Improve module concept and config

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

.gitignore

@@ -1 +1,2 @@
+discord-community
 .env

attributeStore.go

@@ -0,0 +1,72 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+)
+
+var (
+	errValueNotSet   = errors.New("specified value not found")
+	errValueMismatch = errors.New("specified value has different format")
+)
+
+type moduleAttributeStore map[string]interface{}
+
+func (m moduleAttributeStore) MustInt64(name string, defVal *int64) int64 {
+	v, err := m.Int64(name)
+	if err != nil {
+		if defVal != nil {
+			return *defVal
+		}
+		panic(err)
+	}
+	return v
+}
+
+func (m moduleAttributeStore) MustString(name string, defVal *string) string {
+	v, err := m.String(name)
+	if err != nil {
+		if defVal != nil {
+			return *defVal
+		}
+		panic(err)
+	}
+	return v
+}
+
+func (m moduleAttributeStore) Int64(name string) (int64, error) {
+	v, ok := m[name]
+	if !ok {
+		return 0, errValueNotSet
+	}
+
+	switch v.(type) {
+	case int:
+		return int64(v.(int)), nil
+	case int16:
+		return int64(v.(int16)), nil
+	case int32:
+		return int64(v.(int32)), nil
+	case int64:
+		return v.(int64), nil
+	}
+
+	return 0, errValueMismatch
+}
+
+func (m moduleAttributeStore) String(name string) (string, error) {
+	v, ok := m[name]
+	if !ok {
+		return "", errValueNotSet
+	}
+
+	if sv, ok := v.(string); ok {
+		return sv, nil
+	}
+
+	if iv, ok := v.(fmt.Stringer); ok {
+		return iv.String(), nil
+	}
+
+	return "", errValueMismatch
+}

config.go

@@ -0,0 +1,38 @@
+package main
+
+import (
+	"os"
+
+	"github.com/pkg/errors"
+	"gopkg.in/yaml.v2"
+)
+
+type (
+	configFile struct {
+		BotToken string `yaml:"bot_token"`
+		GuildID  string `yaml:"guild_id"`
+
+		ModuleConfigs []moduleConfig `yaml:"module_configs"`
+	}
+
+	moduleConfig struct {
+		Type       string               `yaml:"type"`
+		Attributes moduleAttributeStore `yaml:"attributes"`
+	}
+)
+
+func newConfigFromFile(filename string) (*configFile, error) {
+	f, err := os.Open(filename)
+	if err != nil {
+		return nil, errors.Wrap(err, "opening config file")
+	}
+	defer f.Close()
+
+	var (
+		decoder = yaml.NewDecoder(f)
+		tmp     configFile
+	)
+
+	decoder.SetStrict(true)
+	return &tmp, errors.Wrap(decoder.Decode(&tmp), "decoding config")
+}

go.mod

@@ -1,4 +1,4 @@
-module github.com/Luzifer/tezrian-discord
+module github.com/Luzifer/discord-community
 
 go 1.16
 
@@ -9,4 +9,5 @@ require (
 	github.com/pkg/errors v0.9.1
 	github.com/robfig/cron/v3 v3.0.1
 	github.com/sirupsen/logrus v1.8.1
+	gopkg.in/yaml.v2 v2.4.0
 )

helpers.go

@@ -0,0 +1,4 @@
+package main
+
+func ptrInt64(v int64) *int64    { return &v }
+func ptrString(v string) *string { return &v }

main.go

@@ -16,17 +16,13 @@ import (
 
 var (
 	cfg = struct {
-		BotToken       string `flag:"bot-token" description:"Token from the App Bot User section"`
+		Config         string `flag:"config,c" default:"config.yaml" description:"Path to config file"`
-		GuildID        string `flag:"guild-id" description:"ID of the Discord server (guild)"`
 		Listen         string `flag:"listen" default:":3000" description:"Port/IP to listen on"`
 		LogLevel       string `flag:"log-level" default:"info" description:"Log level (debug, info, warn, error, fatal)"`
 		VersionAndExit bool   `flag:"version" default:"false" description:"Prints current version and exits"`
 	}{}
 
-	crontab = cron.New()
+	config *configFile
-	discord *discordgo.Session
-
-	discordHandlers []interface{}
 
 	version = "dev"
 )
@@ -38,7 +34,7 @@ func init() {
 	}
 
 	if cfg.VersionAndExit {
-		fmt.Printf("tezrian-discord %s\n", version)
+		fmt.Printf("discord-community %s\n", version)
 		os.Exit(0)
 	}
 
