// Fantasy World Zookeeper Bot
// Copyright (c) 2018 Vladimir "fat0troll" Hodakov

package telegram

import (
	"encoding/json"
	http "github.com/valyala/fasthttp"
	"gitlab.com/toby3d/telegram"
	"golang.org/x/net/proxy"
	"source.hodakov.me/fat0troll/fwzookeeper/internal/router"
	"net"
)

func proxyDialer(addr string) (net.Conn, error) {
	log.Debug().Msgf("Proxy used: %s", c.Config.Telegram.Proxy.Address)
	proxyAuth := proxy.Auth{}
	if c.Config.Telegram.Proxy.Username != "" {
		proxyAuth.User = c.Config.Telegram.Proxy.Username
		proxyAuth.Password = c.Config.Telegram.Proxy.Password
	}
	var dialProxy proxy.Dialer
	var err error
	dialProxy, err = proxy.SOCKS5("tcp", c.Config.Telegram.Proxy.Address, &proxyAuth, proxy.Direct)
	if err != nil {
		log.Fatal().Err(err).Msg("Failed to dial proxy")
	}

	return dialProxy.Dial("tcp", addr)
}

// Bot returns Telegram instance
func Bot() *telegram.Bot {
	return bot
}

// StartBot starts connection with Telegram
func StartBot() {
	// Any errors here considered fatal, because main purpose of this app is Telegram interactions
	var err error
	var updates telegram.UpdatesChannel
	if c.Config.Telegram.Proxy.Enabled {
		bot = new(telegram.Bot)
		client := new(http.Client)
		client.Dial = proxyDialer
		bot.SetClient(client)
		bot.AccessToken = c.Config.Telegram.Token
		bot.User, err = bot.GetMe()
	} else {
		bot, err = telegram.New(c.Config.Telegram.Token)
	}
	if err != nil {
		log.Fatal().Err(err)
	}

	if c.Config.Telegram.Webhook.Enabled {
		var url http.URI
		url.Parse(nil, []byte("https://"+c.Config.Telegram.Webhook.Domain))
		if len(url.Host()) == 0 {
			log.Fatal().Msg("Can't parse webhook URL: got empty host")
		}
		log.Info().Msg("Trying to set webhook: " + url.String() + bot.AccessToken)

		webhook := telegram.NewWebhook(url.String()+bot.AccessToken, nil)
		webhook.MaxConnections = 40

		updates = bot.NewWebhookChannel(&url, webhook, "", "", c.Config.Telegram.Webhook.Listen)
	} else {
		log.Warn().Msg("Using long-polling for updates (not recommended)")
		var info *telegram.WebhookInfo
		info, err = bot.GetWebhookInfo()
		if err != nil {
			log.Fatal().Err(err)
		}
		if info != nil && info.URL != "" {
			log.Info().Msg("Deleting old webhook...")
			_, err := bot.DeleteWebhook()
			if err != nil {
				log.Fatal().Err(err)
			}
		}
		updatesParams := telegram.GetUpdatesParameters{
			Offset:  0,
			Limit:   100,
			Timeout: 60,
		}
		updates = bot.NewLongPollingChannel(&updatesParams)
	}

	log.Info().Msg("Connection with Telegram established")

	for update := range updates {
		updateText, _ := json.Marshal(update)
		log.Debug().Msgf("%s", string(updateText))
		go router.Respond(update)
	}
}