commit b60e93043b39c9412b52ed9209b5f7dc92070201
Author: Alex Grintsvayg <git@grin.io>
Date:   Tue Oct 10 22:02:16 2017 -0400

    refactor

diff --git a/video.go b/video.go
new file mode 100644
index 0000000..b7622a0
--- /dev/null
+++ b/video.go
@@ -0,0 +1,69 @@
+package ytsync
+
+import (
+	"regexp"
+	"strings"
+	"time"
+)
+
+type video struct {
+	id               string
+	channelID        string
+	channelTitle     string
+	title            string
+	description      string
+	playlistPosition int64
+	publishedAt      time.Time
+	dir              string
+}
+
+func (v video) getFilename() string {
+	return v.dir + "/" + v.id + ".mp4"
+}
+
+func (v video) getClaimName() string {
+	maxLen := 40
+	reg := regexp.MustCompile(`[^a-zA-Z0-9]+`)
+
+	chunks := strings.Split(strings.ToLower(strings.Trim(reg.ReplaceAllString(v.title, "-"), "-")), "-")
+
+	name := chunks[0]
+	if len(name) > maxLen {
+		return name[:maxLen]
+	}
+
+	for _, chunk := range chunks[1:] {
+		tmpName := name + "-" + chunk
+		if len(tmpName) > maxLen {
+			if len(name) < 20 {
+				name = tmpName[:maxLen]
+			}
+			break
+		}
+		name = tmpName
+	}
+
+	return name
+}
+
+func (v video) getAbbrevDescription() string {
+	maxLines := 10
+	description := strings.TrimSpace(v.description)
+	if strings.Count(description, "\n") < maxLines {
+		return description
+	}
+	return strings.Join(strings.Split(description, "\n")[:maxLines], "\n") + "\n..."
+}
+
+// sorting videos
+type byPublishedAt []video
+
+func (a byPublishedAt) Len() int           { return len(a) }
+func (a byPublishedAt) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+func (a byPublishedAt) Less(i, j int) bool { return a[i].publishedAt.Before(a[j].publishedAt) }
+
+type byPlaylistPosition []video
+
+func (a byPlaylistPosition) Len() int           { return len(a) }
+func (a byPlaylistPosition) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+func (a byPlaylistPosition) Less(i, j int) bool { return a[i].playlistPosition < a[j].playlistPosition }
diff --git a/ytsync.go b/ytsync.go
new file mode 100644
index 0000000..da851f1
--- /dev/null
+++ b/ytsync.go
@@ -0,0 +1,408 @@
+package ytsync
+
+import (
+	"bytes"
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"sort"
+	"strconv"
+	"strings"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/lbryio/lbry.go/jsonrpc"
+
+	"github.com/garyburd/redigo/redis"
+	"github.com/go-errors/errors"
+	ytdl "github.com/kkdai/youtube"
+	log "github.com/sirupsen/logrus"
+	"google.golang.org/api/googleapi/transport"
+	"google.golang.org/api/youtube/v3"
+)
+
+const (
+	redisHashKey   = "ytsync"
+	redisSyncedVal = "t"
+)
+
+// Sync stores the options that control how syncing happens
+type Sync struct {
+	YoutubeAPIKey    string
+	YoutubeChannelID string
+	LbryChannelName  string
+	StopOnError      bool
+	MaxTries         int
+	ConcurrentVideos int
+
+	daemon         *jsonrpc.Client
+	claimAddress   string
+	videoDirectory string
+	redisPool      *redis.Pool
+}
+
+func (s *Sync) Go() error {
+	var err error
+
+	s.redisPool = &redis.Pool{
+		MaxIdle:     3,
+		IdleTimeout: 5 * time.Minute,
+		Dial:        func() (redis.Conn, error) { return redis.Dial("tcp", ":6379") },
+		TestOnBorrow: func(c redis.Conn, t time.Time) error {
+			if time.Since(t) < time.Minute {
+				return nil
+			}
+			_, err := c.Do("PING")
+			return err
+		},
+	}
+
+	s.videoDirectory, err = ioutil.TempDir("", "ytsync")
+	if err != nil {
+		return err
+	}
+
+	s.daemon = jsonrpc.NewClient("")
+
+	addresses, err := s.daemon.WalletList()
+	if err != nil {
+		return err
+	} else if addresses == nil || len(*addresses) == 0 {
+		return errors.New("could not find an address in wallet")
+	}
+	claimAddress := (*addresses)[0]
+	if claimAddress == "" {
+		return errors.New("found blank claim address")
+	}
+
+	var wg sync.WaitGroup
+	videoQueue := make(chan video)
+
+	stopEnqueuing := make(chan struct{})
+	sendStopEnqueuing := sync.Once{}
+
+	var videoErrored atomic.Value
