import com.itextpdf.kernel.pdf.*;
import com.itextpdf.kernel.font.*;
import com.itextpdf.io.font.constants.StandardFonts;
import com.itextpdf.forms.*;
import com.itextpdf.forms.fields.*;

import java.io.*;
import java.util.Map;

public class Main {
	public static void main(String args[]) throws IOException {
		PdfDocument pdf = new PdfDocument(
			new PdfReader("f1040.pdf"),
			new PdfWriter("f1040-courier.pdf")
		);

		PdfAcroForm form = PdfAcroForm.getAcroForm(pdf, false);

		PdfFont courier = PdfFontFactory.createFont(StandardFonts.COURIER);
		Map<String, PdfFormField> fields = form.getFormFields();

		for (var entry : fields.entrySet()) {
			// TODO: Try printing original font family and size on field.
			PdfFormField field = entry.getValue();

			PdfFont original_font = field.getFont();
			// System.out.println("Font: " + original_font);

			String original_postscript_name = original_font
				.getFontProgram()
				.getFontNames()
				.getFontName();

			if (original_postscript_name.equals("HelveticaLTStd-Bold")) {
				field.setFont(courier);
			}
		}

		pdf.close();
	}
}