Fix mid-cook target temperature changes

Live-tested against a real oven and found the target-temp-while-active
path was silently broken: MC_TEMP (11005) acks "success" but the
oven's own cook plan never updates (confirmed via three independent
fetchStatus() polls over 45s). Re-issuing preheat() while active
fares worse — the oven acks "not-allowed" outright.

The only sequence that actually works, verified live: cancel() then
preheat() at the new temperature. Update the thermostat accessory to
do that, and drop the dead setTemperatureC()/MC_TEMP code path since
it doesn't do anything real.

Author: keithah

README.md

@@ -110,6 +110,8 @@ Works well:
 
 HomeKit doesn't expose an oven-timer characteristic Siri can drive, so this plugin doesn't fake voice timers, timer extension, or spoken time remaining.
 
+June's oven doesn't support changing the target temperature of a cook that's already running — confirmed by testing against a real oven, both a direct "change temp" command and simply re-issuing preheat while active are rejected or silently ignored. So "Set June to 375" while it's already heating cancels the current cook and starts a new one at 375° (a brief, sub-second interruption) rather than smoothly retargeting.
+
 ## Troubleshooting
 
 - **Pairing hangs or fails** — make sure the oven and the Homebridge host both have working internet access; pairing goes through June's cloud, not local network. Double-check the 8-digit code before it expires and try again.

src/accessories/thermostat.ts

@@ -61,7 +61,15 @@ export class JuneThermostatAccessory {
     if (!this.active) {
       return;
     }
-    const status = await this.client.setTemperatureC(value);
+    // June rejects (or silently ignores) changing an already-active cook's
+    // target temperature directly — confirmed live: re-issuing preheat()
+    // while active gets acked "not-allowed", and the old MC_TEMP primitive
+    // acks "success" without actually changing the oven's target. Cancelling
+    // first and then preheating at the new temperature is what actually
+    // works, verified by polling fetchStatus() afterward.
+    const tempF = Math.round(value * 9 / 5 + 32);
+    await this.client.cancel();
+    const status = await this.client.preheat(this.client.config.defaultMode, tempF);
     if (status !== 'success') {
       this.service.updateCharacteristic(this.platform.Characteristic.TargetTemperature, previous);
       this.platform.log.warn(`June rejected target temperature change: ${status || 'no ack'}`);

src/june-client.ts

@@ -10,7 +10,6 @@ import {
   MC_CANCEL,
   MC_KEEPALIVE,
   MC_PREHEAT,
-  MC_TEMP,
   milliCToCelsius,
   normalizeOvenConfig,
   NormalizedJuneConfig,
@@ -75,11 +74,6 @@ export class JuneClient extends EventEmitter {
     return this.sendCommand(MC_PREHEAT, { primitive_type: mode, temperature_cavity: fahrenheitToMilliC(tempF) });
   }
 
-  public async setTemperatureC(tempC: number): Promise<string | null> {
-    this.lastTargetTempC = tempC;
-    return this.sendCommand(MC_TEMP, { plan_id: 0, temperature_cavity: Math.round(tempC * 1000) });
-  }
-
   public async cancel(): Promise<string | null> {
     this.lastCancelled = true;
     return this.sendCommand(MC_CANCEL, { plan_id: 0 });