Provide central cron service to plugins

Signed-off-by: Knut Ahlers <knut@ahlers.me>

action_core.go

@@ -36,6 +36,7 @@ func getRegistrationArguments() plugins.RegistrationArguments {
 		FormatMessage:            formatMessage,
 		GetLogger:                func(moduleName string) *log.Entry { return log.WithField("module", moduleName) },
 		RegisterActor:            registerAction,
+		RegisterCron:             cronService.AddFunc,
 		RegisterTemplateFunction: tplFuncs.Register,
 		SendMessage:              sendMessage,
 	}

main.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/go-irc/irc"
 	"github.com/pkg/errors"
+	"github.com/robfig/cron/v3"
 	log "github.com/sirupsen/logrus"
 
 	"github.com/Luzifer/go_helpers/v2/str"
@@ -35,6 +36,8 @@ var (
 	config     *configFile
 	configLock = new(sync.RWMutex)
 
+	cronService *cron.Cron
+
 	sendMessage func(m *irc.Message) error
 
 	store        = newStorageFile(false)
@@ -73,12 +76,13 @@ func init() {
 func main() {
 	var err error
 
+	cronService = cron.New()
+	twitchClient = twitch.New(cfg.TwitchClient, cfg.TwitchToken)
+
 	if err = loadPlugins(cfg.PluginDir); err != nil {
 		log.WithError(err).Fatal("Unable to load plugins")
 	}
 
-	twitchClient = twitch.New(cfg.TwitchClient, cfg.TwitchToken)
-
 	if err = loadConfig(cfg.Config); err != nil {
 		log.WithError(err).Fatal("Initial config load failed")
 	}
@@ -107,6 +111,8 @@ func main() {
 		autoMessageTicker = time.NewTicker(time.Second)
 	)
 
+	cronService.Start()
+
 	ircDisconnected <- struct{}{}
 
 	for {

plugins/interface.go

@@ -2,6 +2,7 @@ package plugins
 
 import (
 	"github.com/go-irc/irc"
+	"github.com/robfig/cron/v3"
 	log "github.com/sirupsen/logrus"
 )
 
@@ -22,6 +23,8 @@ type (
 
 	ActorRegistrationFunc func(ActorCreationFunc)
 
+	CronRegistrationFunc func(spec string, cmd func()) (cron.EntryID, error)
+
 	LoggerCreationFunc func(moduleName string) *log.Entry
 
 	MsgFormatter func(tplString string, m *irc.Message, r *Rule, fields map[string]interface{}) (string, error)
@@ -36,6 +39,8 @@ type (
 		GetLogger LoggerCreationFunc
 		// RegisterActor is used to register a new IRC rule-actor implementing the Actor interface
 		RegisterActor ActorRegistrationFunc
+		// RegisterCron is a method to register cron functions in the global cron instance
+		RegisterCron CronRegistrationFunc
 		// RegisterTemplateFunction can be used to register a new template functions
 		RegisterTemplateFunction TemplateFuncRegister
 		// SendMessage can be used to send a message not triggered by an event