+	videoErrored.Store(false)
+	if s.StopOnError {
+		log.Println("Will stop publishing if an error is detected")
+	}
+
+	if s.LbryChannelName != "" {
+		err = s.ensureChannelOwnership()
+		if err != nil {
+			return err
+		}
+	}
+
+	for i := 0; i < s.ConcurrentVideos; i++ {
+		go func() {
+			wg.Add(1)
+			defer wg.Done()
+
+			for {
+				v, more := <-videoQueue
+				if !more {
+					return
+				}
+				if s.StopOnError && videoErrored.Load().(bool) {
+					log.Println("Video errored. Exiting")
+					return
+				}
+
+				tryCount := 0
+				for {
+					tryCount++
+					err := s.processVideo(v)
+
+					if err != nil {
+						log.Errorln("error processing video: " + err.Error())
+						if s.StopOnError {
+							videoErrored.Store(true)
+							sendStopEnqueuing.Do(func() {
+								stopEnqueuing <- struct{}{}
+							})
+						} else if s.MaxTries > 1 {
+							if strings.Contains(err.Error(), "non 200 status code received") ||
+								strings.Contains(err.Error(), " reason: 'This video contains content from") {
+								log.Println("This error should not be retried at all")
+							} else if tryCount >= s.MaxTries {
+								log.Println("Video failed after " + strconv.Itoa(s.MaxTries) + " retries, moving on")
+							} else {
+								log.Println("Retrying")
+								continue
+							}
+						}
+					}
+					break
+				}
+			}
+		}()
+	}
+
+	err = s.enqueueVideosFromChannel(s.YoutubeChannelID, &videoQueue, &stopEnqueuing)
+	close(videoQueue)
+	wg.Wait()
+	return err
+}
+
+func (s *Sync) ensureChannelOwnership() error {
+	channels, err := s.daemon.ChannelListMine()
+	if err != nil {
+		return err
+	} else if channels == nil {
+		return errors.New("no channels")
+	}
+
+	for _, channel := range *channels {
+		if channel.Name == s.LbryChannelName {
+			return nil
+		}
+	}
+
+	resolveResp, err := s.daemon.Resolve(s.LbryChannelName)
+	if err != nil {
+		return err
+	}
+
+	channelNotFound := (*resolveResp)[s.LbryChannelName].Error == nil || strings.Contains(*((*resolveResp)[s.LbryChannelName].Error), "cannot be resolved")
+
+	if !channelNotFound {
+		return errors.New("Channel exists and we don't own it. Pick another channel.")
+	}
+
+	_, err = s.daemon.ChannelNew(s.LbryChannelName, 0.01)
+	if err != nil {
+		return err
+	}
+
+	// niko's code says "unfortunately the queues in the daemon are not yet merged so we must give it some time for the channel to go through"
+	wait := 15 * time.Second
+	log.Println("Waiting " + wait.String() + " for channel claim to go through")
+	time.Sleep(wait)
+
+	return nil
+}
+
+func (s *Sync) enqueueVideosFromChannel(channelID string, videoChan *chan video, stopEnqueuing *chan struct{}) error {
+	client := &http.Client{
+		Transport: &transport.APIKey{Key: s.YoutubeAPIKey},
+	}
+
+	service, err := youtube.New(client)
+	if err != nil {
+		return errors.WrapPrefix(err, "error creating YouTube service", 0)
+	}
+
+	response, err := service.Channels.List("contentDetails").Id(channelID).Do()
+	if err != nil {
+		return errors.WrapPrefix(err, "error getting channels", 0)
+	}
+
+	if len(response.Items) < 1 {
+		return errors.New("youtube channel not found")
+	}
+
+	if response.Items[0].ContentDetails.RelatedPlaylists == nil {
+		return errors.New("no related playlists")
+	}
+
+	playlistID := response.Items[0].ContentDetails.RelatedPlaylists.Uploads
+	if playlistID == "" {
+		return errors.New("no channel playlist")
+	}
+
+	videos := []video{}
+
+	nextPageToken := ""
+	for {
+		req := service.PlaylistItems.List("snippet").
+			PlaylistId(playlistID).
+			MaxResults(50).
+			PageToken(nextPageToken)
+
+		playlistResponse, err := req.Do()
+		if err != nil {
+			return errors.WrapPrefix(err, "error getting playlist items", 0)
+		}
+
+		if len(playlistResponse.Items) < 1 {
+			return errors.New("playlist items not found")
+		}
+
+		for _, item := range playlistResponse.Items {
+			// todo: there's thumbnail info here. why did we need lambda???
