package main

import (
	"bufio"
	"fmt"
	"log"
	"os"
	"regexp"
	//"path/filepath"

	. "github.com/kkdai/youtube"
)

type Batch struct {
	batchfile, destDir string
}

func NewBatch(batchFile, destinationDir string) *Batch {
	return &Batch{batchfile: batchFile, destDir: destinationDir}
}

func (b *Batch) Start() {
	//Start downloading all videos

	//open the file containing yt links
	linkfile, err := os.Open(b.batchfile)
	if err != nil {
		log.Fatal(err)
	}
	defer linkfile.Close()

	//Create scanner to go line by line through the file
	//This scanner allows 65536 characters per line.
	//That should be enough for yt links.
	scanner := bufio.NewScanner(linkfile)

	for scanner.Scan() {
		//Call download
		go downloadVideo(b.destDir, scanner.Text())
	}

	if err := scanner.Err(); err != nil {
		log.Fatal(err)
	}
}

func downloadVideo(destDir, url string) {
	// NewYoutube(debug) if debug parameter will set true we can log of messages
	y := NewYoutube(false)
	y.DecodeURL(url)
	re := regexp.MustCompile("(mp4|webm|3gpp)")
	fileext := re.FindString(y.StreamList[0]["type"])
	filename := fmt.Sprintf("%s/%s.%s", destDir, y.StreamList[0]["title"], fileext)

	log.Println("Start downloading:", filename)
	y.StartDownload(filename)
	log.Println("Finished downloading:", filename)
}