ytsync/manager/ytsync.go

package manager

import (
	"fmt"
	"io/ioutil"
	"net/http"
	"os"
	"os/signal"
	"runtime/debug"
	"sort"
	"strconv"
	"strings"
	"sync"
	"syscall"
	"time"

	"github.com/lbryio/ytsync/namer"
	"github.com/lbryio/ytsync/sdk"
	"github.com/lbryio/ytsync/sources"
	"github.com/lbryio/ytsync/thumbs"
	logUtils "github.com/lbryio/ytsync/util"

	"github.com/lbryio/lbry.go/v2/extras/errors"
	"github.com/lbryio/lbry.go/v2/extras/jsonrpc"
	"github.com/lbryio/lbry.go/v2/extras/stop"
	"github.com/lbryio/lbry.go/v2/extras/util"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/awserr"
	"github.com/aws/aws-sdk-go/aws/credentials"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/aws/aws-sdk-go/service/s3"
	"github.com/aws/aws-sdk-go/service/s3/s3manager"
	log "github.com/sirupsen/logrus"
	"google.golang.org/api/googleapi/transport"
	"google.golang.org/api/youtube/v3"
)

const (
	channelClaimAmount    = 0.01
	estimatedMaxTxFee     = 0.1
	minimumAccountBalance = 1.0
	minimumRefillAmount   = 1
	publishAmount         = 0.01
	maxReasonLength       = 500
)

type video interface {
	Size() *int64
	ID() string
	IDAndNum() string
	PlaylistPosition() int
	PublishedAt() time.Time
	Sync(*jsonrpc.Client, sources.SyncParams, *sdk.SyncedVideo, bool, *sync.RWMutex) (*sources.SyncSummary, error)
}

// 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()) }

// Sync stores the options that control how syncing happens
type Sync struct {
	APIConfig            *sdk.APIConfig
	YoutubeChannelID     string
	LbryChannelName      string
	MaxTries             int
	ConcurrentVideos     int
	Refill               int
	Manager              *SyncManager
	LbrycrdString        string
	AwsS3ID              string
	AwsS3Secret          string
	AwsS3Region          string
	AwsS3Bucket          string
	Fee                  *sdk.Fee
	daemon               *jsonrpc.Client
	claimAddress         string
	videoDirectory       string
	syncedVideosMux      *sync.RWMutex
	syncedVideos         map[string]sdk.SyncedVideo
	grp                  *stop.Group
	lbryChannelID        string
	namer                *namer.Namer
	walletMux            *sync.RWMutex
	queue                chan video
	transferState        int
	clientPublishAddress string
	publicKey            string
	defaultAccountID     string
}

func (s *Sync) AppendSyncedVideo(videoID string, published bool, failureReason string, claimName string, claimID string, metadataVersion int8, size int64) {
	s.syncedVideosMux.Lock()
	defer s.syncedVideosMux.Unlock()
	s.syncedVideos[videoID] = sdk.SyncedVideo{
		VideoID:         videoID,
		Published:       published,
		FailureReason:   failureReason,
		ClaimID:         claimID,
		ClaimName:       claimName,
		MetadataVersion: metadataVersion,
		Size:            size,
	}
}

// IsInterrupted can be queried to discover if the sync process was interrupted manually
func (s *Sync) IsInterrupted() bool {
	select {
	case <-s.grp.Ch():
		return true
	default:
		return false
	}
}

func (s *Sync) downloadWallet() error {
	defaultWalletDir, defaultTempWalletDir, key, err := s.getWalletPaths()
	if err != nil {
		return errors.Err(err)
	}

	creds := credentials.NewStaticCredentials(s.AwsS3ID, s.AwsS3Secret, "")
	s3Session, err := session.NewSession(&aws.Config{Region: aws.String(s.AwsS3Region), Credentials: creds})
	if err != nil {
		return errors.Prefix("error starting session: ", err)
	}
	downloader := s3manager.NewDownloader(s3Session)
	out, err := os.Create(defaultTempWalletDir)
	if err != nil {
		return errors.Prefix("error creating temp wallet: ", err)
	}
	defer out.Close()

	bytesWritten, err := downloader.Download(out, &s3.GetObjectInput{
		Bucket: aws.String(s.AwsS3Bucket),
		Key:    key,
	})
	if err != nil {
		// Casting to the awserr.Error type will allow you to inspect the error
		// code returned by the service in code. The error code can be used
		// to switch on context specific functionality. In this case a context
		// specific error message is printed to the user based on the bucket
		// and key existing.
		//
		// For information on other S3 API error codes see:
		// http://docs.aws.amazon.com/AmazonS3/latest/API/ErrorResponses.html
		if aerr, ok := err.(awserr.Error); ok {
			code := aerr.Code()
			if code == s3.ErrCodeNoSuchKey {
				return errors.Err("wallet not on S3")
			}
		}
		return err
	} else if bytesWritten == 0 {
		return errors.Err("zero bytes written")
	}

	err = os.Rename(defaultTempWalletDir, defaultWalletDir)
	if err != nil {
		return errors.Prefix("error replacing temp wallet for default wallet: ", err)
	}

