feat(par2): generate single PAR2 set per folder with relative paths in FileDesc

.gitignore

@@ -29,3 +29,5 @@ postie-cli
 # ClaudPoint checkpoint system
 .checkpoints/
 example/
+# CocoIndex Code (ccc)
+/.cocoindex_code/

go.mod

@@ -11,7 +11,7 @@ require (
 	github.com/javi11/nntppool/v4 v4.11.1
 	github.com/javi11/nxg v0.1.0
 	github.com/javi11/nzbparser v0.5.4
-	github.com/javi11/par2go v0.0.7
+	github.com/javi11/par2go v0.0.8
 	github.com/klauspost/compress v1.18.2
 	github.com/mattn/go-sqlite3 v1.14.32
 	github.com/mnightingale/rapidyenc v0.0.0-20251128204712-7aafef1eaf1c

go.sum

@@ -345,16 +345,14 @@ github.com/jackc/puddle/v2 v2.2.2 h1:PR8nw+E/1w0GLuRFSmiioY6UooMp6KJv0/61nB7icHo
 github.com/jackc/puddle/v2 v2.2.2/go.mod h1:vriiEXHvEE654aYKXXjOvZM39qJ0q+azkZFrfEOc3H4=
 github.com/jackmordaunt/icns v1.0.0 h1:RYSxplerf/l/DUd09AHtITwckkv/mqjVv4DjYdPmAMQ=
 github.com/jackmordaunt/icns v1.0.0/go.mod h1:7TTQVEuGzVVfOPPlLNHJIkzA6CoV7aH1Dv9dW351oOo=
-github.com/javi11/nntppool/v4 v4.10.1 h1:NHoRniTnCRgpt/niljsWjA3gP5pYtNwxaqbLdr0Bcew=
-github.com/javi11/nntppool/v4 v4.10.1/go.mod h1:+UtisJLDFLXBSkW9R6uCRgdp3lS/+6pLAk7L+Wt6LMw=
 github.com/javi11/nntppool/v4 v4.11.1 h1:581fZSPv+RyIKY2hI0GB0eZrm1rCbAp+HRP5nIp7kd0=
 github.com/javi11/nntppool/v4 v4.11.1/go.mod h1:+UtisJLDFLXBSkW9R6uCRgdp3lS/+6pLAk7L+Wt6LMw=
 github.com/javi11/nxg v0.1.0 h1:CTThldYlaVIPIhpkrMw0HcTD0NLrW1uYMoDILjjEOtM=
 github.com/javi11/nxg v0.1.0/go.mod h1:+GvYpp+y1oq+qBOWxFMvfTjtin/0zCeomWfjiPkiu8A=
 github.com/javi11/nzbparser v0.5.4 h1:0aYyORZipp7iX8eNpT/efnzCeVO+9C0sE2HWCGc/JaI=
 github.com/javi11/nzbparser v0.5.4/go.mod h1:ikF7WI3BUGs5IHQJmKzmtTkX29NZW5nvUdo6ZWFZgL4=
-github.com/javi11/par2go v0.0.7 h1:30KMAvFHCBheMkg6b+D1Pi+xx5EvGeXZdfKeoLDv3vc=
-github.com/javi11/par2go v0.0.7/go.mod h1:GXuKNiRmZGv4rGia0FR23016IbcrsTMvLHihytsSnMU=
+github.com/javi11/par2go v0.0.8 h1:dnEaRIHIxJZ9dQg2AZ6h/mD9L11xFpdAfaA+vWg2pAI=
+github.com/javi11/par2go v0.0.8/go.mod h1:GXuKNiRmZGv4rGia0FR23016IbcrsTMvLHihytsSnMU=
 github.com/jaypipes/ghw v0.13.0 h1:log8MXuB8hzTNnSktqpXMHc0c/2k/WgjOMSUtnI1RV4=
 github.com/jaypipes/ghw v0.13.0/go.mod h1:In8SsaDqlb1oTyrbmTC14uy+fbBMvp+xdqX51MidlD8=
 github.com/jaypipes/pcidb v1.0.1 h1:WB2zh27T3nwg8AE8ei81sNRb9yWBii3JGNJtT7K9Oic=

internal/par2/binary.go

@@ -41,6 +41,160 @@ func (b *BinaryExecutor) Create(ctx context.Context, files []fileinfo.FileInfo)
 	return b.CreateInDirectory(ctx, files, "")
 }
 
