feat: batch STRM tree generation

internal/handler/strm.go

@@ -119,6 +119,7 @@ type generateSTRMTreeReq struct {
 	Overwrite    bool     `json:"overwrite"`
 	Cleanup      bool     `json:"cleanup"`
 	DryRun       bool     `json:"dry_run"`
+	BatchLimit   int      `json:"batch_limit"`
 }
 
 func generateSTRMHandler(svc *service.Container) gin.HandlerFunc {
@@ -191,6 +192,7 @@ func generateSTRMFromTreeHandler(svc *service.Container) gin.HandlerFunc {
 			Overwrite:    req.Overwrite,
 			Cleanup:      req.Cleanup,
 			DryRun:       req.DryRun,
+			BatchLimit:   req.BatchLimit,
 		})
 		if err != nil {
 			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})

internal/service/strm_tree_import.go

@@ -20,6 +20,7 @@ type GenerateSTRMTreeOptions struct {
 	Overwrite    bool     `json:"overwrite"`
 	Cleanup      bool     `json:"cleanup"`
 	DryRun       bool     `json:"dry_run"`
+	BatchLimit   int      `json:"batch_limit,omitempty"`
 }
 
 type strmTreeSource struct {
@@ -55,8 +56,11 @@ func (s *STRMService) GenerateFromTree(ctx context.Context, opts GenerateSTRMTre
 			expectedFiles[filepath.Clean(item.FilePath)] = struct{}{}
 		}
 		result.addItem(item)
+		if strmTreeBatchLimitReached(result, opts.BatchLimit) {
+			break
+		}
 	}
-	if opts.Cleanup && !opts.DryRun && len(expectedFiles) > 0 {
+	if opts.Cleanup && !opts.DryRun && opts.BatchLimit <= 0 && len(expectedFiles) > 0 {
 		cleanupDir := outputDir
 		if prefix, err := strmTreeOutputPrefixPath(opts.OutputPrefix); err == nil && prefix != "" {
 			cleanupDir = filepath.Join(outputDir, prefix)
@@ -70,6 +74,13 @@ func (s *STRMService) GenerateFromTree(ctx context.Context, opts GenerateSTRMTre
 	return result, nil
 }
 
+func strmTreeBatchLimitReached(result *GenerateSTRMResult, limit int) bool {
+	if result == nil || limit <= 0 {
+		return false
+	}
+	return result.Generated+result.Updated+result.Previewed >= limit
+}
+
 func generateTreeSTRMItem(outputDir string, source strmTreeSource, opts GenerateSTRMTreeOptions) GenerateSTRMItem {
 	relSource := strmTreeRelativeSource(source.Path, opts.SourceRoot)
 	relPath, err := strmTreeOutputRelativePath(relSource)

internal/service/strm_tree_import_test.go

@@ -137,3 +137,65 @@ func TestGenerateSTRMFromTreeDryRunDoesNotCreateOutputDir(t *testing.T) {
 		t.Fatalf("dry run should not create output dir, stat err=%v", err)
 	}
 }
+
+func TestGenerateSTRMFromTreeBatchLimitContinuesAfterExistingFiles(t *testing.T) {
+	outDir := filepath.Join(t.TempDir(), "strm")
+	svc := NewSTRMService(zap.NewNop(), nil, nil)
+	opts := GenerateSTRMTreeOptions{
+		Provider:   "openlist",
+		Paths:      []string{"/Movies/A.mkv", "/Movies/B.mkv", "/Movies/C.mkv"},
+		OutputDir:  outDir,
+		BatchLimit: 2,
+	}
+
+	first, err := svc.GenerateFromTree(t.Context(), opts)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if first.Generated != 2 || first.Skipped != 0 {
+		t.Fatalf("first batch = %#v, want two generated", first)
+	}
+	if _, err := os.Stat(filepath.Join(outDir, "Movies", "C.strm")); !os.IsNotExist(err) {
+		t.Fatalf("first batch should not write third item, stat err=%v", err)
+	}
+
+	second, err := svc.GenerateFromTree(t.Context(), opts)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if second.Generated != 1 || second.Skipped != 2 {
+		t.Fatalf("second batch = %#v, want two existing skips then next generated", second)
+	}
+	if got := readSTRM(t, filepath.Join(outDir, "Movies", "C.strm")); !strings.Contains(got, "C.mkv") {
+		t.Fatalf("second batch C.strm = %q, want generated third item", got)
+	}
+}
+
+func TestGenerateSTRMFromTreeBatchLimitSkipsCleanup(t *testing.T) {
+	outDir := filepath.Join(t.TempDir(), "strm")
+	stale := filepath.Join(outDir, "Movies", "stale.strm")
+	if err := os.MkdirAll(filepath.Dir(stale), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(stale, []byte("keep\n"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	svc := NewSTRMService(zap.NewNop(), nil, nil)
+
+	res, err := svc.GenerateFromTree(t.Context(), GenerateSTRMTreeOptions{
+		Provider:   "openlist",
+		Paths:      []string{"/Movies/A.mkv", "/Movies/B.mkv"},
+		OutputDir:  outDir,
+		BatchLimit: 1,
+		Cleanup:    true,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if res.Generated != 1 || res.Cleaned != 0 {
+		t.Fatalf("batch result = %#v, want one generated and no cleanup", res)
+	}
+	if got := readSTRM(t, stale); got != "keep" {
+		t.Fatalf("batch cleanup should not touch stale file: %q", got)
+	}
+}