	return nil
}

func (s *Sync) getWalletPaths() (defaultWallet, tempWallet string, key *string, err error) {

	defaultWallet = os.Getenv("HOME") + "/.lbryum/wallets/default_wallet"
	tempWallet = os.Getenv("HOME") + "/.lbryum/wallets/tmp_wallet"
	key = aws.String("/wallets/" + s.YoutubeChannelID)
	if logUtils.IsRegTest() {
		defaultWallet = os.Getenv("HOME") + "/.lbryum_regtest/wallets/default_wallet"
		tempWallet = os.Getenv("HOME") + "/.lbryum_regtest/wallets/tmp_wallet"
		key = aws.String("/regtest/" + s.YoutubeChannelID)
	}

	walletPath := os.Getenv("LBRYNET_WALLETS_DIR")
	if walletPath != "" {
		defaultWallet = walletPath + "/wallets/default_wallet"
		tempWallet = walletPath + "/wallets/tmp_wallet"
	}

	if _, err := os.Stat(defaultWallet); !os.IsNotExist(err) {
		return "", "", nil, errors.Err("default_wallet already exists")
	}
	return
}

func (s *Sync) uploadWallet() error {
	defaultWalletDir := logUtils.GetDefaultWalletPath()
	key := aws.String("/wallets/" + s.YoutubeChannelID)
	if logUtils.IsRegTest() {
		key = aws.String("/regtest/" + s.YoutubeChannelID)
	}

	if _, err := os.Stat(defaultWalletDir); os.IsNotExist(err) {
		return errors.Err("default_wallet does not exist")
	}

	creds := credentials.NewStaticCredentials(s.AwsS3ID, s.AwsS3Secret, "")
	s3Session, err := session.NewSession(&aws.Config{Region: aws.String(s.AwsS3Region), Credentials: creds})
	if err != nil {
		return err
	}

	uploader := s3manager.NewUploader(s3Session)

	file, err := os.Open(defaultWalletDir)
	if err != nil {
		return err
	}
	defer file.Close()

	_, err = uploader.Upload(&s3manager.UploadInput{
		Bucket: aws.String(s.AwsS3Bucket),
		Key:    key,
		Body:   file,
	})
	if err != nil {
		return err
	}

	return os.Remove(defaultWalletDir)
}

func (s *Sync) setStatusSyncing() error {
	syncedVideos, claimNames, err := s.Manager.apiConfig.SetChannelStatus(s.YoutubeChannelID, StatusSyncing, "", nil)
	if err != nil {
		return err
	}
	s.syncedVideosMux.Lock()
	s.syncedVideos = syncedVideos
	s.namer.SetNames(claimNames)
	s.syncedVideosMux.Unlock()
	return nil
}

func (s *Sync) setExceptions() {
	if s.YoutubeChannelID == "UCwjQfNRW6sGYb__pd7d4nUg" { //@FreeTalkLive
		s.Manager.maxVideoLength = 0.0 // skips max length checks
		s.Manager.maxVideoSize = 0
	}
}

func (s *Sync) FullCycle() (e error) {
	if os.Getenv("HOME") == "" {
		return errors.Err("no $HOME env var found")
	}
	if s.YoutubeChannelID == "" {
		return errors.Err("channel ID not provided")
	}

	s.setExceptions()

	s.syncedVideosMux = &sync.RWMutex{}
	s.walletMux = &sync.RWMutex{}
	s.grp = stop.New()
	s.queue = make(chan video)
	interruptChan := make(chan os.Signal, 1)
	signal.Notify(interruptChan, os.Interrupt, syscall.SIGTERM)
	defer signal.Stop(interruptChan)
	go func() {
		<-interruptChan
		log.Println("Got interrupt signal, shutting down (if publishing, will shut down after current publish)")
		s.grp.Stop()
	}()
	err := s.setStatusSyncing()
	if err != nil {
		return err
	}

	defer s.setChannelTerminationStatus(&e)

	err = s.downloadWallet()
	if err != nil && err.Error() != "wallet not on S3" {
		return errors.Prefix("failure in downloading wallet", err)
	} else if err == nil {
		log.Println("Continuing previous upload")
	} else {
		log.Println("Starting new wallet")
	}

	defer s.stopAndUploadWallet(&e)

	s.videoDirectory, err = ioutil.TempDir(os.Getenv("TMP_DIR"), "ytsync")
	if err != nil {
		return errors.Wrap(err, 0)
	}
	err = os.Chmod(s.videoDirectory, 0766)
	if err != nil {
		return errors.Err(err)
	}

	defer deleteSyncFolder(s.videoDirectory)
	log.Printf("Starting daemon")
	err = logUtils.StartDaemon()
	if err != nil {
		return err
	}

	log.Infoln("Waiting for daemon to finish starting...")
	s.daemon = jsonrpc.NewClient(os.Getenv("LBRYNET_ADDRESS"))
	s.daemon.SetRPCTimeout(40 * time.Minute)