+			publishedAt, err := time.Parse(time.RFC3339Nano, item.Snippet.PublishedAt)
+			if err != nil {
+				return errors.WrapPrefix(err, "failed to parse time", 0)
+			}
+
+			// normally we'd send the video into the channel here, but youtube api doesn't have sorting
+			// so we have to get ALL the videos, then sort them, then send them in
+			videos = append(videos, video{
+				id:               item.Snippet.ResourceId.VideoId,
+				channelID:        channelID,
+				title:            item.Snippet.Title,
+				description:      item.Snippet.Description,
+				channelTitle:     item.Snippet.ChannelTitle,
+				playlistPosition: item.Snippet.Position,
+				publishedAt:      publishedAt,
+				dir:              s.videoDirectory,
+			})
+		}
+
+		log.Infoln("Got info for " + strconv.Itoa(len(videos)) + " videos from youtube API")
+
+		nextPageToken = playlistResponse.NextPageToken
+		if nextPageToken == "" {
+			break
+		}
+	}
+
+	sort.Sort(byPublishedAt(videos))
+	//or sort.Sort(sort.Reverse(byPlaylistPosition(videos)))
+
+	for _, v := range videos {
+		select {
+		case *videoChan <- v:
+		case <-*stopEnqueuing:
+			return nil
+		}
+	}
+
+	return nil
+}
+
+func (s *Sync) processVideo(v video) error {
+	log.Println("========================================")
+	log.Println("Processing " + v.id + " (" + strconv.Itoa(int(v.playlistPosition)) + " in channel)")
+
+	conn := s.redisPool.Get()
+	defer conn.Close()
+
+	alreadyPublished, err := redis.String(conn.Do("HGET", redisHashKey, v.id))
+	if err != nil && err != redis.ErrNil {
+		return errors.WrapPrefix(err, "redis error", 0)
+
+	}
+	if alreadyPublished == redisSyncedVal {
+		log.Println(v.id + " already published")
+		return nil
+	}
+
+	//download and thumbnail can be done in parallel
+	err = downloadVideo(v)
+	if err != nil {
+		return errors.WrapPrefix(err, "download error", 0)
+	}
+
+	err = triggerThumbnailSave(v.id)
+	if err != nil {
+		return errors.WrapPrefix(err, "thumbnail error", 0)
+	}
+
+	err = s.publish(v, conn)
+	if err != nil {
+		return errors.WrapPrefix(err, "publish error", 0)
+	}
+
+	return nil
+}
+
+func downloadVideo(v video) error {
+	verbose := false
+	videoPath := v.getFilename()
+
+	_, err := os.Stat(videoPath)
+	if err != nil && !os.IsNotExist(err) {
+		return err
+	} else if err == nil {
+		log.Println(v.id + " already exists at " + videoPath)
+		return nil
+	}
+
+	downloader := ytdl.NewYoutube(verbose)
+	err = downloader.DecodeURL("https://www.youtube.com/watch?v=" + v.id)
+	if err != nil {
+		return err
+	}
+	err = downloader.StartDownload(videoPath)
+	if err != nil {
+		return err
+	}
+	log.Debugln("Downloaded " + v.id)
+	return nil
+}
+
+func triggerThumbnailSave(videoID string) error {
+	client := &http.Client{Timeout: 30 * time.Second}
+
+	params, err := json.Marshal(map[string]string{"videoid": videoID})
+	if err != nil {
+		return err
+	}
+
+	request, err := http.NewRequest(http.MethodPut, "https://jgp4g1qoud.execute-api.us-east-1.amazonaws.com/prod/thumbnail", bytes.NewBuffer(params))
+	if err != nil {
+		return err
+	}
+
+	response, err := client.Do(request)
+	if err != nil {
+		return err
+	}
+	defer response.Body.Close()
+
+	contents, err := ioutil.ReadAll(response.Body)
+	if err != nil {
+		return err
+	}
+
+	var decoded struct {
+		error   int    `json:"error"`
+		url     string `json:"url,omitempty"`
+		message string `json:"message,omitempty"`
+	}
+	err = json.Unmarshal(contents, &decoded)
+	if err != nil {
+		return err
+	}
+
+	if decoded.error != 0 {
+		return errors.New("error creating thumbnail: " + decoded.message)
+	}
+
+	log.Debugln("Created thumbnail for " + videoID)
+
+	return nil
+}
+
+func strPtr(s string) *string { return &s }
+
+func (s *Sync) publish(v video, conn redis.Conn) error {
+	options := jsonrpc.PublishOptions{
+		Title:        &v.title,
+		Author:       &v.channelTitle,
+		Description:  strPtr(v.getAbbrevDescription() + "\nhttps://www.youtube.com/watch?v=" + v.id),
+		Language:     strPtr("en"),
+		ClaimAddress: &s.claimAddress,
+		Thumbnail:    strPtr("http://berk.ninja/thumbnails/" + v.id),
+		License:      strPtr("Copyrighted (contact author)"),
+	}
+	if s.LbryChannelName != "" {
+		options.ChannelName = &s.LbryChannelName
+	}
+
+	_, err := s.daemon.Publish(v.getClaimName(), v.getFilename(), 0.01, options)
+	if err != nil {
+		return err
+	}
+
+	_, err = redis.Bool(conn.Do("HSET", redisHashKey, v.id, redisSyncedVal))
+	if err != nil {
+		return errors.New("redis error: " + err.Error())
+	}
+
+	return nil
+}