Add automated messages (#2)

automessage.go

@@ -0,0 +1,132 @@
+package main
+
+import (
+	"crypto/sha256"
+	"fmt"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/go-irc/irc"
+	"github.com/pkg/errors"
+	"github.com/robfig/cron/v3"
+	log "github.com/sirupsen/logrus"
+)
+
+var cronParser = cron.NewParser(cron.SecondOptional | cron.Minute | cron.Hour | cron.Dom | cron.Month | cron.Dow)
+
+type autoMessage struct {
+	Channel   string `yaml:"channel"`
+	Message   string `yaml:"message"`
+	UseAction bool   `yaml:"use_action"`
+
+	Cron            string        `yaml:"cron"`
+	MessageInterval int64         `yaml:"message_interval"`
+	OnlyOnLive      bool          `yaml:"only_on_live"`
+	TimeInterval    time.Duration `yaml:"time_interval"`
+
+	disabled              bool
+	lastMessageSent       time.Time
+	linesSinceLastMessage int64
+
+	lock sync.RWMutex
+}
+
+func (a *autoMessage) CanSend() bool {
+	if a.disabled || !a.IsValid() {
+		return false
+	}
+
+	a.lock.RLock()
+	defer a.lock.RUnlock()
+
+	switch {
+	case a.MessageInterval > a.linesSinceLastMessage:
+		// Not enough chatted lines
+		return false
+
+	case a.TimeInterval > 0 && a.lastMessageSent.Add(a.TimeInterval).After(time.Now()):
+		// Simple timer is not yet expired
+		return false
+
+	case a.Cron != "":
+		sched, _ := cronParser.Parse(a.Cron)
+		if sched.Next(a.lastMessageSent).After(time.Now()) {
+			// Cron timer is not yet expired
+			return false
+		}
+	}
+
+	if a.OnlyOnLive {
+		streamLive, err := twitch.HasLiveStream(strings.TrimLeft(a.Channel, "#"))
+		if err != nil {
+			log.WithError(err).Error("Unable to determine channel live status")
+			return false
+		}
+		if !streamLive {
+			return false
+		}
+	}
+
+	return true
+}
+
+func (a *autoMessage) CountMessage(channel string) {
+	if strings.TrimLeft(channel, "#") != strings.TrimLeft(a.Channel, "#") {
+		return
+	}
+
+	a.lock.Lock()
+	defer a.lock.Unlock()
+
+	a.linesSinceLastMessage++
+}
+
+func (a *autoMessage) ID() string {
+	sum := sha256.New()
+
+	fmt.Fprintf(sum, "channel:%q", a.Channel)
+	fmt.Fprintf(sum, "message:%q", a.Message)
+	fmt.Fprintf(sum, "action:%v", a.UseAction)
+
+	return fmt.Sprintf("sha256:%x", sum.Sum(nil))
+}
+
+func (a *autoMessage) IsValid() bool {
+	if a.Cron != "" {
+		if _, err := cronParser.Parse(a.Cron); err != nil {
+			return false
+		}
+	}
+
+	if a.MessageInterval == 0 && a.TimeInterval == 0 && a.Cron == "" {
+		return false
+	}
+
+	return true
+}
+
+func (a *autoMessage) Send(c *irc.Client) error {
+	a.lock.Lock()
+	defer a.lock.Unlock()
+
+	msg := a.Message
+	if a.UseAction {
+		msg = fmt.Sprintf("\001ACTION %s\001", msg)
+	}
+
+	if err := c.WriteMessage(&irc.Message{
+		Command: "PRIVMSG",
+		Params: []string{
+			fmt.Sprintf("#%s", strings.TrimLeft(a.Channel, "#")),
+			msg,
+		},
+	}); err != nil {
+		return errors.Wrap(err, "sending auto-message")
+	}
+
+	a.lastMessageSent = time.Now()
+	a.linesSinceLastMessage = 0
+
+	return nil
+}

config.go

@@ -17,6 +17,7 @@ import (
 )
 
 type configFile struct {
+	AutoMessages         []*autoMessage `yaml:"auto_messages"`
 	Channels             []string       `yaml:"channels"`
 	PermitAllowModerator bool           `yaml:"permit_allow_moderator"`
 	PermitTimeout        time.Duration  `yaml:"permit_timeout"`
@@ -236,6 +237,35 @@ func loadConfig(filename string) error {
 		log.Warn("Loaded config with empty ruleset")
 	}
 