@@ -50,17 +46,33 @@ func init() {
 }
 
 func main() {
-	var err error
+	var (
+		crontab = cron.New()
+		discord *discordgo.Session
+		err     error
+	)
+
+	if config, err = newConfigFromFile(cfg.Config); err != nil {
+		log.WithError(err).Fatal("Unable to load config file")
+	}
 
 	// Connect to Discord
-	if discord, err = discordgo.New(strings.Join([]string{"Bot", cfg.BotToken}, " ")); err != nil {
+	if discord, err = discordgo.New(strings.Join([]string{"Bot", config.BotToken}, " ")); err != nil {
 		log.WithError(err).Fatal("Unable to create discord client")
 	}
 
 	discord.Identify.Intents = discordgo.IntentsAll
 
-	for _, hdl := range discordHandlers {
+	for _, mc := range config.ModuleConfigs {
-		discord.AddHandler(hdl)
+		logger := log.WithField("module", mc.Type)
+		mod := GetModuleByName(mc.Type)
+		if mod == nil {
+			logger.Fatal("Found configuration for unsupported module")
+		}
+
+		if err = mod.Initialize(crontab, discord, mc.Attributes); err != nil {
+			logger.WithError(err).Fatal("Unable to initialize module")
+		}
 	}
 
 	if err = discord.Open(); err != nil {

mod_presence.go

@@ -6,33 +6,50 @@ import (
 	"strings"
 	"time"
 
+	"github.com/bwmarrin/discordgo"
+	"github.com/pkg/errors"
+	"github.com/robfig/cron/v3"
 	log "github.com/sirupsen/logrus"
 )
 
 func init() {
-	if _, err := crontab.AddFunc("* * * * *", cronUpdatePresence); err != nil {
+	RegisterModule("presence", func() module { return &modPresence{} })
-		log.WithError(err).Fatal("Unable to add cronUpdatePresence function")
-	}
 }
 
-func cronUpdatePresence() {
+type modPresence struct {
+	attrs   moduleAttributeStore
+	discord *discordgo.Session
+}
+
+func (m *modPresence) Initialize(crontab *cron.Cron, discord *discordgo.Session, attrs moduleAttributeStore) error {
+	m.attrs = attrs
+	m.discord = discord
+
+	if _, err := crontab.AddFunc(attrs.MustString("cron", ptrString("* * * * *")), m.cronUpdatePresence); err != nil {
+		return errors.Wrap(err, "adding cron function")
+	}
+
+	return nil
+}
+
+func (m modPresence) cronUpdatePresence() {
 	var nextStream *time.Time = nil
 
 	// FIXME: Get next stream status
 
 	status := "mit Seelen"
 	if nextStream != nil {
-		status = fmt.Sprintf("in: %s", durationToHumanReadable(time.Since(*nextStream)))
+		status = fmt.Sprintf("in: %s", m.durationToHumanReadable(time.Since(*nextStream)))
 	}
 
-	if err := discord.UpdateGameStatus(0, status); err != nil {
+	if err := m.discord.UpdateGameStatus(0, status); err != nil {
 		log.WithError(err).Error("Unable to update status")
 	}
 
 	log.Debug("Updated presence")
 }
 
-func durationToHumanReadable(d time.Duration) string {
+func (m modPresence) durationToHumanReadable(d time.Duration) string {
 	var elements []string
 
 	d = time.Duration(math.Abs(float64(d)))

mod_streamSchedule.go

@@ -12,6 +12,7 @@ import (
 	"github.com/Luzifer/go_helpers/v2/backoff"
 	"github.com/bwmarrin/discordgo"
 	"github.com/pkg/errors"
+	"github.com/robfig/cron/v3"
 	log "github.com/sirupsen/logrus"
 )
 
@@ -22,7 +23,17 @@ const (
 	streamSchedulePastTime  = 15 * time.Minute
 )
 
-type twitchStreamScheduleResponse struct {
+func init() {
+	RegisterModule("schedule", func() module { return &modStreamSchedule{} })
+}
+
+type (
+	modStreamSchedule struct {
+		attrs   moduleAttributeStore
+		discord *discordgo.Session
+	}
+
+	twitchStreamScheduleResponse struct {
 		Data struct {
 			Segments []struct {
 				ID            string     `json:"id"`
@@ -48,14 +59,20 @@ type twitchStreamScheduleResponse struct {
 			Cursor string `json:"cursor"`
 		} `json:"pagination"`
 	}
+)
 