	err = s.waitForDaemonStart()
	if err != nil {
		return err
	}

	err = s.doSync()
	if err != nil {
		return err
	}

	if s.shouldTransfer() {
		return s.processTransfers()
	}

	return nil
}

func (s *Sync) processTransfers() (e error) {
	log.Println("Processing transfers")
	err := waitConfirmations(s)
	if err != nil {
		return err
	}
	supportAmount, err := abandonSupports(s)
	if err != nil {
		return errors.Prefix(fmt.Sprintf("%.6f LBCs were abandoned before failing", supportAmount), err)
	}
	if supportAmount > 0 {
		logUtils.SendInfoToSlack("%.6f LBCs were abandoned and should be used as support", supportAmount)
	}
	err = transferVideos(s)
	if err != nil {
		return err
	}
	err = transferChannel(s)
	if err != nil {
		return err
	}
	defaultAccount, err := s.getDefaultAccount()
	if err != nil {
		return err
	}
	reallocateSupports := supportAmount > 0.01
	if reallocateSupports {
		err = waitConfirmations(s)
		if err != nil {
			return err
		}
		isTip := true
		summary, err := s.daemon.SupportCreate(s.lbryChannelID, fmt.Sprintf("%.6f", supportAmount), &isTip, nil, []string{defaultAccount})
		if err != nil {
			return errors.Err(err)
		}
		if len(summary.Outputs) < 1 {
			return errors.Err("something went wrong while tipping the channel for %.6f LBCs", supportAmount)
		}
	}
	log.Println("Done processing transfers")
	return nil
}

func deleteSyncFolder(videoDirectory string) {
	if !strings.Contains(videoDirectory, "/tmp/ytsync") {
		_ = util.SendToSlack(errors.Err("Trying to delete an unexpected directory: %s", videoDirectory).Error())
	}
	err := os.RemoveAll(videoDirectory)
	if err != nil {
		_ = util.SendToSlack(err.Error())
	}
}

func (s *Sync) shouldTransfer() bool {
	return s.transferState >= 1 && s.clientPublishAddress != "" && !s.Manager.SyncFlags.DisableTransfers
}

func (s *Sync) setChannelTerminationStatus(e *error) {
	var transferState *int

	if s.shouldTransfer() {
		if *e == nil {
			transferState = util.PtrToInt(TransferStateComplete)
		}
	}
	if *e != nil {
		//conditions for which a channel shouldn't be marked as failed
		noFailConditions := []string{
			"this youtube channel is being managed by another server",
			"interrupted during daemon startup",
		}
		if util.SubstringInSlice((*e).Error(), noFailConditions) {
			return
		}
		failureReason := (*e).Error()
		_, _, err := s.Manager.apiConfig.SetChannelStatus(s.YoutubeChannelID, StatusFailed, failureReason, transferState)
		if err != nil {
			msg := fmt.Sprintf("Failed setting failed state for channel %s", s.LbryChannelName)
			*e = errors.Prefix(msg+err.Error(), *e)
		}
	} else if !s.IsInterrupted() {
		_, _, err := s.Manager.apiConfig.SetChannelStatus(s.YoutubeChannelID, StatusSynced, "", transferState)
		if err != nil {
			*e = err
		}
	}
}

func (s *Sync) waitForDaemonStart() error {
	beginTime := time.Now()
	for {
		select {
		case <-s.grp.Ch():
			return errors.Err("interrupted during daemon startup")
		default:
			status, err := s.daemon.Status()
			if err == nil && status.StartupStatus.Wallet && status.IsRunning {
				return nil
			}
			if time.Since(beginTime).Minutes() > 60 {
				s.grp.Stop()
				return errors.Err("the daemon is taking too long to start. Something is wrong")
			}
			time.Sleep(5 * time.Second)
		}
	}
}

func (s *Sync) stopAndUploadWallet(e *error) {
	log.Printf("Stopping daemon")
	shutdownErr := logUtils.StopDaemon()
	if shutdownErr != nil {
		logShutdownError(shutdownErr)
	} else {
		// the cli will return long before the daemon effectively stops. we must observe the processes running
		// before moving the wallet
		waitTimeout := 8 * time.Minute
		processDeathError := waitForDaemonProcess(waitTimeout)
		if processDeathError != nil {
			logShutdownError(processDeathError)
		} else {
			err := s.uploadWallet()
			if err != nil {
				if *e == nil {
					e = &err
					return
				} else {
					*e = errors.Prefix("failure uploading wallet", *e)
				}
			}
		}
	}
}
func logShutdownError(shutdownErr error) {
	logUtils.SendErrorToSlack("error shutting down daemon: %s", errors.FullTrace(shutdownErr))
	logUtils.SendErrorToSlack("WALLET HAS NOT BEEN MOVED TO THE WALLET BACKUP DIR")
}

var thumbnailHosts = []string{
	"berk.ninja/thumbnails/",
	thumbs.ThumbnailEndpoint,
}

func isYtsyncClaim(c jsonrpc.Claim) bool {
	if !util.InSlice(c.Type, []string{"claim", "update"}) || c.Value.GetStream() == nil {
		return false
	}
	if c.Value.GetThumbnail() == nil || c.Value.GetThumbnail().GetUrl() == "" {
		//most likely a claim created outside of ytsync, ignore!
		return false
	}

	for _, th := range thumbnailHosts {
		if strings.Contains(c.Value.GetThumbnail().GetUrl(), th) {
			return true
		}
	}
	return false
}

