package main

import (
	"context"
	"errors"
	"fmt"
	"log"
	"os"
	"runtime"
	"strconv"
	"strings"

	"github.com/SevereCloud/vksdk/v2/api"
	"github.com/SevereCloud/vksdk/v2/events"
	"github.com/SevereCloud/vksdk/v2/longpoll-bot"

	"github.com/s32x/httpclient"

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

var video_links chan (string)

const PCUserAgent string = "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/117.0.0.0 Safari/537.36"
const MobileUserAgent string = "Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Mobile Safari/537.36"

func main() {
	// get config
	mustConfigLoad()
	// create chan
	video_links = make(chan string, Conf.Workers*2)
	// run vk
	go RunVK()
	// run tg
	go RunTG()
	//
	select {}
}

type Config struct {
	Workers  int
	TgAPIKey string
	TgChatID int64
	VkAPIKey string
}

var Conf Config

func mustConfigLoad() {
	var err error
	Conf.Workers, err = strconv.Atoi(os.Getenv("Workers"))
	if err != nil {
		panic(err)
	}
	Conf.TgAPIKey = os.Getenv("TgAPIKey")
	Conf.VkAPIKey = os.Getenv("VkAPIKey")
	Conf.TgChatID, err = strconv.ParseInt(os.Getenv("TgChatID"), 10, 64)
	if err != nil {
		panic(err)
	}
}

func RunVK() {
	vk := api.NewVK(Conf.VkAPIKey)

	// get information about the group
	group, err := vk.GroupsGetByID(nil)
	if err != nil {
		log.Fatal(err)
	}

	// Initializing Long Poll
	lp, err := longpoll.NewLongPoll(vk, group[0].ID)
	if err != nil {
		log.Fatal(err)
	}

	// New message event
	lp.MessageNew(func(_ context.Context, obj events.MessageNewObject) {
		log.Printf("%d: %s", obj.Message.PeerID, obj.Message.Text)

		for _, obj := range obj.Message.Attachments {
		objectsw:
			switch obj.Type {
			case "story":
				// fmt.Printf("Story %+v\n", obj.Story.Video.Files)
				// get video link from struct
				var videolink string
				switch {
				case obj.Story.Video.Files.Mp4_720 != "":
					videolink = obj.Story.Video.Files.Mp4_720
				case obj.Story.Video.Files.Mp4_480 != "":
					videolink = obj.Story.Video.Files.Mp4_480
				case obj.Story.Video.Files.Mp4_360 != "":
					videolink = obj.Story.Video.Files.Mp4_360
				case obj.Story.Video.Files.Mp4_240 != "":
					videolink = obj.Story.Video.Files.Mp4_240
				default:
					error_logging(errors.New("cannot find video link"))
					break objectsw
				}
				// fmt.Println("Story:", videolink)
				error_logging(err)
				// send video to tg
				video_links <- videolink
			}
		}
	})

	// Run Bots Long Poll
	log.Println("[VK] Start Long Poll")
	if err := lp.Run(); err != nil {
		log.Fatal(err)
	}
}

func RunTG() {
	bot, err := tgbotapi.NewBotAPI(Conf.TgAPIKey)
	if err != nil {
		log.Panic(err)
	}

	bot.Debug = false

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

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

	for i := 0; i < Conf.Workers; i++ {
		go tg_worker(i+1, bot)
	}
}

func tg_worker(id int, bot *tgbotapi.BotAPI) {
	for link := range video_links {
		log.Println(fmt.Sprintf("[%d]", id), "Получена ссылка, загружаю:", link)
		// get video by link
		var client *httpclient.Client
		if strings.Contains(link, "VK_ANDROID") {
			// create mobile client
			client = httpclient.New().WithHeader("User-Agent", MobileUserAgent)
		} else {
			// create Desktop client
			client = httpclient.New().WithHeader("User-Agent", PCUserAgent)
		}

		resp, err := client.Get(link).Do()
		error_logging(err)
		body, err := resp.Bytes()
		error_logging(err)
		msg := tgbotapi.NewVideo(Conf.TgChatID, tgbotapi.FileBytes{Name: "story", Bytes: body})
		log.Println(fmt.Sprintf("[%d]", id), "Отправляю видео в телеграм...")
		_, err = bot.Send(msg)
		error_logging(err)
	}
}

// Log errors
func error_logging(err error) {
	if err != nil {
		pc := make([]uintptr, 10)
		n := runtime.Callers(2, pc)
		frames := runtime.CallersFrames(pc[:n])
		frame, _ := frames.Next()
		// fmt.Printf("%s:%d %s\n", frame.File, frame.Line, frame.Function)
		log.Printf("[Parser] error on %s line %d: %s", frame.Function, frame.Line, err)
	}
}