-func init() {
+func (m *modStreamSchedule) Initialize(crontab *cron.Cron, discord *discordgo.Session, attrs moduleAttributeStore) error {
-	if _, err := crontab.AddFunc("*/10 * * * *", cronUpdateSchedule); err != nil {
+	m.attrs = attrs
+	m.discord = discord
+
+	if _, err := crontab.AddFunc(attrs.MustString("cron", ptrString("*/10 * * * *")), m.cronUpdateSchedule); err != nil {
 		log.WithError(err).Fatal("Unable to add cronUpdatePresence function")
 	}
+
+	return nil
 }
 
-func cronUpdateSchedule() {
+func (m modStreamSchedule) cronUpdateSchedule() {
 	var data twitchStreamScheduleResponse
 	if err := backoff.NewBackoff().WithMaxIterations(twitchAPIRequestLimit).Retry(func() error {
 		ctx, cancel := context.WithTimeout(context.Background(), twitchAPIRequestTimeout)
@@ -111,7 +128,7 @@ func cronUpdateSchedule() {
 		}
 
 		msgEmbed.Fields = append(msgEmbed.Fields, &discordgo.MessageEmbedField{
-			Name:   formatGermanShort(*seg.StartTime),
+			Name:   m.formatGermanShort(*seg.StartTime),
 			Value:  title,
 			Inline: false,
 		})
@@ -121,7 +138,7 @@ func cronUpdateSchedule() {
 		}
 	}
 
-	msgs, err := discord.ChannelMessages(discordAnnouncementChannel, 100, "", "", "")
+	msgs, err := m.discord.ChannelMessages(discordAnnouncementChannel, 100, "", "", "")
 	if err != nil {
 		log.WithError(err).Error("Unable to fetch announcement channel messages")
 		return
@@ -139,14 +156,14 @@ func cronUpdateSchedule() {
 	if managedMsg != nil {
 		oldEmbed := managedMsg.Embeds[0]
 
-		if !embedNeedsUpdate(oldEmbed, msgEmbed) {
+		if !m.embedNeedsUpdate(oldEmbed, msgEmbed) {
 			log.Debug("Stream Schedule is up-to-date")
 			return
 		}
 
-		_, err = discord.ChannelMessageEditEmbed(discordAnnouncementChannel, managedMsg.ID, msgEmbed)
+		_, err = m.discord.ChannelMessageEditEmbed(discordAnnouncementChannel, managedMsg.ID, msgEmbed)
 	} else {
-		_, err = discord.ChannelMessageSendEmbed(discordAnnouncementChannel, msgEmbed)
+		_, err = m.discord.ChannelMessageSendEmbed(discordAnnouncementChannel, msgEmbed)
 	}
 	if err != nil {
 		log.WithError(err).Error("Unable to announce streamplan")
@@ -156,7 +173,7 @@ func cronUpdateSchedule() {
 	log.Info("Updated Stream Schedule")
 }
 
-func formatGermanShort(t time.Time) string {
+func (m modStreamSchedule) formatGermanShort(t time.Time) string {
 	wd := map[time.Weekday]string{
 		time.Monday:    "Mo.",
 		time.Tuesday:   "Di.",
@@ -175,7 +192,7 @@ func formatGermanShort(t time.Time) string {
 	return strings.Join([]string{wd, t.In(tz).Format("02.01. 15:04"), "Uhr"}, " ")
 }
 
-func embedNeedsUpdate(o, n *discordgo.MessageEmbed) bool {
+func (m modStreamSchedule) embedNeedsUpdate(o, n *discordgo.MessageEmbed) bool {
 	if o.Title != n.Title {
 		return true
 	}

modules.go

@@ -0,0 +1,45 @@
+package main
+
+import (
+	"sync"
+
+	"github.com/bwmarrin/discordgo"
+	"github.com/pkg/errors"
+	"github.com/robfig/cron/v3"
+)
+
+var (
+	moduleRegister     = map[string]moduleInitFn{}
+	moduleRegisterLock sync.RWMutex
+)
+
+type (
+	module interface {
+		Initialize(crontab *cron.Cron, discord *discordgo.Session, attrs moduleAttributeStore) error
+	}
+
+	moduleInitFn func() module
+)
+
+func GetModuleByName(name string) module {
+	moduleRegisterLock.RLock()
+	defer moduleRegisterLock.RUnlock()
+
+	mif, ok := moduleRegister[name]
+	if !ok {
+		return nil
+	}
+
+	return mif()
+}
+
+func RegisterModule(name string, modInit moduleInitFn) {
+	moduleRegisterLock.Lock()
+	defer moduleRegisterLock.Unlock()
+
+	if _, ok := moduleRegister[name]; ok {
+		panic(errors.Errorf("duplicate module register %q", name))
+	}
+
+	moduleRegister[name] = modInit
+}