feat(global, download): add —delay flag

app/dl/dl.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"time"
 
 	"github.com/AlecAivazis/survey/v2"
 	"github.com/fatih/color"
@@ -38,6 +39,7 @@ type Options struct {
 	Exclude    []string
 	Desc       bool
 	Takeout    bool
+	Delay      time.Duration
 
 	// resume opts
 	Continue, Restart bool
@@ -107,6 +109,7 @@ func Run(ctx context.Context, c *telegram.Client, kvd kv.KV, opts Options) (rerr
 		Threads:  viper.GetInt(consts.FlagThreads),
 		Iter:     it,
 		Progress: newProgress(dlProgress, it, opts),
+		Delay:    viper.GetDuration(consts.FlagDelay),
 	}
 	limit := viper.GetInt(consts.FlagLimit)
 

app/dl/iter.go

@@ -94,6 +94,14 @@ func newIter(pool dcpool.Pool, manager *peers.Manager, dialog [][]*tmessage.Dial
 	}, nil
 }
 
+func (i *iter) HasNext() bool {
+	i.mu.Lock()
+	defer i.mu.Unlock()
+
+	j := i.j + 1
+	return i.i < len(i.dialogs) && j < len(i.dialogs[i.i].Messages)
+}
+
 func (i *iter) Next(ctx context.Context) bool {
 	select {
 	case <-ctx.Done():

cmd/root.go

@@ -99,6 +99,7 @@ func New() *cobra.Command {
 	cmd.PersistentFlags().Duration(consts.FlagReconnectTimeout, 5*time.Minute, "Telegram client reconnection backoff timeout, infinite if set to 0") // #158
 
 	cmd.PersistentFlags().String(consts.FlagTest, "", "use test Telegram client, only for developer")
+	cmd.PersistentFlags().Duration(consts.FlagDelay, 0, "delay between each download, forward and upload task")
 
 	// completion
 	_ = cmd.RegisterFlagCompletionFunc(consts.FlagNamespace, func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {

pkg/consts/flag.go

@@ -13,4 +13,5 @@ const (
 	FlagReconnectTimeout = "reconnect-timeout"
 	FlagDlTemplate       = "template"
 	FlagTest             = "test"
+	FlagDelay            = "delay"
 )

pkg/downloader/downloader.go

@@ -2,6 +2,8 @@ package downloader
 
 import (
 	"context"
+	"github.com/fatih/color"
+	"time"
 
 	"github.com/go-faster/errors"
 	"github.com/gotd/td/telegram/downloader"
@@ -23,6 +25,7 @@ type Options struct {
 	Threads  int
 	Iter     Iter
 	Progress Progress
+	Delay    time.Duration
 }
 
 func New(opts Options) *Downloader {
@@ -51,6 +54,11 @@ func (d *Downloader) Download(ctx context.Context, limit int) error {
 				// don't return error, just log it
 			}
 
+			if d.opts.Delay != 0 && d.opts.Iter.HasNext() {
+				color.Yellow("Delay %s", d.opts.Delay.String())
+				<-time.After(d.opts.Delay)
+			}
+
 			return nil
 		})
 	}

pkg/downloader/iter.go

@@ -9,6 +9,7 @@ import (
 
 type Iter interface {
 	Next(ctx context.Context) bool
+	HasNext() bool
 	Value() Elem
 	Err() error
 }