feat(pdfengines): add split feature

pkg/modules/pdfcpu/pdfcpu.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"os"
+	"path/filepath"
 
 	"go.uber.org/zap"
 
@@ -70,6 +71,38 @@ func (engine *PdfCpu) Merge(ctx context.Context, logger *zap.Logger, inputPaths
 	return fmt.Errorf("merge PDFs with pdfcpu: %w", err)
 }
 
+// Split splits a given PDF file.
+func (engine *PdfCpu) Split(ctx context.Context, logger *zap.Logger, mode gotenberg.SplitMode, inputPath, outputDirPath string) ([]string, error) {
+	var args []string
+
+	switch mode.Mode {
+	case gotenberg.SplitModeIntervals:
+		args = append(args, "split", "-mode", "span", inputPath, outputDirPath, mode.Span)
+	case gotenberg.SplitModePages:
+		outputPath := fmt.Sprintf("%s/%s", outputDirPath, filepath.Base(inputPath))
+		args = append(args, "trim", "-pages", mode.Span, inputPath, outputPath)
+	default:
+		return nil, fmt.Errorf("split PDFs using mode '%s' with pdfcpu: %w", mode.Mode, gotenberg.ErrPdfSplitModeNotSupported)
+	}
+
+	cmd, err := gotenberg.CommandContext(ctx, logger, engine.binPath, args...)
+	if err != nil {
+		return nil, fmt.Errorf("create command: %w", err)
+	}
+
+	_, err = cmd.Exec()
+	if err != nil {
+		return nil, fmt.Errorf("split PDFs with pdfcpu: %w", err)
+	}
+
+	outputPaths, err := gotenberg.WalkDir(outputDirPath, ".pdf")
+	if err != nil {
+		return nil, fmt.Errorf("walk directory to find resulting PDFs from split with pdfcpu: %w", err)
+	}
+
+	return outputPaths, nil
+}
+
 // Convert is not available in this implementation.
 func (engine *PdfCpu) Convert(ctx context.Context, logger *zap.Logger, formats gotenberg.PdfFormats, inputPath, outputPath string) error {
 	return fmt.Errorf("convert PDF to '%+v' with pdfcpu: %w", formats, gotenberg.ErrPdfEngineMethodNotSupported)