// fixDupes abandons duplicate claims
func (s *Sync) fixDupes(claims []jsonrpc.Claim) (bool, error) {
	abandonedClaims := false
	videoIDs := make(map[string]jsonrpc.Claim)
	for _, c := range claims {
		if !isYtsyncClaim(c) {
			continue
		}
		tn := c.Value.GetThumbnail().GetUrl()
		videoID := tn[strings.LastIndex(tn, "/")+1:]

		cl, ok := videoIDs[videoID]
		if !ok || cl.ClaimID == c.ClaimID {
			videoIDs[videoID] = c
			continue
		}
		// only keep the most recent one
		claimToAbandon := c
		videoIDs[videoID] = cl
		if c.Height > cl.Height {
			claimToAbandon = cl
			videoIDs[videoID] = c
		}
		if claimToAbandon.Address != s.clientPublishAddress && !s.syncedVideos[videoID].Transferred {
			log.Debugf("abandoning %+v", claimToAbandon)
			_, err := s.daemon.StreamAbandon(claimToAbandon.Txid, claimToAbandon.Nout, nil, false)
			if err != nil {
				return true, err
			}
		} else {
			log.Debugf("lbrynet stream abandon --txid=%s --nout=%d", claimToAbandon.Txid, claimToAbandon.Nout)
		}
		abandonedClaims = true
		//return true, nil
	}
	return abandonedClaims, nil
}

type ytsyncClaim struct {
	ClaimID         string
	MetadataVersion uint
	ClaimName       string
	PublishAddress  string
	VideoID         string
	Claim           *jsonrpc.Claim
}

// mapFromClaims returns a map of videoIDs (youtube id) to ytsyncClaim which is a structure holding blockchain related
// information
func (s *Sync) mapFromClaims(claims []jsonrpc.Claim) map[string]ytsyncClaim {
	videoIDMap := make(map[string]ytsyncClaim, len(claims))
	for _, c := range claims {
		if !isYtsyncClaim(c) {
			continue
		}
		tn := c.Value.GetThumbnail().GetUrl()
		videoID := tn[strings.LastIndex(tn, "/")+1:]
		claimMetadataVersion := uint(1)
		if strings.Contains(tn, thumbs.ThumbnailEndpoint) {
			claimMetadataVersion = 2
		}

		videoIDMap[videoID] = ytsyncClaim{
			ClaimID:         c.ClaimID,
			MetadataVersion: claimMetadataVersion,
			ClaimName:       c.Name,
			PublishAddress:  c.Address,
			VideoID:         videoID,
			Claim:           &c,
		}
	}
	return videoIDMap
}

//updateRemoteDB counts the amount of videos published so far and updates the remote db if some videos weren't marked as published
//additionally it removes all entries in the database indicating that a video is published when it's actually not
func (s *Sync) updateRemoteDB(claims []jsonrpc.Claim, ownClaims []jsonrpc.Claim) (total, fixed, removed int, err error) {
	allClaimsInfo := s.mapFromClaims(claims)
	ownClaimsInfo := s.mapFromClaims(ownClaims)
	count := len(allClaimsInfo)
	idsToRemove := make([]string, 0, count)

	for videoID, chainInfo := range allClaimsInfo {
		s.syncedVideosMux.RLock()
		sv, claimInDatabase := s.syncedVideos[videoID]
		s.syncedVideosMux.RUnlock()

		metadataDiffers := claimInDatabase && sv.MetadataVersion != int8(chainInfo.MetadataVersion)
		claimIDDiffers := claimInDatabase && sv.ClaimID != chainInfo.ClaimID
		claimNameDiffers := claimInDatabase && sv.ClaimName != chainInfo.ClaimName
		claimMarkedUnpublished := claimInDatabase && !sv.Published
		_, isOwnClaim := ownClaimsInfo[videoID]
		tranferred := !isOwnClaim
		transferStatusMismatch := sv.Transferred != tranferred

		if metadataDiffers {
			log.Debugf("%s: Mismatch in database for metadata. DB: %d - Blockchain: %d", videoID, sv.MetadataVersion, chainInfo.MetadataVersion)
		}
		if claimIDDiffers {
			log.Debugf("%s: Mismatch in database for claimID. DB: %s - Blockchain: %s", videoID, sv.ClaimID, chainInfo.ClaimID)
		}
		if claimNameDiffers {
			log.Debugf("%s: Mismatch in database for claimName. DB: %s - Blockchain: %s", videoID, sv.ClaimName, chainInfo.ClaimName)
		}
		if claimMarkedUnpublished {
			log.Debugf("%s: Mismatch in database: published but marked as unpublished", videoID)
		}
		if !claimInDatabase {
			log.Debugf("%s: Published but is not in database (%s - %s)", videoID, chainInfo.ClaimName, chainInfo.ClaimID)
		}
		if transferStatusMismatch {
			log.Debugf("%s: is marked as transferred %t on it's actually %t", videoID, sv.Transferred, tranferred)
		}

