joshuar-go-hass-agent/internal/linux/power/powerState.go

156 lines
3.4 KiB
Go

// Copyright (c) 2024 Joshua Rich <joshua.rich@gmail.com>
//
// This software is released under the MIT License.
// https://opensource.org/licenses/MIT
//revive:disable:unused-receiver
package power
import (
"context"
"fmt"
"log/slog"
"strings"
"github.com/joshuar/go-hass-agent/internal/hass/sensor"
"github.com/joshuar/go-hass-agent/internal/hass/sensor/types"
"github.com/joshuar/go-hass-agent/internal/linux"
"github.com/joshuar/go-hass-agent/internal/logging"
"github.com/joshuar/go-hass-agent/pkg/linux/dbusx"
)
const (
suspend powerSignal = iota
shutdown
sleepSignal = "PrepareForSleep"
shutdownSignal = "PrepareForShutdown"
powerStateWorkerID = "power_state_sensor"
)
type powerSignal int
func newPowerState(name powerSignal, value any) sensor.Entity {
return sensor.Entity{
Name: "Power State",
Category: types.CategoryDiagnostic,
State: &sensor.State{
ID: "power_state",
Icon: powerStateIcon(value),
Value: powerStateString(name, value),
Attributes: map[string]any{
"data_source": linux.DataSrcDbus,
},
},
}
}
func powerStateString(signal powerSignal, value any) string {
state, ok := value.(bool)
if !ok {
return sensor.StateUnknown
}
switch {
case signal == suspend && state:
return "Suspended"
case signal == shutdown && state:
return "Powered Off"
default:
return "Powered On"
}
}
func powerStateIcon(value any) string {
state, ok := value.(string)
if !ok {
return "mdi:power-on"
}
switch state {
case "Suspended":
return "mdi:power-sleep"
case "Powered Off":
return "mdi:power-off"
default:
return "mdi:power-on"
}
}
type stateWorker struct {
triggerCh chan dbusx.Trigger
}
func (w *stateWorker) Events(ctx context.Context) (<-chan sensor.Entity, error) {
sensorCh := make(chan sensor.Entity)
// Watch for state changes.
go func() {
defer close(sensorCh)
for {
select {
case <-ctx.Done():
return
case event := <-w.triggerCh:
switch {
case strings.HasSuffix(event.Signal, sleepSignal):
sensorCh <- newPowerState(suspend, event.Content[0])
case strings.HasSuffix(event.Signal, shutdownSignal):
sensorCh <- newPowerState(shutdown, event.Content[0])
}
}
}
}()
// Send an initial state update (on, not suspended).
go func() {
sensors, err := w.Sensors(ctx)
if err != nil {
logging.FromContext(ctx).
With(slog.String("worker", powerStateWorkerID)).
Debug("Could not retrieve power state.", slog.Any("error", err))
return
}
for _, s := range sensors {
sensorCh <- s
}
}()
return sensorCh, nil
}
// Sensors returns the current sensors states. Assuming that if this is called,
// then the machine is obviously running and not suspended, otherwise this
// couldn't be called?
func (w *stateWorker) Sensors(_ context.Context) ([]sensor.Entity, error) {
return []sensor.Entity{newPowerState(shutdown, false)}, nil
}
func NewStateWorker(ctx context.Context) (*linux.EventSensorWorker, error) {
worker := linux.NewEventSensorWorker(powerStateWorkerID)
bus, ok := linux.CtxGetSystemBus(ctx)
if !ok {
return worker, linux.ErrNoSystemBus
}
triggerCh, err := dbusx.NewWatch(
dbusx.MatchPath(loginBasePath),
dbusx.MatchInterface(managerInterface),
dbusx.MatchMembers(sleepSignal, shutdownSignal),
).Start(ctx, bus)
if err != nil {
return worker, fmt.Errorf("unable to set-up D-Bus watch for power state: %w", err)
}
worker.EventSensorType = &stateWorker{
triggerCh: triggerCh,
}
return worker, nil
}