Add initial support for getting ChannelMember info of all bridges (#678)

* Add initial support for getting ChannelMember info of all bridges.

Adds an EventGetChannelMembers event, which gets send every x time to
all bridges. Bridges should respond on this event with a Message
containing ChannelMembers in the EventGetChannelMembers key in the
Extra field.

handleEventGetChannelMembers will handle this Message and sets the
contained ChannelMembers to the Bridge struct.

* Add ChannelMembers support to the slack bridge

7 files changed, 189 insertions, 21 deletions

diff --git a/bridge/bridge.go b/bridge/bridge.go
index 336e2e2c..6b955a9e 100644
--- a/bridge/bridge.go
+++ b/bridge/bridge.go
@@ -5,6 +5,7 @@ import (
 
 	"github.com/42wim/matterbridge/bridge/config"
 	"github.com/sirupsen/logrus"
+	"sync"
 )
 
 type Bridger interface {
@@ -16,14 +17,16 @@ type Bridger interface {
 
 type Bridge struct {
 	Bridger
-	Name     string
-	Account  string
-	Protocol string
-	Channels map[string]config.ChannelInfo
-	Joined   map[string]bool
-	Log      *logrus.Entry
-	Config   config.Config
-	General  *config.Protocol
+	Name           string
+	Account        string
+	Protocol       string
+	Channels       map[string]config.ChannelInfo
+	Joined         map[string]bool
+	ChannelMembers *config.ChannelMembers
+	Log            *logrus.Entry
+	Config         config.Config
+	General        *config.Protocol
+	*sync.RWMutex
 }
 
 type Config struct {
@@ -37,15 +40,17 @@ type Config struct {
 type Factory func(*Config) Bridger
 
 func New(bridge *config.Bridge) *Bridge {
-	b := new(Bridge)
-	b.Channels = make(map[string]config.ChannelInfo)
+	b := &Bridge{
+		Channels: make(map[string]config.ChannelInfo),
+		RWMutex:  new(sync.RWMutex),
+		Joined:   make(map[string]bool),
+	}
 	accInfo := strings.Split(bridge.Account, ".")
 	protocol := accInfo[0]
 	name := accInfo[1]
 	b.Name = name
 	b.Protocol = protocol
 	b.Account = bridge.Account
-	b.Joined = make(map[string]bool)
 	return b
 }
 
@@ -54,6 +59,13 @@ func (b *Bridge) JoinChannels() error {
 	return err
 }
 
+// SetChannelMembers sets the newMembers to the bridge ChannelMembers
+func (b *Bridge) SetChannelMembers(newMembers *config.ChannelMembers) {
+	b.Lock()
+	b.ChannelMembers = newMembers
+	b.Unlock()
+}
+
 func (b *Bridge) joinChannels(channels map[string]config.ChannelInfo, exists map[string]bool) error {
 	for ID, channel := range channels {
 		if !exists[ID] {
diff --git a/bridge/config/config.go b/bridge/config/config.go
index 932de2eb..3d1206c7 100644
--- a/bridge/config/config.go
+++ b/bridge/config/config.go
@@ -14,16 +14,17 @@ import (
 )
 
 const (
-	EventJoinLeave       = "join_leave"
-	EventTopicChange     = "topic_change"
-	EventFailure         = "failure"
-	EventFileFailureSize = "file_failure_size"
-	EventAvatarDownload  = "avatar_download"
-	EventRejoinChannels  = "rejoin_channels"
-	EventUserAction      = "user_action"
-	EventMsgDelete       = "msg_delete"
-	EventAPIConnected    = "api_connected"
-	EventUserTyping      = "user_typing"
+	EventJoinLeave         = "join_leave"
+	EventTopicChange       = "topic_change"
+	EventFailure           = "failure"
+	EventFileFailureSize   = "file_failure_size"
+	EventAvatarDownload    = "avatar_download"
+	EventRejoinChannels    = "rejoin_channels"
+	EventUserAction        = "user_action"
+	EventMsgDelete         = "msg_delete"
+	EventAPIConnected      = "api_connected"
+	EventUserTyping        = "user_typing"
+	EventGetChannelMembers = "get_channel_members"
 )
 
 type Message struct {
@@ -61,6 +62,16 @@ type ChannelInfo struct {
 	Options     ChannelOptions
 }
 
+type ChannelMember struct {
+	Username    string
+	Nick        string
+	UserID      string
+	ChannelID   string
+	ChannelName string
+}
+
+type ChannelMembers []ChannelMember
+
 type Protocol struct {
 	AuthCode               string // steam
 	BindAddress            string // mattermost, slack // DEPRECATED
diff --git a/bridge/slack/handlers.go b/bridge/slack/handlers.go
index f46eb595..5e601eaa 100644
--- a/bridge/slack/handlers.go
+++ b/bridge/slack/handlers.go
@@ -309,6 +309,58 @@ func (b *Bslack) handleDownloadFile(rmsg *config.Message, file *slack.File, retr
 	return nil
 }
 