		if !claimInDatabase || metadataDiffers || claimIDDiffers || claimNameDiffers || claimMarkedUnpublished || transferStatusMismatch {
			claimSize, err := chainInfo.Claim.GetStreamSizeByMagic()
			if err != nil {
				claimSize = 0
			}
			fixed++
			log.Debugf("updating %s in the database", videoID)
			err = s.Manager.apiConfig.MarkVideoStatus(sdk.VideoStatus{
				ChannelID:       s.YoutubeChannelID,
				VideoID:         videoID,
				Status:          VideoStatusPublished,
				ClaimID:         chainInfo.ClaimID,
				ClaimName:       chainInfo.ClaimName,
				Size:            util.PtrToInt64(int64(claimSize)),
				MetaDataVersion: chainInfo.MetadataVersion,
				IsTransferred:   &tranferred,
			})
			if err != nil {
				return count, fixed, 0, err
			}
		}
	}

	//reload the synced videos map before we use it for further processing
	if fixed > 0 {
		err := s.setStatusSyncing()
		if err != nil {
			return count, fixed, 0, err
		}
	}

	for vID, sv := range s.syncedVideos {
		if sv.Transferred {
			_, ok := allClaimsInfo[vID]
			if !ok && sv.Published {
				log.Warnf("%s: claims to be published and transferred but wasn't found in the list of claims", vID)
				idsToRemove = append(idsToRemove, vID)
			}
			continue
		}
		_, ok := ownClaimsInfo[vID]
		if !ok && sv.Published {
			log.Debugf("%s: claims to be published but wasn't found in the list of claims and will be removed if --remove-db-unpublished was specified (%t)", vID, s.Manager.SyncFlags.RemoveDBUnpublished)
			idsToRemove = append(idsToRemove, vID)
		}
	}
	if s.Manager.SyncFlags.RemoveDBUnpublished && len(idsToRemove) > 0 {
		log.Infof("removing: %s", strings.Join(idsToRemove, ","))
		err := s.Manager.apiConfig.DeleteVideos(idsToRemove)
		if err != nil {
			return count, fixed, len(idsToRemove), err
		}
		removed++
	}
	//reload the synced videos map before we use it for further processing
	if removed > 0 {
		err := s.setStatusSyncing()
		if err != nil {
			return count, fixed, removed, err
		}
	}
	return count, fixed, removed, nil
}

func (s *Sync) getClaims(defaultOnly bool) ([]jsonrpc.Claim, error) {
	var account *string = nil
	if defaultOnly {
		a, err := s.getDefaultAccount()
		if err != nil {
			return nil, err
		}
		account = &a
	}
	claims, err := s.daemon.StreamList(account)
	if err != nil {
		return nil, errors.Prefix("cannot list claims", err)
	}

	return *claims, nil
}

func (s *Sync) checkIntegrity() error {
	allClaims, err := s.getClaims(false)
	if err != nil {
		return err
	}
	hasDupes, err := s.fixDupes(allClaims)
	if err != nil {
		return errors.Prefix("error checking for duplicates", err)
	}
	if hasDupes {
		logUtils.SendInfoToSlack("Channel had dupes and was fixed!")
		err = s.waitForNewBlock()
		if err != nil {
			return err
		}
		allClaims, err = s.getClaims(false)
		if err != nil {
			return err
		}
	}

	ownClaims, err := s.getClaims(true)
	if err != nil {
		return err
	}
	pubsOnWallet, nFixed, nRemoved, err := s.updateRemoteDB(allClaims, ownClaims)
	if err != nil {
		return errors.Prefix("error updating remote database", err)
	}

	if nFixed > 0 || nRemoved > 0 {
		if nFixed > 0 {
			logUtils.SendInfoToSlack("%d claims had mismatched database info or were completely missing and were fixed", nFixed)
		}
		if nRemoved > 0 {
			logUtils.SendInfoToSlack("%d were marked as published but weren't actually published and thus removed from the database", nRemoved)
		}
	}
	pubsOnDB := 0
	for _, sv := range s.syncedVideos {
		if sv.Published {
			pubsOnDB++
		}
	}

	if pubsOnWallet > pubsOnDB { //This case should never happen
		logUtils.SendInfoToSlack("We're claiming to have published %d videos but in reality we published %d (%s)", pubsOnDB, pubsOnWallet, s.YoutubeChannelID)
		return errors.Err("not all published videos are in the database")
	}
	if pubsOnWallet < pubsOnDB {
		logUtils.SendInfoToSlack("we're claiming to have published %d videos but we only published %d (%s)", pubsOnDB, pubsOnWallet, s.YoutubeChannelID)
	}