+// CreateSet bundles all input files into a single par2 set named setName,
+// using parpar's --filepath-format=common so each FileDesc carries the
+// folderDir as --filepath-base so parpar records each file's path relative
+// to folderDir in the FileDesc packet, letting SABnzbd / NZBGet recreate
+// the folder tree inside the job directory on disk.
+func (b *BinaryExecutor) CreateSet(ctx context.Context, files []fileinfo.FileInfo, outputDir, setName, folderDir string) ([]string, error) {
+	if len(files) == 0 {
+		return nil, fmt.Errorf("par2: no input files for set %q", setName)
+	}
+	if setName == "" {
+		return nil, fmt.Errorf("par2: empty set name")
+	}
+
+	inputs := make([]fileinfo.FileInfo, 0, len(files))
+	for _, f := range files {
+		if filepath.Ext(f.Path) == ".par2" {
+			continue
+		}
+		inputs = append(inputs, f)
+	}
+	if len(inputs) == 0 {
+		return nil, fmt.Errorf("par2: no non-par2 input files for set %q", setName)
+	}
+
+	dirPath := outputDir
+	if dirPath == "" {
+		if b.cfg.TempDir != "" {
+			dirPath = b.cfg.TempDir
+		} else {
+			dirPath = filepath.Dir(inputs[0].Path)
+		}
+	}
+	if err := os.MkdirAll(dirPath, 0755); err != nil {
+		return nil, fmt.Errorf("par2: create output dir %s: %w", dirPath, err)
+	}
+
+	if existing, ok := checkExistingPar2SetInPath(ctx, setName, dirPath); ok {
+		return existing, nil
+	}
+
+	totalSize := uint64(0)
+	maxFileSize := uint64(0)
+	for _, f := range inputs {
+		totalSize += f.Size
+		if f.Size > maxFileSize {
+			maxFileSize = f.Size
+		}
+	}
+	blockSize := calculateParBlockSize(totalSize, b.articleSize)
+	if maxFileSize > 0 && blockSize > maxFileSize {
+		blockSize = alignDown(maxFileSize, 4)
+	}
+	if blockSize < 4 {
+		slog.WarnContext(ctx, "Block size too small for PAR2 set creation, skipping",
+			"setName", setName, "totalSize", totalSize)
+		return nil, nil
+	}
+	totalSlices := 0
+	for _, f := range inputs {
+		n := int(math.Ceil(float64(f.Size) / float64(blockSize)))
+		if n == 0 {
+			n = 1
+		}
+		totalSlices += n
+	}
+	redundancyPct := parseRedundancyPercentage(b.cfg.Redundancy, totalSize, blockSize)
+	numRecovery := max(int(math.Ceil(float64(totalSlices)*redundancyPct/100.0)), 1)
+
+	outputBase := filepath.Join(dirPath, setName)
+
+	// Use folderDir as --filepath-base so parpar records each file's path
+	// relative to the folder root (e.g. "extras/bonus.mkv").  This is the
+	// explicit folder root passed by the caller, which is always correct
+	// regardless of whether all input files happen to share a subdirectory.
+	args := []string{
+		"-s", fmt.Sprintf("%db", blockSize),
+		"-r", fmt.Sprintf("%d", numRecovery),
+		"-o", outputBase,
+		"--filepath-base", folderDir,
+		"--filepath-format", "outrel",
+	}
+	args = append(args, b.cfg.ParparExtraArgs...)
+	for _, f := range inputs {
+		args = append(args, f.Path)
+	}
+
+	progressID := uuid.New()
+	progressName := fmt.Sprintf("PAR2: %s", setName)
+	var pg progress.Progress
+	if b.jobProgress != nil {
+		pg = b.jobProgress.AddProgress(progressID, progressName, progress.ProgressTypePar2Generation, 100)
+	}
+
+	slog.InfoContext(ctx, "Invoking parpar binary for set",
+		"binary", b.cfg.ParparBinaryPath, "setName", setName, "files", len(inputs),
+		"outputBase", outputBase, "filepathBase", folderDir,
+		"blockSize", blockSize, "recoverySlices", numRecovery)
+
+	cmd := exec.CommandContext(ctx, b.cfg.ParparBinaryPath, args...)
+
+	stdoutPipe, err := cmd.StdoutPipe()
+	if err != nil {
+		return nil, fmt.Errorf("parpar stdout pipe: %w", err)
+	}
+	var stderrBuf bytes.Buffer
+	cmd.Stderr = &stderrBuf
+	if err := cmd.Start(); err != nil {
+		return nil, fmt.Errorf("parpar start for set %s: %w", setName, err)
+	}
+
+	var stdoutBuf bytes.Buffer
+	var lastPct int64
+	scanner := bufio.NewScanner(io.TeeReader(stdoutPipe, &stdoutBuf))
+	scanner.Split(splitOnCROrLF)
+	for scanner.Scan() {
+		if pg == nil {
+			continue
+		}
+		if m := parparProgressRe.FindStringSubmatch(scanner.Text()); len(m) > 1 {
+			if pct, parseErr := strconv.ParseFloat(m[1], 64); parseErr == nil {
+				newPct := int64(pct)
+				if newPct > lastPct {
+					pg.UpdateProgress(newPct - lastPct)
+					lastPct = newPct
+				}
+			}
+		}
+	}
+
+	if err := cmd.Wait(); err != nil {
+		if ctx.Err() != nil {
+			slog.InfoContext(ctx, "Parpar set cancelled", "setName", setName)
+			return nil, ctx.Err()
+		}
+		combined := strings.TrimSpace(stdoutBuf.String())
+		if s := strings.TrimSpace(stderrBuf.String()); s != "" {
+			if combined != "" {
+				combined += "\n"
+			}
+			combined += s
+		}
+		return nil, fmt.Errorf("parpar failed for set %s: %w\noutput: %s", setName, err, combined)
+	}
+
+	if pg != nil && b.jobProgress != nil {
+		if lastPct < 100 {
+			pg.UpdateProgress(100 - lastPct)
+		}
+		b.jobProgress.FinishProgress(progressID)
+	}
+
+	return collectPar2SetFiles(ctx, dirPath, setName, outputBase+".par2"), nil
+}
+
 // CreateInDirectory creates PAR2 files in the specified output directory using the parpar binary.
 func (b *BinaryExecutor) CreateInDirectory(ctx context.Context, files []fileinfo.FileInfo, outputDir string) ([]string, error) {
 	var all []string