Added dbus service for playing sounds

.goreleaser.yml

@@ -35,5 +35,6 @@ nfpms:
   bindir: /usr/bin
   files:
     "_release/audiobait.service": "/etc/systemd/system/audiobait.service"
+    "_release/org.cacophony.Audiobait.conf": "/etc/dbus-1/system.d/org.cacophony.Audiobait.conf"
   scripts:
       postinstall: "_release/postinstall.sh"

_release/org.cacophony.Audiobait.conf

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?> <!-- -*- XML -*- -->
+
+<!DOCTYPE busconfig PUBLIC
+ "-//freedesktop//DTD D-BUS Bus Configuration 1.0//EN"
+ "http://www.freedesktop.org/standards/dbus/1.0/busconfig.dtd">
+<busconfig>
+  <policy user="root">
+    <allow own="org.cacophony.Audiobait"/>
+  </policy>
+
+  <policy context="default">
+    <allow send_destination="org.cacophony.Audiobait"/>
+  </policy>
+</busconfig>

cmd/audiobait/main.go

@@ -75,6 +75,14 @@ func runMain() error {
 		return err
 	}
 
+	soundCard := NewSoundCardPlayer(conf.Card, conf.VolumeControl)
+
+	service, err := startService(conf.Dir, soundCard)
+	if err != nil {
+		return err
+	}
+	log.Println("started audiobait dbus servie")
+
 	// Make sure the path to where we keep the schedule and audio files is OK.
 	if err := createAudioPath(conf.Dir); err != nil {
 		// This is a pretty fundamental error.  We can't do anything without this.
@@ -85,12 +93,11 @@ func runMain() error {
 	// Start checking for new schedules
 	dl := NewDownloader(conf.Dir)
 
-	soundCard := NewSoundCardPlayer(conf.Card, conf.VolumeControl)
-
 	var playTime <-chan time.Time
 	for {
 		log.Print("loading schedule from disk")
-		player, schedule, err := createPlayer(soundCard, conf.Dir)
+		player, schedule, err := createPlayer(soundCard, conf.Dir) //TODO add trigger output
+		service.setPlayer(player)
 		if err != nil {
 			log.Printf("error creating player: %v (will wait for schedule update)", err)
 			playTime = nil

cmd/audiobait/service.go

@@ -0,0 +1,127 @@
+/*
+audiobait - play sounds to lure animals for The Cacophony Project API.
+Copyright (C) 2021, The Cacophony Project
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package main
+
+import (
+	"errors"
+	"sync"
+
+	"github.com/TheCacophonyProject/audiobait/audiofilelibrary"
+	"github.com/TheCacophonyProject/audiobait/playlist"
+	"github.com/godbus/dbus"
+	"github.com/godbus/dbus/introspect"
+)
+
+const (
+	dbusName = "org.cacophony.Audiobait"
+	dbusPath = "/org/cacophony/Audiobait"
+)
+
+var mu = sync.RWMutex{}
+
+type service struct {
+	soundCard SoundCardPlayer
+	player    *playlist.SchedulePlayer
+	soundDir  string
+}
+
+func startService(soundDir string, soundCard SoundCardPlayer) (*service, error) {
+	conn, err := dbus.SystemBus()
+	if err != nil {
+		return nil, err
+	}
+	reply, err := conn.RequestName(dbusName, dbus.NameFlagDoNotQueue)
+	if err != nil {
+		return nil, err
+	}
+	if reply != dbus.RequestNameReplyPrimaryOwner {
+		return nil, errors.New("name already taken")
+	}
+
+	s := &service{
+		soundDir:  soundDir,
+		soundCard: soundCard,
+	}
+	if err := conn.Export(s, dbusPath, dbusName); err != nil {
+		return nil, err
+	}
+	if err := conn.Export(genIntrospectable(s), dbusPath, "org.freedesktop.DBus.Introspectable"); err != nil {
+		return nil, err
+	}
+	return s, nil
+}
+
+func (s *service) setPlayer(player *playlist.SchedulePlayer) {
+	mu.Lock()
+	defer mu.Unlock()
+	s.player = player
+}
+
+func (s service) Play(audioFileId, volume, priority int, makeEvent bool) (bool, *dbus.Error) {
+	mu.Lock()
+	defer mu.Unlock()
+	library, err := audiofilelibrary.OpenLibrary(s.soundDir, scheduleFilename)
+	if err != nil {
+		return false, dbusErr("Play", err)
+	}
+	path := s.soundDir + "/" + library.FilesByID[audioFileId]
+	if err := s.soundCard.Play(path, volume); err != nil {
+		return false, dbusErr("Play", err)
+	}
+	return true, nil
+}
+
+func dbusErr(name string, err error) *dbus.Error {
+	if err == nil {
+		return nil
+	}
+	return &dbus.Error{
+		Name: dbusName + "." + name,
+		Body: []interface{}{err.Error()},
+	}
+}
+
+func genIntrospectable(v interface{}) introspect.Introspectable {
+	node := &introspect.Node{
+		Interfaces: []introspect.Interface{{
+			Name:    dbusName,
+			Methods: introspect.Methods(v),
+		}},
+	}
+	return introspect.NewIntrospectable(node)
+}
+
+/*	//TODO
+func (s *service) PlayTrigger(trigger string, volume, priority int, makeEvent bool) (bool, *dbus.Error) {
+	mu.Lock()
+	defer mu.Unlock()
+	return true, nil
+}
+
+func (s service) Status() *dbus.Error {
+	mu.Lock()
+	defer mu.Unlock()
+	return nil
+}
+
+func (s service) Mute(priority int) *dbus.Error {
+	return nil
+}
+
+*/

playlist/schedule.go

@@ -39,6 +39,7 @@ type Combo struct {
 	Waits   []int
 	Volumes []int
 	Sounds  []string
+	Trigger string
 }
 
 func ParseJSONConfigFile(jsonAsString string, schedule *Schedule) error {