+	for idx, nam := range tmpConfig.AutoMessages {
+		// By default assume last message to be sent now
+		// in order not to spam messages at startup
+		nam.lastMessageSent = time.Now()
+
+		if !nam.IsValid() {
+			log.WithField("index", idx).Warn("Auto-Message configuration is invalid and therefore disabled")
+		}
+
+		if config == nil {
+			// Initial config load, do not update timers
+			continue
+		}
+
+		for _, oam := range config.AutoMessages {
+			if nam.ID() != oam.ID() {
+				continue
+			}
+
+			// We disable the old message as executing it would
+			// mess up the constraints of the new message
+			oam.lock.Lock()
+			oam.disabled = true
+
+			nam.lastMessageSent = oam.lastMessageSent
+			nam.linesSinceLastMessage = oam.linesSinceLastMessage
+		}
+	}
+
 	configLock.Lock()
 	defer configLock.Unlock()
 

go.mod

@@ -9,6 +9,7 @@ require (
 	github.com/go-irc/irc v2.1.0+incompatible
 	github.com/gologme/log v1.2.0
 	github.com/pkg/errors v0.9.1
+	github.com/robfig/cron/v3 v3.0.1
 	github.com/sirupsen/logrus v1.7.0
 	gopkg.in/fsnotify.v1 v1.4.7
 	gopkg.in/yaml.v2 v2.2.2

go.sum

@@ -83,6 +83,8 @@ github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/posener/complete v1.1.1/go.mod h1:em0nMJCgc9GFtwrmVmEMR/ZL6WyhyjMBndrE9hABlRI=
+github.com/robfig/cron/v3 v3.0.1 h1:WdRxkvbJztn8LMz/QEvLN5sBU+xKpSqwwUO1Pjr4qDs=
+github.com/robfig/cron/v3 v3.0.1/go.mod h1:eQICP3HwyT7UooqI/z+Ov+PtYAWygg1TEWWzGIFLtro=
 github.com/ryanuber/columnize v2.1.0+incompatible/go.mod h1:sm1tb6uqfes/u+d4ooFouqFdy9/2g9QGwK3SQygK0Ts=
 github.com/ryanuber/go-glob v1.0.0 h1:iQh3xXAumdQ+4Ufa5b25cRpC5TYKlno6hsv6Cb3pkBk=
 github.com/ryanuber/go-glob v1.0.0/go.mod h1:807d1WSdnB0XRJzKNil9Om6lcp/3a0v4qIHxIXzX/Yc=

irc.go

@@ -167,6 +167,15 @@ func (i ircHandler) handleTwitchPrivmsg(m *irc.Message) {
 		"trailing": m.Trailing(),
 	}).Trace("Received privmsg")
 
+	if m.User != i.user {
+		// Count messages from other users than self
+		configLock.RLock()
+		for _, am := range config.AutoMessages {
+			am.CountMessage(m.Params[0])
+		}
+		configLock.RUnlock()
+	}
+
 	if strings.HasPrefix(m.Trailing(), "!permit") {
 		i.handlePermit(m)
 		return

main.go

@@ -72,6 +72,7 @@ func main() {
 	var (
 		irc               *ircHandler
 		ircDisconnected   = make(chan struct{}, 1)
+		autoMessageTicker = time.NewTicker(time.Second)
 	)
 
 	ircDisconnected <- struct{}{}
@@ -110,6 +111,19 @@ func main() {
 
 			log.Info("Config file reloaded")
 
+		case <-autoMessageTicker.C:
+			configLock.RLock()
+			for _, am := range config.AutoMessages {
+				if !am.CanSend() {
+					continue
+				}
+
+				if err := am.Send(irc.c); err != nil {
+					log.WithError(err).Error("Unable to send automated message")
+				}
+			}
+			configLock.RUnlock()
+
 		}
 	}
 }