+// handleGetChannelMembers handles messages containing the GetChannelMembers event
+// Sends a message to the router containing *config.ChannelMembers
+func (b *Bslack) handleGetChannelMembers(rmsg *config.Message) bool {
+	if rmsg.Event != config.EventGetChannelMembers {
+		return false
+	}
+
+	cMembers := config.ChannelMembers{}
+
+	b.channelMembersMutex.RLock()
+
+	for channelID, members := range b.channelMembers {
+		for _, member := range members {
+			channelName := ""
+			userName := ""
+			userNick := ""
+			user := b.getUser(member)
+			if user != nil {
+				userName = user.Name
+				userNick = user.Profile.DisplayName
+			}
+			channel, _ := b.getChannelByID(channelID)
+			if channel != nil {
+				channelName = channel.Name
+			}
+			cMember := config.ChannelMember{
+				Username:    userName,
+				Nick:        userNick,
+				UserID:      member,
+				ChannelID:   channelID,
+				ChannelName: channelName,
+			}
+			cMembers = append(cMembers, cMember)
+		}
+	}
+
+	b.channelMembersMutex.RUnlock()
+
+	extra := make(map[string][]interface{})
+	extra[config.EventGetChannelMembers] = append(extra[config.EventGetChannelMembers], cMembers)
+	msg := config.Message{
+		Extra:   extra,
+		Event:   config.EventGetChannelMembers,
+		Account: b.Account,
+	}
+
+	b.Log.Debugf("sending msg to remote %#v", msg)
+	b.Remote <- msg
+
+	return true
+}
+
 // fileCached implements Matterbridge's caching logic for files
 // shared via Slack.
 //
diff --git a/bridge/slack/helpers.go b/bridge/slack/helpers.go
index 4e6e5652..d84353f0 100644
--- a/bridge/slack/helpers.go
+++ b/bridge/slack/helpers.go
@@ -93,7 +93,9 @@ func (b *Bslack) populateUsers(wait bool) {
 		return
 	}
 	for b.refreshInProgress {
+		b.refreshMutex.Unlock()
 		time.Sleep(time.Second)
+		b.refreshMutex.Lock()
 	}
 	b.refreshInProgress = true
 	b.refreshMutex.Unlock()
@@ -139,13 +141,16 @@ func (b *Bslack) populateChannels(wait bool) {
 		return
 	}
 	for b.refreshInProgress {
+		b.refreshMutex.Unlock()
 		time.Sleep(time.Second)
+		b.refreshMutex.Lock()
 	}
 	b.refreshInProgress = true
 	b.refreshMutex.Unlock()
 
 	newChannelsByID := map[string]*slack.Channel{}
 	newChannelsByName := map[string]*slack.Channel{}
+	newChannelMembers := make(map[string][]string)
 
 	// We only retrieve public and private channels, not IMs
 	// and MPIMs as those do not have a channel name.
@@ -166,7 +171,18 @@ func (b *Bslack) populateChannels(wait bool) {
 		for i := range channels {
 			newChannelsByID[channels[i].ID] = &channels[i]
 			newChannelsByName[channels[i].Name] = &channels[i]
+			// also find all the members in every channel
+			members, err := b.getUsersInConversation(channels[i].ID)
+			if err != nil {
+				if err = b.handleRateLimit(err); err != nil {
+					b.Log.Errorf("Could not retrieve channel members: %#v", err)
+					return
+				}
+				continue
+			}
+			newChannelMembers[channels[i].ID] = members
 		}
+
 		if nextCursor == "" {
 			break
 		}
@@ -178,6 +194,10 @@ func (b *Bslack) populateChannels(wait bool) {
 	b.channelsByID = newChannelsByID
 	b.channelsByName = newChannelsByName
 
