Telegram support (#488)

telegram/bot.go

@@ -0,0 +1,155 @@
+package telegram
+
+import (
+	"fmt"
+	"sync"
+	"time"
+
+	"github.com/NicoNex/echotron/v3"
+	"github.com/labstack/gommon/log"
+	"github.com/ngoduykhanh/wireguard-ui/store"
+)
+
+type SendRequestedConfigsToTelegram func(db store.IStore, userid int64) []string
+
+type TgBotInitDependencies struct {
+	DB                             store.IStore
+	SendRequestedConfigsToTelegram SendRequestedConfigsToTelegram
+}
+
+var (
+	Token            string
+	AllowConfRequest bool
+	FloodWait        int
+	LogLevel         log.Lvl
+
+	Bot      *echotron.API
+	BotMutex sync.RWMutex
+
+	floodWait        = make(map[int64]int64, 0)
+	floodMessageSent = make(map[int64]struct{}, 0)
+)
+
+func Start(initDeps TgBotInitDependencies) (err error) {
+	ticker := time.NewTicker(time.Minute)
+	defer func() {
+		if err != nil {
+			BotMutex.Lock()
+			Bot = nil
+			BotMutex.Unlock()
+			ticker.Stop()
+		}
+		if r := recover(); r != nil {
+			err = fmt.Errorf("[PANIC] recovered from panic: %v", r)
+		}
+	}()
+
+	token := Token
+	if token == "" || len(token) < 30 {
+		return
+	}
+
+	bot := echotron.NewAPI(token)
+
+	res, err := bot.GetMe()
+	if !res.Ok || err != nil {
+		log.Warnf("[Telegram] Unable to connect to bot.\n%v\n%v", res.Description, err)
+		return
+	}
+
+	BotMutex.Lock()
+	Bot = &bot
+	BotMutex.Unlock()
+
+	if LogLevel <= log.INFO {
+		fmt.Printf("[Telegram] Authorized as %s\n", res.Result.Username)
+	}
+
+	go func() {
+		for range ticker.C {
+			updateFloodWait()
+		}
+	}()
+
+	if !AllowConfRequest {
+		return
+	}
+
+	updatesChan := echotron.PollingUpdatesOptions(token, false, echotron.UpdateOptions{AllowedUpdates: []echotron.UpdateType{echotron.MessageUpdate}})
+	for update := range updatesChan {
+		if update.Message != nil {
+			userid := update.Message.Chat.ID
+			if _, wait := floodWait[userid]; wait {
+				if _, notified := floodMessageSent[userid]; notified {
+					continue
+				}
+				floodMessageSent[userid] = struct{}{}
+				bot.SendMessage(
+					fmt.Sprintf("You can only request your configs once per %d minutes", FloodWait),
+					userid,
+					&echotron.MessageOptions{
+						ReplyToMessageID: update.Message.ID,
+					})
+				continue
+			}
+			floodWait[userid] = time.Now().Unix()
+
+			failed := initDeps.SendRequestedConfigsToTelegram(initDeps.DB, userid)
+			if len(failed) > 0 {
+				messageText := "Failed to send configs:\n"
+				for _, f := range failed {
+					messageText += f + "\n"
+				}
+				bot.SendMessage(
+					messageText,
+					userid,
+					&echotron.MessageOptions{
+						ReplyToMessageID: update.Message.ID,
+					})
+			}
+		}
+	}
+	return err
+}
+
+func SendConfig(userid int64, clientName string, confData, qrData []byte, ignoreFloodWait bool) error {
+	BotMutex.RLock()
+	defer BotMutex.RUnlock()
+
+	if Bot == nil {
+		return fmt.Errorf("telegram bot is not configured or not available")
+	}
+
+	if _, wait := floodWait[userid]; wait && !ignoreFloodWait {
+		return fmt.Errorf("this client already got their config less than %d minutes ago", FloodWait)
+	}
+
+	if !ignoreFloodWait {
+		floodWait[userid] = time.Now().Unix()
+	}
+
+	qrAttachment := echotron.NewInputFileBytes("qr.png", qrData)
+	_, err := Bot.SendPhoto(qrAttachment, userid, &echotron.PhotoOptions{Caption: clientName})
+	if err != nil {
+		log.Error(err)
+		return fmt.Errorf("unable to send qr picture")
+	}
+
+	confAttachment := echotron.NewInputFileBytes(clientName+".conf", confData)
+	_, err = Bot.SendDocument(confAttachment, userid, nil)
+	if err != nil {
+		log.Error(err)
+		return fmt.Errorf("unable to send conf file")
+	}
+	return nil
+}
+
+func updateFloodWait() {
+	thresholdTS := time.Now().Unix() - 60*int64(FloodWait)
+	for userid, ts := range floodWait {
+		if ts < thresholdTS {
+			delete(floodWait, userid)
+			delete(floodMessageSent, userid)
+		}
+	}
+}