def _print_file()

in export/securedrop_export/print/service.py [0:0]
41 lines of code
11 McCabe index (conditional complexity)

    def _print_file(self, file_to_print: Path):
        """
        Print a file, attempting to convert to a printable format (PDF)
        if the mimetype is not directly printable.

        file_to_print: Path representing absolute path to target file.
        """
        if self._needs_pdf_conversion(file_to_print):
            logger.info("Convert to pdf for printing")

            # Put converted files in a subdirectory out of an abundance
            # of caution. Libreoffice conversion uses a fixed name and will
            # overwrite existing files of the same name. Right now we
            # only send one file at a time, but if we ever batch these files
            # we don't want to overwrite (eg) memo.pdf with memo.docx
            safe_mkdir(file_to_print.parent, "print-pdf")
            printable_folder = file_to_print.parent / "print-pdf"

            # The filename is deterined by LibreOffice - it's the original stem
            # (name minus extension) plus the new extension (.pdf).
            converted_filename = printable_folder / (file_to_print.stem + ".pdf")
            if converted_filename.exists():
                logger.error("Another file by that name exists already.")
                logger.debug(f"{converted_filename} would be overwritten")
                raise ExportException(sdstatus=Status.ERROR_PRINT)

            args: list[str | Path] = [
                "libreoffice",
                "--headless",
                "--safe-mode",
                "--convert-to",
                "pdf",
                "--outdir",
                printable_folder,
                file_to_print,
            ]

            try:
                logger.debug(f"Convert {file_to_print} to {converted_filename} for printing")
                output = subprocess.check_output(args).decode()
                if "Error" in output:
                    # Even on error, libreoffice returns 0, so we need to check
                    # the output, as well as check that the file exists
                    logger.error("Libreoffice headless conversion error")
                    logger.debug(output)
                    raise ExportException(sdstatus=Status.ERROR_PRINT)

            except subprocess.CalledProcessError as e:
                raise ExportException(sdstatus=Status.ERROR_PRINT, sderror=e.output)

            file_to_print = converted_filename

        if not file_to_print.exists():
            logger.error(f"Something went wrong: {file_to_print} not found")
            raise ExportException(sdstatus=Status.ERROR_PRINT)

        logger.info(f"Sending file to printer {self.printer_name}")
        try:
            # We can switch to using libreoffice --pt $printer_cups_name
            # here, and either print directly (headless) or use the GUI
            subprocess.check_call(
                ["xpp", "-P", self.printer_name, file_to_print],
            )
        except subprocess.CalledProcessError as e:
            raise ExportException(sdstatus=Status.ERROR_PRINT, sderror=e.output)

        # This is an addition to ensure that the entire print job is transferred over.
        # If the job is not fully transferred within the timeout window, the user
        # will see an error message.
        self._wait_for_print()