RITlug/teleirc

// Package telegram handles all Telegram-side logic.
package telegram

import (
    tgbotapi "github.com/go-telegram-bot-api/telegram-bot-api"
    "github.com/ritlug/teleirc/internal"
)

/*
Client contains information for the Telegram bridge, including
the TelegramSettings needed to run the bot
*/
type Client struct {
    api           *tgbotapi.BotAPI
    Settings      *internal.TelegramSettings
    IRCSettings   *internal.IRCSettings
    ImgurSettings *internal.ImgurSettings
    logger        internal.DebugLogger
    sendToIrc     func(string)
}

/*
NewClient creates a new Telegram bot client
*/
func NewClient(settings *internal.TelegramSettings, ircsettings *internal.IRCSettings, imgur *internal.ImgurSettings, tgapi *tgbotapi.BotAPI, logger internal.DebugLogger) *Client {
    logger.LogInfo("Creating new Telegram bot client...")
    return &Client{api: tgapi, Settings: settings, IRCSettings: ircsettings, ImgurSettings: imgur, logger: logger}
}

/*
SendMessage sends a message to the Telegram channel specified in the settings
*/
func (tg *Client) SendMessage(msg string) {
    newMsg := tgbotapi.NewMessage(tg.Settings.ChatID, "")
    newMsg.Text = msg

    if _, err := tg.api.Send(newMsg); err != nil {
        var attempts int = 0
        // Try resending 3 times if the message is successfully sent
        for err != nil && attempts < 3 {
            tg.logger.LogError(err)
            attempts++
            _, err = tg.api.Send(newMsg)
        }
    }
}

/*
StartBot adds necessary handlers to the client and then connects,
returning any errors that occur
*/
func (tg *Client) StartBot(errChan chan<- error, sendMessage func(string)) {
    tg.logger.LogInfo("Starting up Telegram bot...")
    var err error
    tg.api, err = tgbotapi.NewBotAPI(tg.Settings.Token)
    if err != nil {
        tg.logger.LogError(err)
        errChan <- err
    }

    if tg.api == nil {
        tg.logger.LogError("Failed to authenticate to Telegram")
        errChan <- err
    }

    tg.logger.LogInfo("Authorized on account", tg.api.Self.UserName)
    tg.sendToIrc = sendMessage

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

    updates, err := tg.api.GetUpdatesChan(u)
    if err != nil {
        errChan <- err
        tg.logger.LogError(err)
    }

    updateHandler(tg, updates)

    errChan <- nil
}