	_, err = s.getUnsentSupports() //TODO: use the returned value when it works
	if err != nil {
		return err
	}
	return nil
}

func (s *Sync) doSync() error {
	err := s.enableAddressReuse()
	if err != nil {
		return errors.Prefix("could not set address reuse policy", err)
	}
	err = s.importPublicKey()
	if err != nil {
		return errors.Prefix("could not import the transferee public key", err)
	}
	err = s.walletSetup()
	if err != nil {
		return errors.Prefix("Initial wallet setup failed! Manual Intervention is required.", err)
	}

	err = s.checkIntegrity()
	if err != nil {
		return err
	}

	if s.transferState != TransferStateComplete {
		cert, err := s.daemon.ChannelExport(s.lbryChannelID, nil, nil)
		if err != nil {
			return errors.Prefix("error getting channel cert", err)
		}
		if cert != nil {
			err = s.APIConfig.SetChannelCert(string(*cert), s.lbryChannelID)
			if err != nil {
				return errors.Prefix("error setting channel cert", err)
			}
		}
	}

	if s.Manager.SyncFlags.StopOnError {
		log.Println("Will stop publishing if an error is detected")
	}

	for i := 0; i < s.ConcurrentVideos; i++ {
		s.grp.Add(1)
		go func(i int) {
			defer s.grp.Done()
			s.startWorker(i)
		}(i)
	}

	if s.LbryChannelName == "@UCBerkeley" {
		err = errors.Err("UCB is not supported in this version of YTSYNC")
	} else {
		err = s.enqueueYoutubeVideos()
	}
	close(s.queue)
	s.grp.Wait()
	return err
}

func (s *Sync) startWorker(workerNum int) {
	var v video
	var more bool

	for {
		select {
		case <-s.grp.Ch():
			log.Printf("Stopping worker %d", workerNum)
			return
		default:
		}

		select {
		case v, more = <-s.queue:
			if !more {
				return
			}
		case <-s.grp.Ch():
			log.Printf("Stopping worker %d", workerNum)
			return
		}

		log.Println("================================================================================")

		tryCount := 0
		for {
			tryCount++
			err := s.processVideo(v)

			if err != nil {
				logMsg := fmt.Sprintf("error processing video %s: %s", v.ID(), err.Error())
				log.Errorln(logMsg)
				if strings.Contains(strings.ToLower(err.Error()), "interrupted by user") {
					return
				}
				fatalErrors := []string{
					":5279: read: connection reset by peer",
					"no space left on device",
					"NotEnoughFunds",
					"Cannot publish using channel",
					"cannot concatenate 'str' and 'NoneType' objects",
					"more than 90% of the space has been used.",
					"Couldn't find private key for id",
					"You already have a stream claim published under the name",
				}
				if util.SubstringInSlice(err.Error(), fatalErrors) || s.Manager.SyncFlags.StopOnError {
					s.grp.Stop()
				} else if s.MaxTries > 1 {
					errorsNoRetry := []string{
						"non 200 status code received",
						"This video contains content from",
						"dont know which claim to update",
						"uploader has not made this video available in your country",
						"download error: AccessDenied: Access Denied",
						"Playback on other websites has been disabled by the video owner",
						"Error in daemon: Cannot publish empty file",
						"Error extracting sts from embedded url response",
						"Unable to extract signature tokens",
						"Client.Timeout exceeded while awaiting headers",
						"the video is too big to sync, skipping for now",
						"video is too long to process",
						"no compatible format available for this video",
						"Watch this video on YouTube.",
						"have blocked it on copyright grounds",
						"the video must be republished as we can't get the right size",
						"HTTP Error 403",
						"giving up after 0 fragment retries",
						"Sorry about that",
						"This video is not available",
					}
					if util.SubstringInSlice(err.Error(), errorsNoRetry) {
						log.Println("This error should not be retried at all")
					} else if tryCount < s.MaxTries {
						if strings.Contains(err.Error(), "txn-mempool-conflict") ||
							strings.Contains(err.Error(), "too-long-mempool-chain") {
							log.Println("waiting for a block before retrying")
							err := s.waitForNewBlock()
							if err != nil {
								s.grp.Stop()
								logUtils.SendErrorToSlack("something went wrong while waiting for a block: %s", errors.FullTrace(err))
								break
							}
						} else if util.SubstringInSlice(err.Error(), []string{
							"Not enough funds to cover this transaction",
							"failed: Not enough funds",
							"Error in daemon: Insufficient funds, please deposit additional LBC",
						}) {
							log.Println("checking funds and UTXOs before retrying...")
							err := s.walletSetup()
							if err != nil {
								s.grp.Stop()
								logUtils.SendErrorToSlack("failed to setup the wallet for a refill: %s", errors.FullTrace(err))
								break
							}
						} else if strings.Contains(err.Error(), "Error in daemon: 'str' object has no attribute 'get'") {
							time.Sleep(5 * time.Second)
						}
						log.Println("Retrying")
						continue
					}
					logUtils.SendErrorToSlack("Video failed after %d retries, skipping. Stack: %s", tryCount, logMsg)
				}
				s.syncedVideosMux.RLock()
				existingClaim, ok := s.syncedVideos[v.ID()]
				s.syncedVideosMux.RUnlock()
				existingClaimID := ""
				existingClaimName := ""
				existingClaimSize := int64(0)
				if v.Size() != nil {
					existingClaimSize = *v.Size()
				}
				if ok {
					existingClaimID = existingClaim.ClaimID
					existingClaimName = existingClaim.ClaimName
					if existingClaim.Size > 0 {
						existingClaimSize = existingClaim.Size
					}
				}
				videoStatus := VideoStatusFailed
				if strings.Contains(err.Error(), "upgrade failed") {
					videoStatus = VideoStatusUpgradeFailed
				} else {
					s.AppendSyncedVideo(v.ID(), false, err.Error(), existingClaimName, existingClaimID, 0, existingClaimSize)
				}
				err = s.Manager.apiConfig.MarkVideoStatus(sdk.VideoStatus{
					ChannelID:     s.YoutubeChannelID,
					VideoID:       v.ID(),
					Status:        videoStatus,
					ClaimID:       existingClaimID,
					ClaimName:     existingClaimName,
					FailureReason: err.Error(),
					Size:          &existingClaimSize,
				})
				if err != nil {
					logUtils.SendErrorToSlack("Failed to mark video on the database: %s", errors.FullTrace(err))
				}
			}
			break
		}
	}
}

