feat!: add airing, and deliver commands by comparing desired and reported state

README.md

@@ -4,11 +4,20 @@ A small web page to adjust the heating per room from a phone on the home network
 
 <img src="docs/screenshot.png" alt="The heating page on a phone: Office and Bedroom cards, each with the room temperature, whether it is heating, the target and buttons to change it" width="360">
 
-Work in progress.
+## Airing
+
+"Airing 15/30/60" sends `system_mode: off`. When the time is up, or on "Heat again", the room gets back the mode and target from before.
+
+The service keeps no saved state, so a restart during airing forgets it: **that room stays off until someone taps "Heat again"**. A target waiting to be sent is lost too. The thermostat's own frost protection still applies.
+
+- A target changed during airing is applied when it ends.
+- A thermostat leaving off during airing gets off once more. If it leaves off again, someone is at the radiator, so airing ends.
+- Commands repeat until the thermostat confirms them, every 30 s for about 5 minutes. A target then gives up and shows the thermostat's value. Off and heat-again keep trying every 5 minutes and show a problem on the page, because giving up would mean heating with the window open or a cold room.
+- A thermostat that is off with no airing is left alone, because it can turn itself off and come back. The page offers "Heat again" for it.
 
 ## Deployment
 
-The Helm chart in [`charts/heating-control`](charts/heating-control) is published with every release as `oci://ghcr.io/subpathdev/charts/heating-control`. Set `config.broker` and `config.rooms`; adding a room is one more entry in `config.rooms`. Run one replica only, because the MQTT client ID is fixed.
+The Helm chart in [`charts/heating-control`](charts/heating-control) is published with every release as `oci://ghcr.io/subpathdev/charts/heating-control`. Set `config.broker` and `config.rooms`; adding a room is one more entry in `config.rooms`. Run one replica only, and give any other instance its own `config.clientId`: a second client with the same ID disconnects the first.
 
 ## API
 

cmd/heating-control/main.go

@@ -49,13 +49,19 @@ func main() {
 	health.Register(mux, version, checker)
 	mux.Handle("GET /metrics", m.Handler())
 	// Probes and scrapes use the pod's IP and stay outside the page's checks.
-	mux.Handle("/", web.Handler(ctrl, cfg.AllowedHosts))
+	mux.Handle("/", web.Handler(ctrl, checker, cfg.AllowedHosts))
 
 	srv := &http.Server{
 		Addr:              ":8080",
 		Handler:           mux,
 		ReadHeaderTimeout: 5 * time.Second,
 	}
+	controllerDone := make(chan struct{})
+	go func() {
+		defer close(controllerDone)
+		ctrl.Run(ctx)
+	}()
+
 	shutdownDone := make(chan struct{})
 	go func() {
 		defer close(shutdownDone)
@@ -73,5 +79,5 @@ func main() {
 	}
 	// ListenAndServe returns as soon as Shutdown starts, so let requests finish.
 	<-shutdownDone
-	ctrl.Wait()
+	<-controllerDone
 }