Separate MQTT logic

This reduces the coupling between the MQTT-related code and everything
else to a single `tx` channel of type `MQTTMessage`.

This improves the code quality significantly.

1 files changed, 7 insertions, 6 deletions

diff --git a/cache.go b/cache.go
index 31c8ba5..e5a4e4f 100644
--- a/cache.go
+++ b/cache.go
@@ -3,21 +3,19 @@ package main
 import (
 	"fmt"
 	"log"
-
-	mqtt "github.com/eclipse/paho.mqtt.golang"
 )
 
 type States map[string]bool
 
 type Cache struct {
-	Client mqtt.Client
+	Tx     chan MQTTMessage
 	States map[string]bool
 }
 
-func NewCache(client mqtt.Client) Cache {
+func NewCache(tx chan MQTTMessage) Cache {
 	var cache Cache
 
-	cache.Client = client
+	cache.Tx     = tx
 	cache.States = make(States)
 
 	return cache
@@ -42,7 +40,10 @@ func (c *Cache) Update(states States) {
 			} else {
 				payload = []byte("closed")
 			}
-			_ = c.Client.Publish(topic, QOS, RETAINED, payload)
+			c.Tx <- MQTTMessage{
+				Topic: topic,
+				Payload: payload,
+			}
 		}
 		c.States[id] = state
 	}