Preserve media metadata across STRM path renames

internal/service/scanner_local_write_batch.go

@@ -7,6 +7,7 @@ import (
 	"go.uber.org/zap"
 
 	"github.com/truewhile/MeBox/internal/model"
+	"github.com/truewhile/MeBox/internal/repository"
 )
 
 type localMediaWriteBatch struct {
@@ -18,9 +19,10 @@ type localMediaWriteBatch struct {
 }
 
 type localMediaWriteItem struct {
-	path  string
-	media *model.Media
-	after func()
+	path    string
+	media   *model.Media
+	aliases []string
+	after   func()
 }
 
 func newLocalMediaWriteBatch(scanner *ScannerService, ctx context.Context, res *ScanResult, limit int) *localMediaWriteBatch {
@@ -41,7 +43,12 @@ func (b *localMediaWriteBatch) AddWithAfter(path string, media *model.Media, aft
 	if media.ScrapeStatus == "" {
 		media.ScrapeStatus = "pending"
 	}
-	b.items = append(b.items, localMediaWriteItem{path: path, media: media, after: after})
+	b.items = append(b.items, localMediaWriteItem{
+		path:    path,
+		media:   media,
+		aliases: missingSTRMPathAliases(path),
+		after:   after,
+	})
 	if len(b.items) >= b.limit {
 		b.Flush()
 	}
@@ -53,39 +60,35 @@ func (b *localMediaWriteBatch) Flush() {
 	}
 	items := b.items
 	b.items = nil
-	media := make([]model.Media, 0, len(items))
-	for _, item := range items {
-		if item.media != nil {
-			media = append(media, *item.media)
-		}
-	}
-	if len(media) == 0 {
-		return
-	}
-	existingPaths := b.existingPaths(items)
-	upsertItems := make([]*model.Media, 0, len(items))
-	upsertAfter := make([]func(), 0, len(items))
+
+	existingPaths, lookupOK := b.existingPathOrAliasSet(items)
+	upsertItems := make([]localMediaWriteItem, 0, len(items))
 	createItems := make([]localMediaWriteItem, 0, len(items))
-	createMedia := make([]model.Media, 0, len(items))
 	for _, item := range items {
 		if item.media == nil {
 			continue
 		}
-		if existingPaths[filepath.Clean(item.media.Path)] {
-			// 已存在行：攒起来在一个事务里逐条 upsert（一批一次提交）。
-			after := item.after
-			upsertItems = append(upsertItems, item.media)
-			upsertAfter = append(upsertAfter, after)
+		// If the alias lookup failed, route through UpsertWithAliases instead of
+		// direct-create. That is slower but cannot create a duplicate row.
+		if !lookupOK || mediaPathOrAliasExists(item.media.Path, item.aliases, existingPaths) {
+			upsertItems = append(upsertItems, item)
 			continue
 		}
 		createItems = append(createItems, item)
-		createMedia = append(createMedia, *item.media)
 	}
-	b.flushUpserts(items, upsertItems, upsertAfter)
-	if len(createMedia) == 0 {
+
+	b.flushUpserts(upsertItems)
+	if len(createItems) == 0 {
 		b.publish()
 		return
 	}
+
+	createMedia := make([]model.Media, 0, len(createItems))
+	for _, item := range createItems {
+		if item.media != nil {
+			createMedia = append(createMedia, *item.media)
+		}
+	}
 	if err := b.scanner.repo.DB.WithContext(b.ctx).CreateInBatches(&createMedia, b.limit).Error; err == nil {
 		b.res.Added += len(createMedia)
 		for _, item := range createItems {
@@ -96,12 +99,13 @@ func (b *localMediaWriteBatch) Flush() {
 		b.publish()
 		return
 	}
+
 	for _, item := range createItems {
 		if item.media == nil {
 			continue
 		}
 		wasExisting := b.mediaPathExists(item.media.Path)
-		if err := b.scanner.repo.Media.Upsert(b.ctx, item.media); err != nil {
+		if err := b.scanner.repo.Media.UpsertWithAliases(b.ctx, item.media, item.aliases); err != nil {
 			addScanError(b.res, item.path, err)
 			b.scanner.log.Warn("upsert media failed", zap.String("path", item.path), zap.Error(err))
 			continue
@@ -118,47 +122,90 @@ func (b *localMediaWriteBatch) Flush() {
 	b.publish()
 }
 
