feat: report progress while reading a chat and listing a remote

Both phases ran for minutes printing nothing between their opening line and
their result, so a working run looked exactly like a hung one — which is how it
was reported.

The message counter lives in Walk rather than in the caller's loop because most
of a chat is not media: text-only and service messages are filtered out inside
the walk, so a caller counting yielded items still sees nothing while crossing a
long stretch of conversation.

Cadence follows the existing reporter: a terminal redraws one line, a redirected
run gets a periodic one, since ANSI redraws are what turned the shell pipeline's
captured logs into megabytes of control characters.

cmd/tgexport/list.go

@@ -11,6 +11,7 @@ import (
 	"github.com/iyear/tdl/core/dcpool"
 	tdlstorage "github.com/iyear/tdl/core/storage"
 
+	"github.com/tiennm99dev/telegram-exporter/internal/report"
 	"github.com/tiennm99dev/telegram-exporter/internal/tdlkv"
 	"github.com/tiennm99dev/telegram-exporter/internal/tgsource"
 )
@@ -66,9 +67,10 @@ func listCmd(ctx context.Context, args []string) error {
 		// swallowed by a deferred call nobody checks.
 		out := bufio.NewWriter(os.Stdout)
 
+		scan := report.NewTicker(os.Stderr, "messages read")
 		count := 0
 		var total int64
-		for it, err := range tgsource.Walk(ctx, api, peer) {
+		for it, err := range tgsource.Walk(ctx, api, peer, scan.Update) {
 			if err != nil {
 				return err
 			}

cmd/tgexport/sync.go

@@ -122,15 +122,21 @@ func syncCmd(ctx context.Context, args []string) error {
 		}
 
 		fmt.Fprintf(os.Stderr, "reading %s\n", *chat)
+		scan := report.NewTicker(os.Stderr, "messages read")
 		var items []tgsource.Item
-		for it, err := range tgsource.Walk(ctx, api, peer) {
+		var scanned int
+		for it, err := range tgsource.Walk(ctx, api, peer, func(n int) {
+			scanned = n
+			scan.Update(n)
+		}) {
 			if err != nil {
 				return err
 			}
 			items = append(items, it)
 		}
+		scan.Done(scanned)
 
-		idx, err := remote.BuildIndex(ctx, dst, peer.ID())
+		idx, err := indexRemote(ctx, dst, peer.ID())
 		if err != nil {
 			return err
 		}
@@ -191,7 +197,7 @@ func syncCmd(ctx context.Context, args []string) error {
 
 		// The remote is re-indexed rather than assumed: the run's own view of
 		// what it uploaded is exactly the thing under test.
-		idx, err = remote.BuildIndex(ctx, dst, peer.ID())
+		idx, err = indexRemote(ctx, dst, peer.ID())
 		if err != nil {
 			return err
 		}
@@ -280,6 +286,22 @@ func validateBudget(budget int64, todo []tgsource.Item) error {
 	return nil
 }
 
+// indexRemote lists the destination, reporting progress as it goes.
+func indexRemote(ctx context.Context, dst fs.Fs, dialogID int64) (*remote.Index, error) {
+	fmt.Fprintf(os.Stderr, "indexing %s\n", dst.String())
+	tick := report.NewTicker(os.Stderr, "objects listed")
+	var seen int
+	idx, err := remote.BuildIndex(ctx, dst, dialogID, func(n int) {
+		seen = n
+		tick.Update(n)
+	})
+	if err != nil {
+		return nil, err
+	}
+	tick.Done(seen)
+	return idx, nil
+}
+
 // warnCollisions reports basenames the index found at more than one path.
 //
 // verify printed this and sync did not, which was backwards: an ambiguous

cmd/tgexport/verify.go

@@ -15,6 +15,7 @@ import (
 	"github.com/rclone/rclone/fs/operations"
 
