package main

import (
	"flag"
	"log"
	"net"
	"os"
	"os/signal"
	"strings"
	"sync"
	"syscall"

	"github.com/anacrolix/dht/v2"
	analog "github.com/anacrolix/log"
	"golang.org/x/time/rate"

	"github.com/anacrolix/torrent"
	"github.com/anacrolix/torrent/storage"
)

const (
	TorrentExt = ".torrent"
	UserAgent  = "btrtrc/0.2.0"
)

var (
	Cancel = make(chan struct{})
	Jobs   sync.WaitGroup
)

func main() {
	log.SetFlags(log.Ldate | log.Ltime)
	fifosDir := flag.String("fifos", "fifos", "Path to fifos/")
	txsDir := flag.String("txs", "txs", "Path to txs/")
	dhtBoot := flag.String("dht", "dht.cypherpunks.ru:8991",
		"Comma-separated list of DHT bootstrap nodes")
	addr := flag.String("bind", "[::]:6881", "Address to bind to")
	pub4 := flag.String("4", "", "External IPv4 address")
	pub6 := flag.String("6", "", "External IPv6 address")
	debug := flag.Bool("debug", false, "Enable debug messages")
	noDHT := flag.Bool("nodht", false, "Disable DHT")
	rxRate := flag.Int("rx-rate", 0, "Download rate, piece bytes/sec")
	txRate := flag.Int("rt-rate", 0, "Upload rate, bytes/sec")
	verify := flag.Bool("verify", false, "Force verification of provided torrents")
	flag.Parse()

	FIFOsDir = *fifosDir
	TxsDir = *txsDir
	os.MkdirAll(TxsDir, 0777)
	dht.DefaultGlobalBootstrapHostPorts = strings.Split(*dhtBoot, ",")
	cc := torrent.NewDefaultClientConfig()
	cc.Debug = *debug
	cc.DisableAcceptRateLimiting = true
	cc.NoDefaultPortForwarding = true
	cc.DisableWebtorrent = true
	cc.Logger = analog.Default.WithNames("main", "client")
	cc.HTTPUserAgent = UserAgent
	cc.ExtendedHandshakeClientVersion = UserAgent
	cc.DefaultStorage = storage.NewFileWithCompletion(".", NewBFPieceCompletion())
	if *verify {
		doVerify(cc, flag.Args())
		return
	}
	cc.Seed = true
	if *pub4 == "" {
		cc.DisableIPv4 = true
	} else {
		cc.PublicIp4 = net.ParseIP(*pub4).To4()
	}
	if *pub6 == "" {
		cc.DisableIPv6 = true
	} else {
		cc.PublicIp6 = net.ParseIP(*pub6).To16()
	}
	if *txRate != 0 {
		cc.UploadRateLimiter = rate.NewLimiter(rate.Limit(*txRate), 256<<10)
	}
	if *rxRate != 0 {
		cc.DownloadRateLimiter = rate.NewLimiter(rate.Limit(*rxRate), 1<<16)
	}
	cc.NoDHT = *noDHT
	cc.SetListenAddr(*addr)
	client, err := torrent.NewClient(cc)
	if err != nil {
		log.Fatalln("torrent.NewClient:", err)
	}
	defer client.Close()

	needsShutdown := make(chan os.Signal)
	signal.Notify(needsShutdown, syscall.SIGTERM, syscall.SIGINT)
	go func() {
		<-needsShutdown
		close(Cancel)
		client.Close()
	}()

	fifosPrepare()
	log.Println("started", client.PublicIPs())
	Jobs.Add(1)
	go overallStatus(client)
	go fifoList(client)
	go fifoTopSeed(client)
	go fifoDHTList(client)
	go fifoAdd(client)
	go fifoDel(client)
	Jobs.Add(1)
	go txStatsDumper(client)
	<-client.Closed()
	Jobs.Wait()
	fifosCleanup()
	log.Println("finished")
}