package main

import (
	"errors"
	"fmt"
	"io/ioutil"
	"local/jbtserve/jbt"
	"local/system/sysconf"
	"log"
	"net"
	"net/http"
	"os"
	"os/signal"
	"path"
	"regexp"
	"strings"
	"syscall"

	"github.com/otium/ytdl"
)

var validURL = regexp.MustCompile("(?is)https?://([a-z1-9]+.)+[a-z]+/.*")

func main() {
	if os.Getenv("MNT") == "" {
		os.Setenv("MNT", "./")
	}
	if !strings.HasSuffix(os.Getenv("MNT"), "/") {
		os.Setenv("MNT", os.Getenv("MNT")+"/")
	}
	config := sysconf.Get("ytubespdrun")
	exit := make(chan bool)
	go jbt.RegisterDeregister(config.Name, config.Port, exit)
	log.Print("Listen on", net.JoinHostPort(config.IP, config.Port))
	go func() {
		log.Print(http.ListenAndServe(net.JoinHostPort(config.IP, config.Port), http.HandlerFunc(accept)))
	}()
	sigc := make(chan os.Signal)
	signal.Notify(sigc,
		syscall.SIGINT,
	)
	<-sigc
	<-exit
	<-exit
}

func accept(w http.ResponseWriter, r *http.Request) {
	config := sysconf.Get("ytubespdrun")
	if r.Method != "POST" {
		w.WriteHeader(http.StatusMethodNotAllowed)
		return
	}
	body, err := ioutil.ReadAll(r.Body)
	if err != nil {
		panic(err)
	}
	token := string(body)
	token = strings.Split(token, "&")[0]
	log.Print("Received request", token)
	if !validURL.MatchString(token) {
		w.WriteHeader(http.StatusBadRequest)
		return
	}
	if err := download(token, config.Log); err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		fmt.Fprintf(w, "Cannot download %s, encountered error %v", token, err)
		log.Print("Failed request", token)
		return
	}
	w.WriteHeader(http.StatusOK)
	log.Print("Completed request", token)
}

func download(url, log string) error {
	vid, err := ytdl.GetVideoInfo(url)
	if err != nil {
		return err
	}
	format := vid.Formats.Best(ytdl.FormatExtensionKey)
	if len(format) < 1 {
		return errors.New("no formats available")
	}
	log.Print("Downloading format", format[0].Resolution, format[0].Extension, format[0].Itag, "for video", vid.Title)
	file, err := os.Create(os.Getenv("MNT") + strings.Replace(fmt.Sprintf("%s.%s", vid.Title, format[0].Extension), " ", "_", -1))
	if err != nil {
		return err
	}
	defer file.Close()
	return vid.Download(format[0], file)
}

func pathAdvance(r *http.Request) string {
	p := path.Clean("/" + r.URL.Path)
	i := strings.Index(p[1:], "/") + 1
	if i <= 0 {
		r.URL.Path = "/"
		return p[1:]
	}
	r.URL.Path = p[i:]
	return p[1:i]
}