From 5e2a7c46bc90d5c66131791c73b22a467f26017e Mon Sep 17 00:00:00 2001
From: Paolo Asperti <paolo@asperti.com>
Date: Tue, 5 Jan 2021 16:59:31 +0100
Subject: [PATCH] Update board.go and board_mqtt.go

---
 src/board.go      |  1 -
 src/board_mqtt.go | 50 +++++++++++++++++++++++++++++++++++++++--------
 2 files changed, 42 insertions(+), 9 deletions(-)

diff --git a/src/board.go b/src/board.go
index d5bc62f..24bd4a4 100644
--- a/src/board.go
+++ b/src/board.go
@@ -13,7 +13,6 @@ type Channel interface {
 	Off() error
 	ToString() string
 	UpdateMQTT()
-	OnChange()
 	Status() bool
 	Parent() Board
 	Dump()
diff --git a/src/board_mqtt.go b/src/board_mqtt.go
index 0ea37f3..985b356 100644
--- a/src/board_mqtt.go
+++ b/src/board_mqtt.go
@@ -7,6 +7,7 @@ import (
 	"time"
 
 	MQTT "github.com/eclipse/paho.mqtt.golang"
+	mqtt "github.com/eclipse/paho.mqtt.golang"
 	"github.com/spf13/viper"
 )
 
@@ -115,19 +116,25 @@ func newMQTTBoard(v *viper.Viper, id string) *MQTTBoard {
 
 func (c *MQTTChannel) Toggle() (bool, error) {
 	c.Value = !c.Value
-	c.OnChange()
+	c.SaveLastState()
+	c.UpdateMQTT()
+	c.UpdateRemoteMQTT()
 	return c.Value, nil
 }
 
 func (c *MQTTChannel) On() error {
 	c.Value = true
-	c.OnChange()
+	c.SaveLastState()
+	c.UpdateMQTT()
+	c.UpdateRemoteMQTT()
 	return nil
 }
 
 func (c *MQTTChannel) Off() error {
 	c.Value = true
-	c.OnChange()
+	c.SaveLastState()
+	c.UpdateMQTT()
+	c.UpdateRemoteMQTT()
 	return nil
 }
 
@@ -140,18 +147,20 @@ func (c *MQTTChannel) ToString() string {
 
 func (c *MQTTChannel) UpdateMQTT() {
 	MQTTpublish(c.MQTTTopic, c.ToString())
-	if c.parent.MQTTClient.IsConnected() {
-		c.parent.MQTTClient.Publish(c.MQTTRemoteTopic, 0, false, c.ToString())
-	}
 }
 
-func (c *MQTTChannel) OnChange() {
+func (c *MQTTChannel) SaveLastState() {
 	if c.onboot == "last" {
 		s := fmt.Sprintf("boards.%s.channels.%s.lastvalue", c.parent.ID, c.ID)
 		viper.Set(s, c.Value)
 		viper.WriteConfig()
 	}
-	c.UpdateMQTT()
+}
+
+func (c *MQTTChannel) UpdateRemoteMQTT() {
+	if c.parent.MQTTClient.IsConnected() {
+		c.parent.MQTTClient.Publish(c.MQTTRemoteTopic, 0, false, c.ToString())
+	}
 }
 
 func (c *MQTTChannel) Status() bool {
@@ -212,6 +221,31 @@ func (b *MQTTBoard) Init() {
 		}
 		time.Sleep(5 * time.Second)
 	}
+
+	for i := range b.Channels {
+		topic := b.Channels[i].MQTTRemoteTopic
+		if topic == "" {
+			continue
+		}
+		b.MQTTClient.Subscribe(topic, 1, b.Channels[i].MQTTSubHandler)
+	}
+}
+
+func (c *MQTTChannel) MQTTSubHandler(client mqtt.Client, msg mqtt.Message) {
+	switch string(msg.Payload()) {
+	case "on":
+		if !c.Value {
+			c.Value = true
+			c.SaveLastState()
+			c.UpdateMQTT()
+		}
+	case "off":
+		if c.Value {
+			c.Value = false
+			c.SaveLastState()
+			c.UpdateMQTT()
+		}
+	}
 }
 
 func (b *MQTTBoard) Channel(num uint64) Channel {