitors       map[string]struct{}     // set of users we want to monitor (and keep even if they are disconnected).
 
 	pendingChannels map[string]time.Time // set of join requests stamps for channels.
 }
@@ -158,6 +161,7 @@ func NewSession(out chan<- Message, params SessionParams) *Session {
 		channels:        map[string]Channel{},
 		chBatches:       map[string]HistoryEvent{},
 		chReqs:          map[string]struct{}{},
+		monitors:        map[string]struct{}{},
 		pendingChannels: map[string]time.Time{},
 	}
 
@@ -235,16 +239,18 @@ func (s *Session) Names(target string) []Member {
 			names = make([]Member, 0, len(c.Members))
 			for u, pl := range c.Members {
 				names = append(names, Member{
-					PowerLevel: pl,
-					Name:       u.Name.Copy(),
-					Away:       u.Away,
+					PowerLevel:   pl,
+					Name:         u.Name.Copy(),
+					Away:         u.Away,
+					Disconnected: u.Disconnected,
 				})
 			}
 		}
 	} else if u, ok := s.users[s.Casemap(target)]; ok {
 		names = append(names, Member{
-			Name: u.Name.Copy(),
-			Away: u.Away,
+			Name:         u.Name.Copy(),
+			Away:         u.Away,
+			Disconnected: u.Disconnected,
 		})
 		names = append(names, Member{
 			Name: &Prefix{
@@ -278,7 +284,7 @@ func (s *Session) TypingStops() <-chan Typing {
 
 func (s *Session) ChannelsSharedWith(name string) []string {
 	var user *User
-	if u, ok := s.users[s.Casemap(name)]; ok {
+	if u, ok := s.users[s.Casemap(name)]; ok && !u.Disconnected {
 		user = u
 	} else {
 		return nil
@@ -420,6 +426,26 @@ func (s *Session) TypingStop(target string) {
 	s.out <- NewMessage("TAGMSG", target).WithTag("+typing", "done")
 }
 
+func (s *Session) MonitorAdd(target string) {
+	targetCf := s.casemap(target)
+	if _, ok := s.monitors[targetCf]; !ok {
+		s.monitors[targetCf] = struct{}{}
+		if s.monitor {
+			s.out <- NewMessage("MONITOR", "+", target)
+		}
+	}
+}
+
+func (s *Session) MonitorRemove(target string) {
+	targetCf := s.casemap(target)
+	if _, ok := s.monitors[targetCf]; ok {
+		delete(s.monitors, targetCf)
+		if s.monitor {
+			s.out <- NewMessage("MONITOR", "-", target)
+		}
+	}
+}
+
 type HistoryRequest struct {
 	s       *Session
 	target  string
@@ -603,12 +629,12 @@ func (s *Session) handleMessageRegistered(msg Message, playback bool) (Event, er
 		if s.host == "" {
 			s.out <- NewMessage("WHO", s.nick)
 		}
-		return RegisteredEvent{}, nil
 	case rplIsupport:
 		if len(msg.Params) < 3 {
 			return nil, msg.errNotEnoughParams(3)
 		}
 		s.updateFeatures(msg.Params[1 : len(msg.Params)-1])
+		return RegisteredEvent{}, nil
 	case rplWhoreply:
 		var nick, host, flags, username string
 		if err := msg.ParseParams(nil, nil, &username, &host, nil, &nick, &flags, nil); err != nil {
@@ -812,6 +838,7 @@ func (s *Session) handleMessageRegistered(msg Message, playback bool) (Event, er
 		nickCf := s.Casemap(msg.Prefix.Name)
 
