v0.2.1: add status messages, fix parallel export progress

- mustAuth: print 'requesting photo library access...' / 'access granted'
- cmdBackupAll: print 'loading photo library tree...' / 'found N albums'
- cmdExport: print 'loading assets...' / 'exporting N assets (mode)...'
- backupTree: print 'album: Name (N assets)' per album
- exportAssetsParallel: slot-based progress shows each asset as it completes
  instead of waiting for all to finish
- Fix data race: use jobs channel instead of shared range iteration

cmd/photoscli/main.go

@@ -67,10 +67,12 @@ Flags:
 }
 
 func mustAuth(stderr io.Writer, bridge photos.Bridge) int {
+	fmt.Fprintln(stderr, "requesting photo library access...")
 	if err := bridge.RequestAccess(); err != nil {
 		fmt.Fprintf(stderr, "error: %v\n", err)
 		return 1
 	}
+	fmt.Fprintln(stderr, "access granted")
 	return 0
 }
 
@@ -78,6 +80,7 @@ func cmdAlbums(stdout, stderr io.Writer, bridge photos.Bridge) int {
 	if rc := mustAuth(stderr, bridge); rc != 0 {
 		return rc
 	}
+	fmt.Fprintln(stderr, "loading albums...")
 	albums, err := bridge.ListAlbums()
 	if err != nil {
 		fmt.Fprintf(stderr, "error: %v\n", err)
@@ -179,12 +182,14 @@ func cmdExport(args []string, stdout, stderr io.Writer, bridge photos.Bridge) in
 		}
 	}
 
+	fmt.Fprintf(stderr, "loading assets for album %s...\n", albumID)
 	assets, total, err := bridge.ListAssets(resolved)
 	if err != nil {
 		fmt.Fprintf(stderr, "error: %v\n", err)
 		return 1
 	}
 
+	fmt.Fprintf(stderr, "exporting %d assets (%s) to %s...\n", total, exportMode(originals), outDir)
 	exported, failed := exportAssets(assets, outDir, size, originals, total, stderr, bridge, "")
 
 	if exported == 0 && failed > 0 {
@@ -226,12 +231,14 @@ func cmdBackupAll(args []string, stdout, stderr io.Writer, bridge photos.Bridge)
 		}
 	}
 
+	fmt.Fprintln(stderr, "loading photo library tree...")
 	nodes, err := bridge.ListTree()
 	if err != nil {
 		fmt.Fprintf(stderr, "error: %v\n", err)
 		return 1
 	}
 	albumCount := countAlbums(nodes)
+	fmt.Fprintf(stderr, "found %d albums, exporting to %s...\n", albumCount, outDir)
 
 	totalAssets, _, failed, err := backupTree(nodes, outDir, size, originals, stderr, bridge)
 	if err != nil {
@@ -273,6 +280,7 @@ func backupTree(nodes []photos.CollectionNode, outDir string, targetSize int, or
 				fmt.Fprintf(stderr, "\n  skipped album %s: %v\n", node.Name, err)
 				continue
 			}
+			fmt.Fprintf(stderr, "\nalbum: %s (%d assets)\n", node.Name, assetTotal)
 			total += assetTotal
 			n, f := exportAssets(assets, path, targetSize, originals, total, stderr, bridge, path+"/")
 			exported += n
@@ -282,17 +290,6 @@ func backupTree(nodes []photos.CollectionNode, outDir string, targetSize int, or
 	return exported, total, failed, nil
 }
 
-type exportJob struct {
-	asset photos.Asset
-	index int
-}
-
-type exportResult struct {
-	index  int
-	result photos.ExportResult
-	err    error
-}
-
 func exportAssets(assets []photos.Asset, outDir string, targetSize int, originals bool, total int, stderr io.Writer, bridge photos.Bridge, dirPrefix string) (int, int) {
 	if len(assets) == 0 {
 		return 0, 0
@@ -322,50 +319,51 @@ func exportAssetsSerial(assets []photos.Asset, outDir string, targetSize int, or
 }
 
 func exportAssetsParallel(assets []photos.Asset, outDir string, targetSize int, originals bool, total int, stderr io.Writer, bridge photos.Bridge, workers int, dirPrefix string) (int, int) {
-	jobs := make(chan exportJob, len(assets))
-	results := make(chan exportResult, len(assets))
+	type slot struct {
+		result photos.ExportResult
+		err    error
+		done   chan struct{}
+	}
 
+	slots := make([]slot, len(assets))
+	for i := range slots {
+		slots[i].done = make(chan struct{})
+	}
+
+	jobs := make(chan int, len(assets))
 	var wg sync.WaitGroup
 	for w := 0; w < workers; w++ {
 		wg.Add(1)
 		go func() {
 			defer wg.Done()
-			for job := range jobs {
-				result, exportErr := exportOne(bridge, job.asset, outDir, targetSize, originals, job.index)
-				results <- exportResult{index: job.index, result: result, err: exportErr}
+			for i := range jobs {
+				result, exportErr := exportOne(bridge, assets[i], outDir, targetSize, originals, i)
+				slots[i].result = result
+				slots[i].err = exportErr
+				close(slots[i].done)
 			}
 		}()
 	}
 
-	go func() {
-		for i, a := range assets {
-			jobs <- exportJob{asset: a, index: i}
-		}
-		close(jobs)
-	}()
-
-	go func() {
-		wg.Wait()
-		close(results)
-	}()
-
-	ordered := make([]exportResult, len(assets))
-	for r := range results {
-		ordered[r.index] = r
+	for i := range assets {
+		jobs <- i
 	}
+	close(jobs)
 
 	exported := 0
 	failed := 0
 	for i, a := range assets {
-		r := ordered[i]
-		progressBar(stderr, exported+failed+1, total, dirPrefix+r.result.Filename, r.result.Size, r.result.Cloud)
-		if r.err != nil {
-			fmt.Fprintf(stderr, "\n  failed: %s: %v\n", a.Filename, r.err)
+		<-slots[i].done
+		s := slots[i]
+		progressBar(stderr, exported+failed+1, total, dirPrefix+s.result.Filename, s.result.Size, s.result.Cloud)
+		if s.err != nil {
+			fmt.Fprintf(stderr, "\n  failed: %s: %v\n", a.Filename, s.err)
 			failed++
 			continue
 		}
 		exported++
 	}
+	wg.Wait()
 	return exported, failed
 }
 
@@ -452,3 +450,10 @@ func formatSize(bytes int64) string {
 	}
 	return fmt.Sprintf("%.1f KB", float64(bytes)/float64(kb))
 }
+
+func exportMode(originals bool) string {
+	if originals {
+		return "originals"
+	}
+	return "previews"
+}