Quick sound posting bot for Telegram

README.md

This is just a Golang bot quickly thrown together which connects to the Telegram Bot API, waits for messages with specific words to be sent as messages and replies to them with the corresponding audio file.

Building

Make sure you have a standard Go building environment set up (GOPATH should be set up etc.).

Download main.go, make sure dependencies are available (go get -v -d) and then build with go build -v.

Usage

Create a config file config.yml like this one in the working directory:

telegram:
    # Insert your bot token here
    token: 012345678:ABCDEFG...

triggers:
    # This will make the bot respond to the word "pew" by posting the audio file at sounds/pew.ogg
    pew: sounds/pew.ogg
    
    # You can append other triggers similarly here.

Dependencies

• Viper is used for configuration management (will theoretically load configuration from environment variables or system directories as well)
• telegram-bot-api for communication with the Telegram Bot API.

main.go

package main

import (
	"log"
	"strings"

	"github.com/spf13/viper"
	"gopkg.in/telegram-bot-api.v4"
)

// Configuration value paths
const (
	Config_Separator      = "."
	Config_Telegram       = "telegram"
	Config_Telegram_Token = Config_Telegram + Config_Separator + "token"
	Config_Triggers       = "triggers"
)

// Temporary in-memory storage for already uploaded files (Telegram will return IDs for these).
// This can be optimized to be stored permanently so the bot won't have to upload the file again even after restarts.
var (
	audioShareIDs = map[string]string{}
)

// Quick and dirty error handling method.
func must(err error) {
	if err == nil {
		return
	}
	log.Fatal(err)
}

func main() {
	// Add configuration paths
	viper.AddConfigPath("/etc/pew-pew-bot/")
	viper.AddConfigPath("$XDG_CONFIG_DIRS/pew-pew-bot")
	viper.AddConfigPath("$HOME/.pew-pew-bot")
	viper.AddConfigPath(".")

	// Make `pew` trigger a default
	viper.SetDefault(Config_Triggers, map[string]string{
		"pew": "sounds/pew.ogg",
	})

	// Read in config
	must(viper.ReadInConfig())

	// Decode triggers table
	triggers := map[string]string{}
	viper.Sub(Config_Triggers).Unmarshal(&triggers)

	// Set up the Telegram bot
	bot, err := tgbotapi.NewBotAPI(viper.GetString(Config_Telegram_Token))
	must(err)
	//bot.Debug = true

	log.Printf("Authorized on account %s", bot.Self.UserName)

	u := tgbotapi.NewUpdate(0)
	u.Timeout = 60

	updates, err := bot.GetUpdatesChan(u)
	must(err)

	// Listen for incoming updates
	for update := range updates {
		if update.Message == nil {
			continue
		}

		//log.Printf("[%s] %s", update.Message.From.UserName, update.Message.Text)

		// Go through trigger table and check if any of the words there are contained in the message
		for triggerWord, filePath := range triggers {
			if strings.Contains(update.Message.Text, triggerWord) {
				var msg tgbotapi.AudioConfig
				
				// Check whether we need to upload the audio file or we can just reference by ID
				if id, ok := audioShareIDs[filePath]; ok {
					msg = tgbotapi.NewAudioShare(update.Message.Chat.ID, id)
				} else {
					msg = tgbotapi.NewAudioUpload(update.Message.Chat.ID, filePath)
				}
				
				// Mark as reply to the currently parsed message
				msg.ReplyToMessageID = update.Message.MessageID
				
				// Send message to Telegram API
				bot.Send(msg)

				// Prevent bot from sending more than one audio file as a reply by leaving the loop
				break
			}
		}
	}
}