-func (b *localMediaWriteBatch) existingPaths(items []localMediaWriteItem) map[string]bool {
+// existingPathOrAliasSet loads exact and alias paths in bounded query chunks. Aliases
+// have already been filtered against the filesystem by AddWithAfter, so an
+// existing keep_ext sibling is never treated as a rename.
+func (b *localMediaWriteBatch) existingPathOrAliasSet(items []localMediaWriteItem) (map[string]bool, bool) {
 	out := map[string]bool{}
 	if b == nil || b.scanner == nil || b.scanner.repo == nil || b.scanner.repo.DB == nil || len(items) == 0 {
-		return out
+		return out, false
+	}
+	seen := make(map[string]struct{}, len(items)*2)
+	paths := make([]string, 0, len(items)*2)
+	add := func(path string) {
+		path = filepath.Clean(path)
+		if path == "" || path == "." {
+			return
+		}
+		if _, ok := seen[path]; ok {
+			return
+		}
+		seen[path] = struct{}{}
+		paths = append(paths, path)
 	}
-	paths := make([]string, 0, len(items))
 	for _, item := range items {
 		if item.media == nil || item.media.Path == "" {
 			continue
 		}
-		paths = append(paths, item.media.Path)
+		add(item.media.Path)
+		for _, alias := range item.aliases {
+			add(alias)
+		}
 	}
 	if len(paths) == 0 {
-		return out
+		return out, true
 	}
-	var rows []string
-	if err := b.scanner.repo.DB.WithContext(b.ctx).
-		Unscoped().
-		Model(&model.Media{}).
-		Where("path IN ?", paths).
-		Pluck("path", &rows).Error; err != nil {
-		b.scanner.log.Debug("load existing media paths for scan batch failed", zap.Error(err))
-		return out
+	// Keep SQL variables below the legacy SQLite limit (999). A batch can
+	// contain 100 STRM rows and every row has many sibling aliases.
+	const pathLookupChunk = 400
+	for start := 0; start < len(paths); start += pathLookupChunk {
+		end := start + pathLookupChunk
+		if end > len(paths) {
+			end = len(paths)
+		}
+		var rows []string
+		if err := b.scanner.repo.DB.WithContext(b.ctx).
+			Unscoped().
+			Model(&model.Media{}).
+			Where("path IN ?", paths[start:end]).
+			Pluck("path", &rows).Error; err != nil {
+			b.scanner.log.Debug("load existing media paths for scan batch failed", zap.Error(err))
+			return nil, false
+		}
+		for _, path := range rows {
+			out[filepath.Clean(path)] = true
+		}
 	}
-	for _, path := range rows {
-		out[filepath.Clean(path)] = true
-	}
-	return out
+	return out, true
 }
 
-// flushUpserts 把已存在行的 upsert 攒成一个事务（一次提交/一组 fsync）。
-// 整批失败（如单条数据触发约束）时退回逐条 Upsert，只丢真正坏的那几条。
-func (b *localMediaWriteBatch) flushUpserts(allItems []localMediaWriteItem, upsertItems []*model.Media, upsertAfter []func()) {
+func mediaPathOrAliasExists(path string, aliases []string, existing map[string]bool) bool {
+	if existing[filepath.Clean(path)] {
+		return true
+	}
+	for _, alias := range aliases {
+		if existing[filepath.Clean(alias)] {
+			return true
+		}
+	}
+	return false
+}
+
+// flushUpserts 把已存在或可迁移路径的行攒成一个事务（一次提交/一组 fsync）。
+// 整批失败（如单条数据触发约束）时退回逐条 upsert，只丢真正坏的那几条。
+func (b *localMediaWriteBatch) flushUpserts(upsertItems []localMediaWriteItem) {
 	if len(upsertItems) == 0 {
 		return
 	}
-	if err := b.scanner.repo.Media.UpsertBatch(b.ctx, upsertItems); err == nil {
+	batchItems := make([]repository.MediaUpsertItem, 0, len(upsertItems))
+	for _, item := range upsertItems {
+		batchItems = append(batchItems, repository.MediaUpsertItem{Media: item.media, AliasPaths: item.aliases})
+	}
+	if err := b.scanner.repo.Media.UpsertBatchWithAliases(b.ctx, batchItems); err == nil {
 		b.res.Updated += len(upsertItems)
-		for _, after := range upsertAfter {
-			if after != nil {
-				after()
+		for _, item := range upsertItems {
+			if item.after != nil {
+				item.after()
 			}
 		}
 		return
@@ -166,13 +213,7 @@ func (b *localMediaWriteBatch) flushUpserts(allItems []localMediaWriteItem, upse
 		b.scanner.log.Warn("batch upsert failed; falling back to per-item upsert",
 			zap.Int("items", len(upsertItems)))
 	}
-	// 兜底：按原始顺序找回每个条目的 path/after（两个切片同序但可能含 nil）。
-	idx := 0
-	for _, item := range allItems {
-		if item.media == nil || idx >= len(upsertItems) || upsertItems[idx] != item.media {
-			continue
-		}
-		idx++
+	for _, item := range upsertItems {
 		b.upsertExistingItem(item)
 	}
 }
@@ -181,7 +222,7 @@ func (b *localMediaWriteBatch) upsertExistingItem(item localMediaWriteItem) {
 	if item.media == nil {
 		return
 	}
-	if err := b.scanner.repo.Media.Upsert(b.ctx, item.media); err != nil {
+	if err := b.scanner.repo.Media.UpsertWithAliases(b.ctx, item.media, item.aliases); err != nil {
 		addScanError(b.res, item.path, err)
 		b.scanner.log.Warn("upsert media failed", zap.String("path", item.path), zap.Error(err))
 		return