add set mode option

proto/econet/v1alpha1/econet.proto

@@ -30,6 +30,22 @@ message Device {
   google.protobuf.Timestamp last_updated = 18;
 }
 
+// Mode is a settable operating mode for a water heater. The values mirror the
+// kebab-case slugs reported in Device.mode. Not every device supports every
+// mode; the supported set is device-specific (derived from the unit's reported
+// mode list), so SetMode validates against the target device.
+enum Mode {
+  MODE_UNSPECIFIED = 0;
+  MODE_OFF = 1;
+  MODE_ELECTRIC = 2;
+  MODE_ENERGY_SAVING = 3;
+  MODE_HEAT_PUMP = 4;
+  MODE_HIGH_DEMAND = 5;
+  MODE_GAS = 6;
+  MODE_PERFORMANCE = 7;
+  MODE_VACATION = 8;
+}
+
 message ListDevicesRequest {}
 
 message ListDevicesResponse {
@@ -44,6 +60,20 @@ message GetDeviceResponse {
   Device device = 1;
 }
 
+message SetModeRequest {
+  string serial_number = 1 [(buf.validate.field).string.min_len = 1];
+  Mode mode = 2 [(buf.validate.field).enum = {
+    defined_only: true
+    not_in: [0]
+  }];
+}
+
+message SetModeResponse {
+  // Last-known device state. The mode change is applied asynchronously by the
+  // Rheem cloud, so this reflects the requested mode only after a later poll.
+  Device device = 1;
+}
+
 // EconetService exposes read-only access to Rheem EcoNet device state.
 service EconetService {
   rpc ListDevices(ListDevicesRequest) returns (ListDevicesResponse) {
@@ -52,4 +82,10 @@ service EconetService {
   rpc GetDevice(GetDeviceRequest) returns (GetDeviceResponse) {
     option (google.api.http) = {get: "/v1alpha1/devices/{serial_number}"};
   }
+  rpc SetMode(SetModeRequest) returns (SetModeResponse) {
+    option (google.api.http) = {
+      post: "/v1alpha1/devices/{serial_number}/mode"
+      body: "*"
+    };
+  }
 }