+	b.channelMembersMutex.Lock()
+	defer b.channelMembersMutex.Unlock()
+	b.channelMembers = newChannelMembers
+
 	b.refreshMutex.Lock()
 	defer b.refreshMutex.Unlock()
 	b.earliestChannelRefresh = time.Now().Add(minimumRefreshInterval)
@@ -367,3 +387,29 @@ func (b *Bslack) handleRateLimit(err error) error {
 	time.Sleep(rateLimit.RetryAfter)
 	return nil
 }
+
+// getUsersInConversation returns an array of userIDs that are members of channelID
+func (b *Bslack) getUsersInConversation(channelID string) ([]string, error) {
+	channelMembers := []string{}
+	for {
+		queryParams := &slack.GetUsersInConversationParameters{
+			ChannelID: channelID,
+		}
+
+		members, nextCursor, err := b.sc.GetUsersInConversation(queryParams)
+		if err != nil {
+			if err = b.handleRateLimit(err); err != nil {
+				return channelMembers, fmt.Errorf("Could not retrieve users in channels: %#v", err)
+			}
+			continue
+		}
+
+		channelMembers = append(channelMembers, members...)
+
+		if nextCursor == "" {
+			break
+		}
+		queryParams.Cursor = nextCursor
+	}
+	return channelMembers, nil
+}
diff --git a/bridge/slack/slack.go b/bridge/slack/slack.go
index b9430278..001b1268 100644
--- a/bridge/slack/slack.go
+++ b/bridge/slack/slack.go
@@ -37,6 +37,9 @@ type Bslack struct {
 	channelsByName map[string]*slack.Channel
 	channelsMutex  sync.RWMutex
 
+	channelMembers      map[string][]string
+	channelMembersMutex sync.RWMutex
+
 	refreshInProgress      bool
 	earliestChannelRefresh time.Time
 	earliestUserRefresh    time.Time
@@ -267,6 +270,11 @@ func (b *Bslack) sendWebhook(msg config.Message) error {
 }
 
 func (b *Bslack) sendRTM(msg config.Message) (string, error) {
+	// Handle channelmember messages.
+	if handled := b.handleGetChannelMembers(&msg); handled {
+		return "", nil
+	}
+
 	channelInfo, err := b.getChannel(msg.Channel)
 	if err != nil {
 		return "", fmt.Errorf("could not send message: %v", err)
diff --git a/gateway/handlers.go b/gateway/handlers.go
index 741c312e..5af13c14 100644
--- a/gateway/handlers.go
+++ b/gateway/handlers.go
@@ -30,6 +30,23 @@ func (r *Router) handleEventFailure(msg *config.Message) {
 	}
 }
 
+// handleEventGetChannelMembers handles channel members
+func (r *Router) handleEventGetChannelMembers(msg *config.Message) {
+	if msg.Event != config.EventGetChannelMembers {
+		return
+	}
+	for _, gw := range r.Gateways {
+		for _, br := range gw.Bridges {
+			if msg.Account == br.Account {
+				cMembers := msg.Extra[config.EventGetChannelMembers][0].(config.ChannelMembers)
+				flog.Debugf("Syncing channelmembers from %s", msg.Account)
+				br.SetChannelMembers(&cMembers)
+				return
+			}
+		}
+	}
+}
+
 // handleEventRejoinChannels handles rejoining of channels.
 func (r *Router) handleEventRejoinChannels(msg *config.Message) {
 	if msg.Event != config.EventRejoinChannels {
diff --git a/gateway/router.go b/gateway/router.go
index a7181b96..d3c33b2a 100644
--- a/gateway/router.go
+++ b/gateway/router.go
@@ -2,6 +2,7 @@ package gateway
 
 import (
 	"fmt"
+	"sync"
 	"time"
 
 	"github.com/42wim/matterbridge/bridge"
@@ -16,6 +17,7 @@ type Router struct {
 	Gateways         map[string]*Gateway
 	Message          chan config.Message
 	MattermostPlugin chan config.Message
+	sync.RWMutex
 }
 
 func NewRouter(cfg config.Config, bridgeMap map[string]bridge.Factory) (*Router, error) {
@@ -81,6 +83,7 @@ func (r *Router) Start() error {
 		}
 	}
 	go r.handleReceive()
+	go r.updateChannelMembers()
 	return nil
 }
 
@@ -108,6 +111,7 @@ func (r *Router) getBridge(account string) *bridge.Bridge {
 func (r *Router) handleReceive() {
 	for msg := range r.Message {
 		msg := msg // scopelint
+		r.handleEventGetChannelMembers(&msg)
 		r.handleEventFailure(&msg)
 		r.handleEventRejoinChannels(&msg)
 		for _, gw := range r.Gateways {
@@ -129,3 +133,21 @@ func (r *Router) handleReceive() {
 		}
 	}
 }
+
+// updateChannelMembers sends every minute an GetChannelMembers event to all bridges.
+func (r *Router) updateChannelMembers() {
+	// TODO sleep a minute because slack can take a while
+	// fix this by having actually connectionDone events send to the router
+	time.Sleep(time.Minute)
+	for {
+		for _, gw := range r.Gateways {
+			for _, br := range gw.Bridges {
+				flog.Debugf("sending %s to %s", config.EventGetChannelMembers, br.Account)
+				if _, err := br.Send(config.Message{Event: config.EventGetChannelMembers}); err != nil {
+					flog.Errorf("updateChannelMembers: %s", err)
+				}
+			}
+		}
+		time.Sleep(time.Minute)
+	}
+}