Modernize invertergui: MQTT write support, HA integration, UI updates

README.md

@@ -21,7 +21,7 @@ docker run --name invertergui --device /dev/ttyUSB0:/dev/ttyUSB0 -p 8080:8080 gh
 
 ## Requirements
 
-This project makes use of [Go Modules](https://github.com/golang/go/wiki/Modules). The minimum version for Go is 1.16
+This project makes use of [Go Modules](https://github.com/golang/go/wiki/Modules). The minimum supported version for Go is 1.22
 
 ## Getting started
 
@@ -37,10 +37,17 @@ Application Options:
       --cli.enabled     Enable CLI output. [$CLI_ENABLED]
       --mqtt.enabled    Enable MQTT publishing. [$MQTT_ENABLED]
       --mqtt.broker=    Set the host port and scheme of the MQTT broker. (default: tcp://localhost:1883) [$MQTT_BROKER]
-      --mqtt.client_id= Set the client ID for the MQTT connection. (default: interter-gui) [$MQTT_CLIENT_ID]
+      --mqtt.client_id= Set the client ID for the MQTT connection. (default: inverter-gui) [$MQTT_CLIENT_ID]
       --mqtt.topic=     Set the MQTT topic updates published to. (default: invertergui/updates) [$MQTT_TOPIC]
+      --mqtt.command_topic= Set the MQTT topic that receives write commands for Victron settings/RAM variables. (default: invertergui/settings/set) [$MQTT_COMMAND_TOPIC]
+      --mqtt.status_topic=  Set the MQTT topic where write command status updates are published. (default: invertergui/settings/status) [$MQTT_STATUS_TOPIC]
+      --mqtt.ha.enabled Enable Home Assistant MQTT discovery integration. [$MQTT_HA_ENABLED]
+      --mqtt.ha.discovery_prefix= Set Home Assistant MQTT discovery prefix. (default: homeassistant) [$MQTT_HA_DISCOVERY_PREFIX]
+      --mqtt.ha.node_id= Set Home Assistant node ID used for discovery topics and unique IDs. (default: invertergui) [$MQTT_HA_NODE_ID]
+      --mqtt.ha.device_name= Set Home Assistant device display name. (default: Victron Inverter) [$MQTT_HA_DEVICE_NAME]
       --mqtt.username=  Set the MQTT username [$MQTT_USERNAME]
       --mqtt.password=  Set the MQTT password [$MQTT_PASSWORD]
+      --mqtt.password-file= Path to a file containing the MQTT password [$MQTT_PASSWORD_FILE]
       --loglevel=       The log level to generate logs at. ("panic", "fatal", "error", "warn", "info", "debug", "trace") (default: info) [$LOGLEVEL]
 