func (s *Sync) enqueueYoutubeVideos() error {
	client := &http.Client{
		Transport: &transport.APIKey{Key: s.APIConfig.YoutubeAPIKey},
	}

	service, err := youtube.New(client)
	if err != nil {
		return errors.Prefix("error creating YouTube service", err)
	}

	response, err := service.Channels.List("contentDetails").Id(s.YoutubeChannelID).Do()
	if err != nil {
		return errors.Prefix("error getting channels", err)
	}

	if len(response.Items) < 1 {
		return errors.Err("youtube channel not found")
	}

	if response.Items[0].ContentDetails.RelatedPlaylists == nil {
		return errors.Err("no related playlists")
	}

	playlistID := response.Items[0].ContentDetails.RelatedPlaylists.Uploads
	if playlistID == "" {
		return errors.Err("no channel playlist")
	}

	var videos []video
	playlistMap := make(map[string]*youtube.PlaylistItemSnippet, 50)
	nextPageToken := ""
	for {
		req := service.PlaylistItems.List("snippet").
			PlaylistId(playlistID).
			MaxResults(50).
			PageToken(nextPageToken)

		playlistResponse, err := req.Do()
		if err != nil {
			return errors.Prefix("error getting playlist items", err)
		}

		if len(playlistResponse.Items) < 1 {
			// If there are 50+ videos in a playlist but less than 50 are actually returned by the API, youtube will still redirect
			// clients to a next page. Such next page will however be empty. This logic prevents ytsync from failing.
			youtubeIsLying := len(videos) > 0
			if youtubeIsLying {
				break
			}
			return errors.Err("playlist items not found")
		}
		//playlistMap := make(map[string]*youtube.PlaylistItemSnippet, 50)
		videoIDs := make([]string, 50)
		for i, item := range playlistResponse.Items {
			// 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
			playlistMap[item.Snippet.ResourceId.VideoId] = item.Snippet
			videoIDs[i] = item.Snippet.ResourceId.VideoId
		}
		req2 := service.Videos.List("snippet,contentDetails,recordingDetails").Id(strings.Join(videoIDs[:], ","))

		videosListResponse, err := req2.Do()
		if err != nil {
			return errors.Prefix("error getting videos info", err)
		}
		for _, item := range videosListResponse.Items {
			videos = append(videos, sources.NewYoutubeVideo(s.videoDirectory, item, playlistMap[item.Id].Position, s.Manager.GetS3AWSConfig(), s.grp))
		}

		log.Infof("Got info for %d videos from youtube API", len(videos))

		nextPageToken = playlistResponse.NextPageToken
		if nextPageToken == "" {
			break
		}
	}
	for k, v := range s.syncedVideos {
		if !v.Published {
			continue
		}
		_, ok := playlistMap[k]
		if !ok {
			videos = append(videos, sources.NewMockedVideo(s.videoDirectory, k, s.YoutubeChannelID, s.Manager.GetS3AWSConfig(), s.grp))
		}

	}
	sort.Sort(byPublishedAt(videos))
	//or sort.Sort(sort.Reverse(byPlaylistPosition(videos)))

Enqueue:
	for _, v := range videos {
		select {
		case <-s.grp.Ch():
			break Enqueue
		default:
		}

		select {
		case s.queue <- v:
		case <-s.grp.Ch():
			break Enqueue
		}
	}

	return nil
}

func (s *Sync) processVideo(v video) (err error) {
	defer func() {
		if p := recover(); p != nil {
			log.Printf("stack: %s", debug.Stack())
			var ok bool
			err, ok = p.(error)
			if !ok {
				err = errors.Err("%v", p)
			}
			err = errors.Wrap(p, 2)
		}
	}()

	log.Println("Processing " + v.IDAndNum())
	defer func(start time.Time) {
		log.Println(v.ID() + " took " + time.Since(start).String())
	}(time.Now())

	s.syncedVideosMux.RLock()
	sv, ok := s.syncedVideos[v.ID()]
	s.syncedVideosMux.RUnlock()
	newMetadataVersion := int8(2)
	alreadyPublished := ok && sv.Published
	videoRequiresUpgrade := ok && s.Manager.SyncFlags.UpgradeMetadata && sv.MetadataVersion < newMetadataVersion

