feat: add 7.x source code

pkg/modules/pdftk/pdftk.go

@@ -0,0 +1,84 @@
+package pdftk
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+
+	"github.com/gotenberg/gotenberg/v7/pkg/gotenberg"
+	"go.uber.org/zap"
+)
+
+func init() {
+	gotenberg.MustRegisterModule(PDFtk{})
+}
+
+// PDFtk abstracts the CLI tool PDFtk and implements the gotenberg.PDFEngine
+// interface.
+type PDFtk struct {
+	binPath string
+}
+
+// Descriptor returns a PDFtk's module descriptor.
+func (engine PDFtk) Descriptor() gotenberg.ModuleDescriptor {
+	return gotenberg.ModuleDescriptor{
+		ID:  "pdftk",
+		New: func() gotenberg.Module { return new(PDFtk) },
+	}
+}
+
+// Provision sets the modules properties. It returns an error if the
+// environment variable PDFTK_BIN_PATH is not set.
+func (engine *PDFtk) Provision(_ *gotenberg.Context) error {
+	binPath, ok := os.LookupEnv("PDFTK_BIN_PATH")
+	if !ok {
+		return errors.New("PDFTK_BIN_PATH environment variable is not set")
+	}
+
+	engine.binPath = binPath
+
+	return nil
+}
+
+// Validate validates the module properties.
+func (engine PDFtk) Validate() error {
+	_, err := os.Stat(engine.binPath)
+	if os.IsNotExist(err) {
+		return fmt.Errorf("PDFtk binary path does not exist: %w", err)
+	}
+
+	return nil
+}
+
+// Merge merges the given PDFs into a unique PDF.
+func (engine PDFtk) Merge(ctx context.Context, logger *zap.Logger, inputPaths []string, outputPath string) error {
+	var args []string
+	args = append(args, inputPaths...)
+	args = append(args, "cat", "output", outputPath)
+
+	cmd, err := gotenberg.CommandContext(ctx, logger, engine.binPath, args...)
+	if err != nil {
+		return fmt.Errorf("create command: %w", err)
+	}
+
+	err = cmd.Exec()
+	if err == nil {
+		return nil
+	}
+
+	return fmt.Errorf("merge PDFs with PDFtk: %w", err)
+}
+
+// Convert is not available for this PDF engine.
+func (engine PDFtk) Convert(_ context.Context, _ *zap.Logger, format, _, _ string) error {
+	return fmt.Errorf("convert PDF to '%s' with PDFtk: %w", format, gotenberg.ErrPDFEngineMethodNotAvailable)
+}
+
+// Interface guards.
+var (
+	_ gotenberg.Module      = (*PDFtk)(nil)
+	_ gotenberg.Provisioner = (*PDFtk)(nil)
+	_ gotenberg.Validator   = (*PDFtk)(nil)
+	_ gotenberg.PDFEngine   = (*PDFtk)(nil)
+)