 Help Options:
@@ -82,6 +89,20 @@ Battery Power: -0.659 W
 Battery Charge: 100.000 %
 ```
 
+The web UI also includes a **Remote Panel Control** section for:
+
+- Remote Panel Mode (`on`, `off`, `charger_only`, `inverter_only`)
+- Remote Panel Current Limit (AC input current limit in amps)
+- Remote Panel Standby (prevent sleep while turned off)
+
+The combined mode + current limit action maps to the same behavior as
+`set_remote_panel_state` in `victron-mk3`.
+
+The backing HTTP API endpoints are:
+
+- `GET/POST /api/remote-panel/state`
+- `GET/POST /api/remote-panel/standby`
+
 ### Munin
 
 The Munin plugin location is at /munin (http://localhost:8080/munin).
@@ -281,16 +302,97 @@ The MQTT client will publish updates to the given broker at the set topic.
 ```bash
 --mqtt.enabled    Enable MQTT publishing. [$MQTT_ENABLED]
 --mqtt.broker=    Set the host port and scheme of the MQTT broker. (default: tcp://localhost:1883) [$MQTT_BROKER]
---mqtt.client_id= Set the client ID for the MQTT connection. (default: interter-gui) [$MQTT_CLIENT_ID]
+--mqtt.client_id= Set the client ID for the MQTT connection. (default: inverter-gui) [$MQTT_CLIENT_ID]
 --mqtt.topic=     Set the MQTT topic updates published to. (default: invertergui/updates) [$MQTT_TOPIC]
+--mqtt.command_topic= Set the MQTT topic that receives write commands for Victron settings/RAM variables. (default: invertergui/settings/set) [$MQTT_COMMAND_TOPIC]
+--mqtt.status_topic=  Set the MQTT topic where write command status updates are published. (default: invertergui/settings/status) [$MQTT_STATUS_TOPIC]
+--mqtt.ha.enabled Enable Home Assistant MQTT discovery integration. [$MQTT_HA_ENABLED]
+--mqtt.ha.discovery_prefix= Set Home Assistant MQTT discovery prefix. (default: homeassistant) [$MQTT_HA_DISCOVERY_PREFIX]
+--mqtt.ha.node_id= Set Home Assistant node ID used for discovery topics and unique IDs. (default: invertergui) [$MQTT_HA_NODE_ID]
+--mqtt.ha.device_name= Set Home Assistant device display name. (default: Victron Inverter) [$MQTT_HA_DEVICE_NAME]
 --mqtt.username=  Set the MQTT username [$MQTT_USERNAME]
 --mqtt.password=  Set the MQTT password [$MQTT_PASSWORD]
+--mqtt.password-file= Path to a file containing the MQTT password [$MQTT_PASSWORD_FILE]
 ```
 
 The MQTT client can be enabled by setting the environment variable `MQTT_ENABLED=true` or flag `--mqtt.enabled`.
 All MQTT configuration can be done via flags or as environment variables.
 The URI for the broker can be configured format should be `scheme://host:port`, where "scheme" is one of "tcp", "ssl", or "ws".
 
+When `--mqtt.command_topic` is configured, the application subscribes to that topic and accepts JSON write commands.
+The recommended command for inverter control follows the same model used by `victron-mk3`:
+
+```json
+{
+  "request_id": "optional-correlation-id",
+  "kind": "panel_state",
+  "switch": "on",
+  "current_limit": 16.5
+}
+```
+
+`switch` supports `charger_only`, `inverter_only`, `on`, and `off` (or numeric values `1..4`).
+`current_limit` is in amps and optional. If omitted, only the switch state is changed.
+To update only the current limit (while preserving the last known mode), send:
+
+```json
+{
+  "kind": "panel_state",
+  "current_limit": 12.0
+}
+```
+
+If no prior mode is known (for example on a fresh broker state), this command is rejected until a mode command is sent once.
+
+Standby can be controlled with:
+
+```json
+{
+  "kind": "standby",
+  "standby": true
+}
+```
+
+Low-level writes are still supported:
+
+```json
+{
+  "kind": "setting",
+  "id": 15,
+  "value": 1
+}
+```
+
+`kind` supports `panel_state`, `setting`, and `ram_var` (with aliases for each).  
+The result is published to `--mqtt.status_topic` with status `ok` or `error`.
+
+### Home Assistant
+
+Enable Home Assistant auto-discovery with:
+
+```bash
+--mqtt.ha.enabled
+```
+
+When enabled, `invertergui` publishes retained discovery payloads and availability under:
+
+- `{topic-root}/homeassistant/availability` (`online`/`offline`)
+- `{discovery_prefix}/sensor/{node_id}/.../config`
+- `{discovery_prefix}/binary_sensor/{node_id}/.../config`
+- `{discovery_prefix}/select/{node_id}/remote_panel_mode/config` (if command topic is configured)
+- `{discovery_prefix}/number/{node_id}/remote_panel_current_limit/config` (if command topic is configured)
+- `{discovery_prefix}/switch/{node_id}/remote_panel_standby/config` (if command topic is configured)
+
+The discovered entities include battery/input/output sensors, a data-valid diagnostic binary sensor,
+plus remote panel controls for:
+
+- `Remote Panel Mode` (`on`, `off`, `charger_only`, `inverter_only`)
+- `Remote Panel Current Limit` (AC input current limit in amps)
+- `Remote Panel Standby` (prevent device sleep while off)
+
+The combined mode + current limit behavior is provided through the `panel_state` MQTT command kind,
+which mirrors `victron_mk3.set_remote_panel_state`.
+
 ## TTY Device
 
 The intertergui application makes use of a serial tty device to monitor the Multiplus.
@@ -360,4 +462,4 @@ This repos includes a [Grafana](https://grafana.com/) dashboard in the [grafana
 [release-badge]: https://img.shields.io/github/v/release/diebietse/invertergui
 [release-link]: https://github.com/diebietse/invertergui/releases
 [codecov-badge]: https://codecov.io/gh/diebietse/invertergui/branch/master/graph/badge.svg?token=xTLfEzoqYF
-[codecov-link]: https://codecov.io/gh/diebietse/invertergui
+[codecov-link]: https://codecov.io/gh/diebietse/invertergui