fix(pdfcpu): switch to CLI

pkg/modules/pdfcpu/pdfcpu.go

@@ -2,11 +2,10 @@ package pdfcpu
 
 import (
 	"context"
+	"errors"
 	"fmt"
+	"os"
 
-	pdfcpuAPI "github.com/pdfcpu/pdfcpu/pkg/api"
-	pdfcpuLog "github.com/pdfcpu/pdfcpu/pkg/log"
-	pdfcpuConfig "github.com/pdfcpu/pdfcpu/pkg/pdfcpu/model"
 	"go.uber.org/zap"
 
 	"github.com/gotenberg/gotenberg/v8/pkg/gotenberg"
@@ -16,10 +15,10 @@ func init() {
 	gotenberg.MustRegisterModule(new(PdfCpu))
 }
 
-// PdfCpu abstracts the pdfcpu library and implements the [gotenberg.PdfEngine]
-// interface.
+// PdfCpu abstracts the CLI tool pdfcpu and implements the
+// [gotenberg.PdfEngine] interface.
 type PdfCpu struct {
-	conf *pdfcpuConfig.Configuration
+	binPath string
 }
 
 // Descriptor returns a [PdfCpu]'s module descriptor.
@@ -32,16 +31,38 @@ func (engine *PdfCpu) Descriptor() gotenberg.ModuleDescriptor {
 
 // Provision sets the engine properties.
 func (engine *PdfCpu) Provision(ctx *gotenberg.Context) error {
-	pdfcpuConfig.ConfigPath = "disable"
-	pdfcpuLog.DisableLoggers()
-	engine.conf = pdfcpuConfig.NewDefaultConfiguration()
+	binPath, ok := os.LookupEnv("PDFCPU_BIN_PATH")
+	if !ok {
+		return errors.New("PDFCPU_BIN_PATH environment variable is not set")
+	}
+
+	engine.binPath = binPath
+
+	return nil
+}
+
+// Validate validates the module properties.
+func (engine *PdfCpu) Validate() error {
+	_, err := os.Stat(engine.binPath)
+	if os.IsNotExist(err) {
+		return fmt.Errorf("pdfcpu binary path does not exist: %w", err)
+	}
 
 	return nil
 }
 
 // Merge combines multiple PDFs into a single PDF.
 func (engine *PdfCpu) Merge(ctx context.Context, logger *zap.Logger, inputPaths []string, outputPath string) error {
-	err := pdfcpuAPI.MergeCreateFile(inputPaths, outputPath, false, engine.conf)
+	var args []string
+	args = append(args, "merge", outputPath)
+	args = append(args, inputPaths...)
+
+	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
 	}
@@ -68,5 +89,6 @@ func (engine *PdfCpu) WriteMetadata(ctx context.Context, logger *zap.Logger, met
 var (
 	_ gotenberg.Module      = (*PdfCpu)(nil)
 	_ gotenberg.Provisioner = (*PdfCpu)(nil)
+	_ gotenberg.Validator   = (*PdfCpu)(nil)
 	_ gotenberg.PdfEngine   = (*PdfCpu)(nil)
 )