From fff6f08cb63cde691a3d5fb8f1c109cbdb470c58 Mon Sep 17 00:00:00 2001
From: Wim <wim@42.be>
Date: Fri, 30 Sep 2016 23:19:47 +0200
Subject: [PATCH] Add samechannel gateway. See #35

---
 bridge/config/config.go            | 22 +++++---
 gateway/samechannel/samechannel.go | 84 ++++++++++++++++++++++++++++++
 matterbridge.go                    | 14 +++++
 3 files changed, 113 insertions(+), 7 deletions(-)
 create mode 100644 gateway/samechannel/samechannel.go

diff --git a/bridge/config/config.go b/bridge/config/config.go
index 290108af..7d4b0cd1 100644
--- a/bridge/config/config.go
+++ b/bridge/config/config.go
@@ -56,14 +56,22 @@ type Gateway struct {
 	Out    []Bridge
 }
 
+type SameChannelGateway struct {
+	Name     string
+	Enable   bool
+	Channels []string
+	Accounts []string
+}
+
 type Config struct {
-	IRC        map[string]Protocol
-	Mattermost map[string]Protocol
-	Slack      map[string]Protocol
-	Gitter     map[string]Protocol
-	Xmpp       map[string]Protocol
-	Discord    map[string]Protocol
-	Gateway    []Gateway
+	IRC                map[string]Protocol
+	Mattermost         map[string]Protocol
+	Slack              map[string]Protocol
+	Gitter             map[string]Protocol
+	Xmpp               map[string]Protocol
+	Discord            map[string]Protocol
+	Gateway            []Gateway
+	SameChannelGateway []SameChannelGateway
 }
 
 func NewConfig(cfgfile string) *Config {
diff --git a/gateway/samechannel/samechannel.go b/gateway/samechannel/samechannel.go
new file mode 100644
index 00000000..1ed43750
--- /dev/null
+++ b/gateway/samechannel/samechannel.go
@@ -0,0 +1,84 @@
+package samechannelgateway
+
+import (
+	"github.com/42wim/matterbridge/bridge"
+	"github.com/42wim/matterbridge/bridge/config"
+	log "github.com/Sirupsen/logrus"
+	"strings"
+)
+
+type SameChannelGateway struct {
+	*config.Config
+	MyConfig    *config.SameChannelGateway
+	Bridges     []bridge.Bridge
+	Channels    []string
+	ignoreNicks map[string][]string
+	Name        string
+}
+
+func New(cfg *config.Config, gateway *config.SameChannelGateway) error {
+	c := make(chan config.Message)
+	gw := &SameChannelGateway{}
+	gw.Name = gateway.Name
+	gw.Config = cfg
+	gw.MyConfig = gateway
+	gw.Channels = gateway.Channels
+	for _, account := range gateway.Accounts {
+		br := config.Bridge{Account: account}
+		log.Infof("Starting bridge: %s", account)
+		gw.Bridges = append(gw.Bridges, bridge.New(cfg, &br, c))
+	}
+	for _, br := range gw.Bridges {
+		br.Connect()
+		for _, channel := range gw.Channels {
+			log.Infof("%s: joining %s", br.FullOrigin(), channel)
+			br.JoinChannel(channel)
+		}
+	}
+	gw.handleReceive(c)
+	return nil
+}
+
+func (gw *SameChannelGateway) handleReceive(c chan config.Message) {
+	for {
+		select {
+		case msg := <-c:
+			for _, br := range gw.Bridges {
+				gw.handleMessage(msg, br)
+			}
+		}
+	}
+}
+
+func (gw *SameChannelGateway) handleMessage(msg config.Message, dest bridge.Bridge) {
+	// do not send the message to the bridge we come from if also the channel is the same
+	if msg.FullOrigin == dest.FullOrigin() {
+		return
+	}
+	gw.modifyMessage(&msg, dest)
+	log.Debugf("Sending %#v from %s to %s", msg, msg.FullOrigin, dest.FullOrigin())
+	dest.Send(msg)
+}
+
+func setNickFormat(msg *config.Message, format string) {
+	if format == "" {
+		msg.Username = msg.Protocol + "." + msg.Origin + "-" + msg.Username + ": "
+		return
+	}
+	msg.Username = strings.Replace(format, "{NICK}", msg.Username, -1)
+	msg.Username = strings.Replace(msg.Username, "{BRIDGE}", msg.Origin, -1)
+	msg.Username = strings.Replace(msg.Username, "{PROTOCOL}", msg.Protocol, -1)
+}
+
+func (gw *SameChannelGateway) modifyMessage(msg *config.Message, dest bridge.Bridge) {
+	switch dest.Protocol() {
+	case "irc":
+		setNickFormat(msg, gw.Config.IRC[dest.Origin()].RemoteNickFormat)
+	case "mattermost":
+		setNickFormat(msg, gw.Config.Mattermost[dest.Origin()].RemoteNickFormat)
+	case "slack":
+		setNickFormat(msg, gw.Config.Slack[dest.Origin()].RemoteNickFormat)
+	case "discord":
+		setNickFormat(msg, gw.Config.Discord[dest.Origin()].RemoteNickFormat)
+	}
+}
diff --git a/matterbridge.go b/matterbridge.go
index 470c6056..28a76fa1 100644
--- a/matterbridge.go
+++ b/matterbridge.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"github.com/42wim/matterbridge/bridge/config"
 	"github.com/42wim/matterbridge/gateway"
+	"github.com/42wim/matterbridge/gateway/samechannel"
 	log "github.com/Sirupsen/logrus"
 )
 
@@ -30,6 +31,19 @@ func main() {
 	}
 	fmt.Println("running version", version)
 	cfg := config.NewConfig(*flagConfig)
+	for _, gw := range cfg.SameChannelGateway {
+		if !gw.Enable {
+			continue
+		}
+		fmt.Printf("starting samechannel gateway %#v\n", gw.Name)
+		go func(gw config.SameChannelGateway) {
+			err := samechannelgateway.New(cfg, &gw)
+			if err != nil {
+				log.Debugf("starting gateway failed %#v", err)
+			}
+		}(gw)
+	}
+
 	for _, gw := range cfg.Gateway {
 		if !gw.Enable {
 			continue