 	"github.com/tiennm99dev/telegram-exporter/internal/remote"
+	"github.com/tiennm99dev/telegram-exporter/internal/report"
 	"github.com/tiennm99dev/telegram-exporter/internal/tdlkv"
 	"github.com/tiennm99dev/telegram-exporter/internal/tgsource"
 	"github.com/tiennm99dev/telegram-exporter/internal/verify"
@@ -66,7 +67,7 @@ func verifyCmd(ctx context.Context, args []string) error {
 	}
 
 	var (
-		report verify.Report
+		result verify.Report
 		idx    *remote.Index
 	)
 	if err := sess.Run(ctx, func(ctx context.Context, pool dcpool.Pool) error {
@@ -80,19 +81,30 @@ func verifyCmd(ctx context.Context, args []string) error {
 		// The chat is walked first and the remote listed second, so the snapshot
 		// is never older than the wanted set. The reverse order could report a
 		// file absent that was uploaded while the walk was still running.
+		fmt.Fprintf(os.Stderr, "reading %s\n", *chat)
+		scan := report.NewTicker(os.Stderr, "messages read")
+		var scanned int
 		var items []tgsource.Item
-		for it, err := range tgsource.Walk(ctx, api, peer) {
+		for it, err := range tgsource.Walk(ctx, api, peer, func(n int) { scanned = n; scan.Update(n) }) {
 			if err != nil {
 				return err
 			}
 			items = append(items, it)
 		}
 
-		idx, err = remote.BuildIndex(ctx, dst, peer.ID())
+		scan.Done(scanned)
+
+		fmt.Fprintf(os.Stderr, "indexing %s\n", dst.String())
+		idxTick := report.NewTicker(os.Stderr, "objects listed")
+		var listed int
+		idx, err = remote.BuildIndex(ctx, dst, peer.ID(), func(n int) {
+			listed = n
+			idxTick.Update(n)
+		})
 		if err != nil {
 			return err
 		}
-		fmt.Fprintf(os.Stderr, "indexed %d objects on %s\n", idx.Len(), dst.String())
+		idxTick.Done(listed)
 		if dup := idx.Collisions(); len(dup) > 0 {
 			// An ambiguous snapshot makes every verdict about these names
 			// unreliable, so it is reported rather than silently resolved.
@@ -104,26 +116,26 @@ func verifyCmd(ctx context.Context, args []string) error {
 		}
 		fmt.Fprintln(os.Stderr)
 
-		report = verify.Check(items, idx)
+		result = verify.Check(items, idx)
 		return nil
 	}); err != nil {
 		return err
 	}
 
 	out := bufio.NewWriter(os.Stdout)
-	report.Write(out)
+	result.Write(out)
 	if err := out.Flush(); err != nil {
 		return err
 	}
 
 	if *delStale {
-		if err := deleteMisnamed(ctx, dst, idx, report, *assumeYes); err != nil {
+		if err := deleteMisnamed(ctx, dst, idx, result, *assumeYes); err != nil {
 			return err
 		}
 	}
 
-	if !report.Complete() {
-		return fmt.Errorf("%w: %d file(s) still to fetch", errIncomplete, len(report.Todo()))
+	if !result.Complete() {
+		return fmt.Errorf("%w: %d file(s) still to fetch", errIncomplete, len(result.Todo()))
 	}
 	return nil
 }
@@ -138,9 +150,9 @@ func verifyCmd(ctx context.Context, args []string) error {
 // used elsewhere. Those differ the moment a remote has directory structure, and
 // deleting by basename would either miss the object or — worse, if the root
 // happens to hold a same-named file — delete the wrong one.
-func deleteMisnamed(ctx context.Context, dst rclonefs.Fs, idx *remote.Index, report verify.Report, assumeYes bool) error {
+func deleteMisnamed(ctx context.Context, dst rclonefs.Fs, idx *remote.Index, result verify.Report, assumeYes bool) error {
 	var targets []string
-	for _, m := range report.Misnamed {
+	for _, m := range result.Misnamed {
 		targets = append(targets, m.Found...)
 	}
 	if len(targets) == 0 {