Allow MQTT to update local antenna display names

[s53zo]

Problem

AetherSDR now supports local antenna display names for canonical radio antenna tokens such as ANT1, ANT2, RX_A, and XVTA. In real shacks, those local names can change dynamically when an external coax switch or automation system changes the routing. Examples include 4O3A Antenna Genius 8x2 setups and other station controllers that decide which physical antenna is currently connected to each radio port.

Without an automation input, the operator has to manually keep AetherSDR's local labels synchronized with external routing state.

Proposal

Let the MQTT station automation integration update AetherSDR's local antenna display aliases while preserving canonical radio protocol tokens.

Suggested default topic contract:

• Per-port update: aethersdr/antenna/name/ANT1 with payload 80m Dipole
• Bulk update: aethersdr/antenna/names with payload {"ANT1":"80m Dipole","ANT2":"Hexbeam","RX_A":"Beverage NE"}
• Empty per-port payload clears that local name
• In bulk JSON, "" or null clears that local name

These updates should call the existing local alias APIs only. Radio commands must continue using canonical tokens like ANT1, ANT2, and RX_A.

Topic design note

The initial implementation can use fixed AetherSDR-owned default topics as a stable integration contract. A configurable topic prefix may be useful later for multi-station or site-specific MQTT namespaces, but fixed defaults keep the first version small and predictable.

Acceptance criteria

• MQTT messages can set and clear antenna aliases without a live broker in unit tests.
• Bulk JSON and per-port topics are both supported.
• Invalid token keys are ignored.
• MQTT aliases do not apply while no radio is connected, and queued aliases cannot leak to a later radio.
• Existing antenna commands continue to send canonical tokens.

[aethersdr-agent]

Triage

Current state (what's already in place)

• Local alias APIs — RadioModel::setAntennaAlias(token, alias) and RadioModel::clearAntennaAlias(token) already exist (src/models/RadioModel.cpp:600 and :620), backed by AntennaAliasStore (src/models/AntennaAliasStore.cpp) which persists per-radio under a key derived from antennaAliasRadioKey(). Empty/whitespace alias on setAntennaAlias already routes through clearAntennaAlias, so a single setter handles set-and-clear cleanly.
• MQTT transport — MqttClient (src/core/MqttClient.h) emits messageReceived(topic, payload). MqttApplet::onMessageReceived (src/gui/MqttApplet.cpp:260) is the existing fan-out point; today it only updates the log and the panadapter overlay.
• Wiring point — MainWindow constructs the client and the applet together (src/gui/MainWindow.cpp:1697-1725) under #ifdef HAVE_MQTT, and that's where new applet→model signals should be hooked up so we don't pull RadioModel into the applet itself.
• Token validation — RadioModel::knownAntennaTokens() (src/models/RadioModel.cpp:632) aggregates current radio antennaList() plus per-slice RX/TX antenna sets, which is the right "what is real on this radio" source. A fixed allowlist would over-reject (e.g. a Flex 6700 exposes XVTA/XVTB only when a transverter is configured) and under-document (RX_B on 6700-class).

Proposed implementation

1. MqttApplet::onMessageReceived — after the existing display routing, match against two fixed topic patterns:
   • aethersdr/antenna/name/<TOKEN> → emit a new antennaAliasRequested(token, alias) signal. Empty payload ⇒ alias is empty string (the existing setter clears).
   • aethersdr/antenna/names → parse payload as JSON object; for each entry emit antennaAliasRequested(key, value). Treat JSON null and "" as a clear. Malformed JSON ⇒ ignore silently (log to the applet's message pane for debuggability).
2. Auto-subscribe the two fixed topics on every connect (in addition to the user's MqttTopics) so the contract is stable and discoverable. Don't mix them into MqttTopics (would let the user accidentally unsubscribe them).
3. MainWindow — connect MqttApplet::antennaAliasRequested to a slot that:
   • Drops the message if !m_radioModel->isConnected() (acceptance criterion: "MQTT aliases do not apply while no radio is connected, and queued aliases cannot leak to a later radio"). Do not queue.
   • Otherwise validates the token against m_radioModel->knownAntennaTokens() and, if known, calls setAntennaAlias(token, alias). Unknown tokens are silently dropped.
4. Tests — add tests/mqtt_antenna_alias_test.cpp following the tests/antenna_alias_test.cpp pattern. Drive the MQTT handler directly with synthetic (topic, payload) pairs (no broker) — assert per-port set, per-port clear (empty payload), bulk JSON set, bulk JSON clear via null/"", invalid-token rejection, and the "no radio connected ⇒ no-op, no state retained for next connect" case. Add to CMakeLists.txt next to antenna_alias_test.

Files touched

• src/gui/MqttApplet.h/.cpp — new signal + topic-pattern parsing, auto-subscribe defaults.
• src/gui/MainWindow.cpp — connect new signal into RadioModel with the "no radio ⇒ drop" guard (inside the existing #ifdef HAVE_MQTT block at :1696).
• tests/mqtt_antenna_alias_test.cpp + CMakeLists.txt registration.

Notes for maintainer review

• No changes needed to radio command formatting — setAntennaAlias only writes to AntennaAliasStore; radio commands continue to use canonical tokens via the existing slice/antenna code paths.
• Topic prefix stays hard-coded for v1 per the issue's own guidance. A MqttAntennaTopicPrefix setting can be layered on later without breaking the contract.
• Worth confirming: should the bulk topic be incremental (only keys present in JSON change) or replace-all (any token not in the JSON is cleared)? The issue's example reads as incremental, which is also safer for multi-publisher setups. Recommending incremental unless you want replace-all.

[aethersdr-agent]

Claude here — fix applied in PR #2882: #2882

What was changed: Route MQTT updates to local antenna display names (#2880). Principle I.

Files touched:

• CMakeLists.txt
• src/core/MqttAntennaAliasParser.cpp
• src/core/MqttAntennaAliasParser.h
• src/gui/MainWindow.cpp
• src/gui/MqttApplet.cpp
• src/gui/MqttApplet.h
• tests/mqtt_antenna_alias_test.cpp

— AetherClaude (automated agent for AetherSDR)