 		if u, ok := s.users[nickCf]; ok {
+			u.Disconnected = true
 			var channels []string
 			for channelCf, c := range s.channels {
 				if _, ok := c.Members[u]; ok {
@@ -827,6 +854,54 @@ func (s *Session) handleMessageRegistered(msg Message, playback bool) (Event, er
 				Time:     msg.TimeOrNow(),
 			}, nil
 		}
+	case rplMononline:
+		for _, target := range strings.Split(msg.Params[1], ",") {
+			prefix := ParsePrefix(target)
+			if prefix == nil {
+				continue
+			}
+			nickCf := s.casemap(prefix.Name)
+
+			if _, ok := s.monitors[nickCf]; ok {
+				u, ok := s.users[nickCf]
+				if !ok {
+					u = &User{
+						Name: prefix,
+					}
+					s.users[nickCf] = u
+				}
+				if u.Disconnected {
+					u.Disconnected = false
+					return UserOnlineEvent{
+						User: u.Name.Name,
+					}, nil
+				}
+			}
+		}
+	case rplMonoffline:
+		for _, target := range strings.Split(msg.Params[1], ",") {
+			prefix := ParsePrefix(target)
+			if prefix == nil {
+				continue
+			}
+			nickCf := s.casemap(prefix.Name)
+
+			if _, ok := s.monitors[nickCf]; ok {
+				u, ok := s.users[nickCf]
+				if !ok {
+					u = &User{
+						Name: prefix,
+					}
+					s.users[nickCf] = u
+				}
+				if !u.Disconnected {
+					u.Disconnected = true
+					return UserOfflineEvent{
+						User: u.Name.Name,
+					}, nil
+				}
+			}
+		}
 	case rplNamreply:
 		var channel, names string
 		if err := msg.ParseParams(nil, nil, &channel, &names); err != nil {
@@ -1205,6 +1280,8 @@ func (s *Session) handleMessageRegistered(msg Message, playback bool) (Event, er
 			Code:     code,
 			Message:  strings.Join(msg.Params[2:], " "),
 		}, nil
+	case errMonlistisfull:
+		// silence monlist full error, we don't care because we do it best-effort
 	default:
 		if msg.IsReply() {
 			if len(msg.Params) < 2 {
@@ -1248,12 +1325,16 @@ func (s *Session) newMessageEvent(msg Message) (ev MessageEvent, err error) {
 }
 
 func (s *Session) cleanUser(parted *User) {
+	nameCf := s.Casemap(parted.Name.Name)
+	if _, ok := s.monitors[nameCf]; ok {
+		return
+	}
 	for _, c := range s.channels {
 		if _, ok := c.Members[parted]; ok {
 			return
 		}
 	}
-	delete(s.users, s.Casemap(parted.Name.Name))
+	delete(s.users, nameCf)
 }
 
 func (s *Session) updateFeatures(features []string) {
@@ -1315,6 +1396,11 @@ func (s *Session) updateFeatures(features []string) {
 			if err == nil && linelen != 0 {
 				s.linelen = linelen
 			}
+		case "MONITOR":
+			monitor, err := strconv.Atoi(value)
+			if err == nil && monitor > 0 {
+				s.monitor = true
+			}
 		case "PREFIX":
 			if value == "" {
 				s.prefixModes = ""
diff --git a/irc/tokens.go b/irc/tokens.go
index ab7b418..aaffc08 100644
--- a/irc/tokens.go
+++ b/irc/tokens.go
@@ -460,9 +460,10 @@ func ParseCaps(caps string) (diff []Cap) {
 
 // Member is a token in RPL_NAMREPLY's last parameter.
 type Member struct {
-	PowerLevel string
-	Name       *Prefix
-	Away       bool
+	PowerLevel   string
+	Name         *Prefix
+	Away         bool
+	Disconnected bool
 }
 
 type members []Member
diff --git a/ui/ui.go b/ui/ui.go
index 7e02812..750644c 100644
--- a/ui/ui.go
+++ b/ui/ui.go
@@ -403,15 +403,27 @@ func drawVerticalMemberList(screen tcell.Screen, x0, y0, width, height int, memb
 	width--
 	clearArea(screen, x0, y0, width, height)
 
+	padding := 1
+	for _, m := range members {
+		if m.Disconnected {
+			padding = runeWidth(0x274C)
+			break
+		}
+	}
+
 	for i, m := range members[*offset:] {
 		x := x0
 		y := y0 + i
-		if m.PowerLevel != "" {
+		if m.Disconnected {
+			disconnectedSt := tcell.StyleDefault.Foreground(tcell.ColorRed)
+			printString(screen, &x, y, Styled("\u274C", disconnectedSt))
+		} else if m.PowerLevel != "" {
+			x += padding - 1
 			powerLevelText := m.PowerLevel[:1]
 			powerLevelSt := tcell.StyleDefault.Foreground(tcell.ColorGreen)
 			printString(screen, &x, y, Styled(powerLevelText, powerLevelSt))
 		} else {
-			x++
+			x += padding
 		}
 
 		var name StyledString