From a9a384972649182c188396c5f996ae617d35188a Mon Sep 17 00:00:00 2001
From: Martin Kagamino Lehoux <martin@lehoux.net>
Date: Mon, 24 Aug 2026 12:07:30 +0200
Subject: Add progress bars to the long-running CLI processes (backtest,
 backfill, extract-osm)

---
 mountain_pass/extract.go | 32 ++++++++++++++++++++++++++++++--
 1 file changed, 30 insertions(+), 2 deletions(-)

(limited to 'mountain_pass/extract.go')

diff --git a/mountain_pass/extract.go b/mountain_pass/extract.go
index 705dbd3..9643603 100644
--- a/mountain_pass/extract.go
+++ b/mountain_pass/extract.go
@@ -24,14 +24,28 @@ const insertStatement = `
 		longitude = excluded.longitude
 `
 
-func ExtractMountainPasses(ctx context.Context, pbfPath string, db *sql.DB) (int, error) {
+// ExtractMountainPasses scans pbfPath for mountain pass nodes and upserts them
+// into the database. An optional reporter is invoked as scanning progresses
+// with bytes scanned and the total file size, so callers (e.g. the CLI) can
+// render progress.
+func ExtractMountainPasses(ctx context.Context, pbfPath string, db *sql.DB, reporters ...func(current, total int64)) (int, error) {
 	file, err := os.Open(pbfPath)
 	if err != nil {
 		return 0, fmt.Errorf("failed to open pbf file: %w", err)
 	}
 	defer file.Close()
 
-	scanner := osmpbf.New(ctx, file, 4)
+	info, err := file.Stat()
+	if err != nil {
+		return 0, fmt.Errorf("failed to stat pbf file: %w", err)
+	}
+	total := info.Size()
+	report := func(int64, int64) {}
+	if len(reporters) > 0 {
+		report = reporters[0]
+	}
+	reader := &countingReader{r: file}
+	scanner := osmpbf.New(ctx, reader, 4)
 	scanner.SkipWays = true
 	scanner.SkipRelations = true
 	scanner.FilterNode = isMountainPass
@@ -50,6 +64,7 @@ func ExtractMountainPasses(ctx context.Context, pbfPath string, db *sql.DB) (int
 
 	count := 0
 	for scanner.Scan() {
+		report(reader.n, total)
 		node, ok := scanner.Object().(*osm.Node)
 		if !ok {
 			continue
@@ -74,6 +89,19 @@ func ExtractMountainPasses(ctx context.Context, pbfPath string, db *sql.DB) (int
 	return count, nil
 }
 
+// countingReader tracks the number of bytes read from an underlying reader,
+// used to report scan progress against the PBF file size.
+type countingReader struct {
+	r io.Reader
+	n int64
+}
+
+func (c *countingReader) Read(p []byte) (int, error) {
+	n, err := c.r.Read(p)
+	c.n += int64(n)
+	return n, err
+}
+
 func isMountainPass(node *osm.Node) bool {
 	if node.Tags.Find("mountain_pass") == "yes" {
 		return true
-- 
cgit v1.3