Split FSScanner.Scan into FileDiscoverer, ProbeWorker, ScanWriter (ba)

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

1 files changed, 75 insertions, 0 deletions

diff --git a/player-server/internal/scanner/file_discoverer.go b/player-server/internal/scanner/file_discoverer.go
new file mode 100644
index 0000000..bb77d61
--- /dev/null
+++ b/player-server/internal/scanner/file_discoverer.go
@@ -0,0 +1,75 @@
+// Package scanner implements media library scanning logic.
+package scanner
+
+import (
+	"fmt"
+	"io/fs"
+	"path/filepath"
+	"strings"
+
+	"codeberg.org/snonux/player/internal/mediatype"
+)
+
+// fileDiscoverer walks a set directory and collects media file paths and
+// cover image locations. It is responsible solely for filesystem traversal —
+// it does not probe, store, or generate thumbnails.
+type fileDiscoverer struct {
+	fs FS
+}
+
+// newFileDiscoverer creates a fileDiscoverer backed by the given filesystem abstraction.
+func newFileDiscoverer(fs FS) *fileDiscoverer {
+	return &fileDiscoverer{fs: fs}
+}
+
+// Discover walks setPath and returns the absolute paths of all supported media
+// files, skipping hidden directories (names starting with ".").
+func (d *fileDiscoverer) Discover(setPath string) ([]string, error) {
+	var files []string
+	walkErr := d.fs.WalkDir(setPath, func(path string, entry fs.DirEntry, err error) error {
+		if err != nil {
+			return fmt.Errorf("walk %q: %w", path, err)
+		}
+		// Skip hidden directories (e.g. .git, .thumbnails) to avoid
+		// accidentally ingesting dot-prefixed paths.
+		if entry.IsDir() {
+			if strings.HasPrefix(entry.Name(), ".") && path != setPath {
+				return filepath.SkipDir
+			}
+			return nil
+		}
+		if !mediatype.IsSupportedExt(path) {
+			return nil
+		}
+		files = append(files, path)
+		return nil
+	})
+	if walkErr != nil {
+		return nil, walkErr
+	}
+	return files, nil
+}
+
+// gatherCoverImages walks the set directory and records the first cover image
+// per directory. The returned map is keyed by absolute directory path; values
+// are the image path relative to setPath so callers can join them as needed.
+func (d *fileDiscoverer) gatherCoverImages(setPath string) map[string]string {
+	coverImages := make(map[string]string)
+	_ = d.fs.WalkDir(setPath, func(path string, entry fs.DirEntry, err error) error {
+		if err != nil || entry.IsDir() || !mediatype.IsCoverImageExt(path) {
+			// Skip hidden subdirectories, but tolerate walk errors silently
+			// since missing cover images are non-fatal.
+			if entry != nil && entry.IsDir() && strings.HasPrefix(entry.Name(), ".") && path != setPath {
+				return filepath.SkipDir
+			}
+			return nil
+		}
+		relPath, _ := filepath.Rel(setPath, path)
+		dir := filepath.Dir(path)
+		if _, ok := coverImages[dir]; !ok {
+			coverImages[dir] = relPath
+		}
+		return nil
+	})
+	return coverImages
+}