	neverRetryFailures := []string{
		"Error extracting sts from embedded url response",
		"Unable to extract signature tokens",
		"the video is too big to sync, skipping for now",
		"video is too long to process",
		"This video contains content from",
		"no compatible format available for this video",
		"Watch this video on YouTube.",
		"have blocked it on copyright grounds",
		"giving up after 0 fragment retries",
	}
	if ok && !sv.Published && util.SubstringInSlice(sv.FailureReason, neverRetryFailures) {
		log.Println(v.ID() + " can't ever be published")
		return nil
	}

	if alreadyPublished && !videoRequiresUpgrade {
		log.Println(v.ID() + " already published")
		return nil
	}
	if ok && sv.MetadataVersion >= newMetadataVersion {
		log.Println(v.ID() + " upgraded to the new metadata")
		return nil
	}

	if !videoRequiresUpgrade && v.PlaylistPosition() >= s.Manager.videosLimit {
		log.Println(v.ID() + " is old: skipping")
		return nil
	}
	err = s.Manager.checkUsedSpace()
	if err != nil {
		return err
	}
	sp := sources.SyncParams{
		ClaimAddress:   s.claimAddress,
		Amount:         publishAmount,
		ChannelID:      s.lbryChannelID,
		MaxVideoSize:   s.Manager.maxVideoSize,
		Namer:          s.namer,
		MaxVideoLength: s.Manager.maxVideoLength,
		Fee:            s.Fee,
	}

	summary, err := v.Sync(s.daemon, sp, &sv, videoRequiresUpgrade, s.walletMux)
	if err != nil {
		return err
	}

	s.AppendSyncedVideo(v.ID(), true, "", summary.ClaimName, summary.ClaimID, newMetadataVersion, *v.Size())
	err = s.Manager.apiConfig.MarkVideoStatus(sdk.VideoStatus{
		ChannelID:       s.YoutubeChannelID,
		VideoID:         v.ID(),
		Status:          VideoStatusPublished,
		ClaimID:         summary.ClaimID,
		ClaimName:       summary.ClaimName,
		Size:            v.Size(),
		MetaDataVersion: LatestMetadataVersion,
		IsTransferred:   util.PtrToBool(s.shouldTransfer()),
	})
	if err != nil {
		logUtils.SendErrorToSlack("Failed to mark video on the database: %s", errors.FullTrace(err))
	}

	return nil
}

func (s *Sync) importPublicKey() error {
	if s.publicKey != "" {
		accountsResponse, err := s.daemon.AccountList()
		if err != nil {
			return errors.Err(err)
		}
		accounts := accountsResponse.LBCMainnet
		if logUtils.IsRegTest() {
			accounts = accountsResponse.LBCRegtest
		}
		for _, a := range accounts {
			if a.PublicKey == s.publicKey {
				return nil
			}
		}
		log.Infof("Could not find public key %s in the wallet. Importing it...", s.publicKey)
		_, err = s.daemon.AccountAdd(s.LbryChannelName, nil, nil, &s.publicKey, util.PtrToBool(true), nil)
		return errors.Err(err)
	}
	return nil
}

//TODO: fully implement this once I find a way to reliably get the abandoned supports amount
func (s *Sync) getUnsentSupports() (float64, error) {
	defaultAccount, err := s.getDefaultAccount()
	if err != nil {
		return 0, errors.Err(err)
	}
	if s.transferState == 2 {
		balance, err := s.daemon.AccountBalance(&defaultAccount)
		if err != nil {
			return 0, err
		} else if balance == nil {
			return 0, errors.Err("no response")
		}

		balanceAmount, err := strconv.ParseFloat(balance.Available.String(), 64)
		if err != nil {
			return 0, errors.Err(err)
		}
		transactionList, err := s.daemon.TransactionList(&defaultAccount)
		if err != nil {
			return 0, errors.Err(err)
		}
		sentSupports := 0.0
		for _, t := range *transactionList {
			if len(t.SupportInfo) == 0 {
				continue
			}
			for _, support := range t.SupportInfo {
				supportAmount, err := strconv.ParseFloat(support.BalanceDelta, 64)
				if err != nil {
					return 0, err
				}
				if supportAmount < 0 { // && support.IsTip TODO: re-enable this when transaction list shows correct information
					sentSupports += -supportAmount
				}
			}
		}
		if balanceAmount > 10 && sentSupports < 1 {
			logUtils.SendErrorToSlack("this channel has quite some LBCs in it (%.2f) and %.2f LBC in sent tips, it's likely that the tips weren't actually sent or the wallet has unnecessary extra credits in it", balanceAmount, sentSupports)
			return balanceAmount - 10, nil
		}
	}
	return 0, nil
}

// waitForDaemonProcess observes the running processes and returns when the process is no longer running or when the timeout is up
func waitForDaemonProcess(timeout time.Duration) error {
	then := time.Now()
	stopTime := then.Add(time.Duration(timeout * time.Second))
	for !time.Now().After(stopTime) {
		wait := 10 * time.Second
		log.Println("the daemon is still running, waiting for it to exit")
		time.Sleep(wait)
		running, err := logUtils.IsLbrynetRunning()
		if err != nil {
			return errors.Err(err)
		}
		if !running {
			return nil
		}
	}
	return errors.Err("timeout reached")
}