package main

import (
	"flag"
	"fmt"
	"net"
	"os"
	"strconv"
	"strings"
	"sync"
	"time"

	tgbotapi "github.com/go-telegram-bot-api/telegram-bot-api/v5"
	"github.com/probakowski/go-satel"
)

const (
	MessageNotMoreOftenThanSeconds = 15
)

type TgSender struct {
	bot *tgbotapi.BotAPI
}

func (self TgSender) Send(msg GenericMessage) error {
	to_send := tgbotapi.NewMessage(msg.chat_id, msg.msg)
	_, err := self.bot.Send(to_send)
	return err
}

func send_tg_message(tg_events chan GenericMessage, msg string, chat_ids []int64) {
	for _, chat_id := range chat_ids {
		tg_events <- GenericMessage{chat_id, msg}
	}
}

type RealSleeper struct {
	duration time.Duration
}

func (self RealSleeper) Sleep(ch chan<- interface{}) {
	time.Sleep(self.duration)
	ch <- nil
}

func main() {
	var (
		wg        sync.WaitGroup
		tg_events = make(chan GenericMessage)
		sleeper   = RealSleeper{time.Second * 15}
	)
	satel_api_addr := flag.String("satel-addr", "", "Address that should be used to connect to the SATEL device")
	satel_api_port := flag.String("satel-port", "7094", "Port that should be used to connect to the SATEL device")
	chat_id_raw := flag.String("tg-chat-id", "", "Telegram Chat ID where to send updates. Use \",\" to specify multiple IDs.")
	flag.Parse()

	if len(*satel_api_addr) == 0 || len(*satel_api_port) == 0 || len(*chat_id_raw) == 0 {
		fmt.Println("Use --satel-addr=ADDR, --satel-port=PORT and --tg-chat-id=CHAT_ID command line flags to continue.")
		os.Exit(1)
	}
	chat_ids_strings := strings.Split(*chat_id_raw, ",")
	var chat_ids []int64
	for _, chat_id_str := range chat_ids_strings {
		chat_id, err := strconv.ParseInt(chat_id_str, 10, 64)
		if err != nil {
			fmt.Printf("Tried to use a non-int value for one of tg_chat_ids: %s. That's bad.", chat_id_str)
			os.Exit(1)
		}
		chat_ids = append(chat_ids, chat_id)
	}

	satel_addr := fmt.Sprintf("%s:%s", *satel_api_addr, *satel_api_port)
	satel_conn, err := net.Dial("tcp", satel_addr)
	if err != nil {
		panic(err)
	}
	s := satel.NewConfig(satel_conn, satel.Config{EventsQueueSize: 1000})
	bot, err := tgbotapi.NewBotAPI(os.Getenv("TELEGRAM_APITOKEN"))
	if err != nil {
		panic(err)
	}

	tgSender := TgSender{bot}
	go tg_sender_worker(tg_events, tgSender, &wg, sleeper)
	for e, ok := <-s.Events; ok; e, ok = <-s.Events {
		send_tg_message(tg_events, fmt.Sprintln("Change from SATEL: ", "type", e.Type, "index", e.Index, "value", e.Value), chat_ids)
	}

	close(tg_events)
	wg.Wait()
}