package com.itextpdf.samples.sandbox.acroforms;

import com.itextpdf.forms.PdfAcroForm;
import com.itextpdf.forms.fields.PdfFormCreator;
import com.itextpdf.forms.xfa.XfaForm;
import com.itextpdf.kernel.pdf.PdfDocument;
import com.itextpdf.kernel.pdf.PdfReader;

import java.io.File;
import java.io.FileOutputStream;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class ReadXFA {
    public static final String DEST = "./target/xml/xfa_example.xml";

    public static final String SRC = "./src/main/resources/pdfs/xfa_invoice_example.pdf";

    public static void main(String[] args) throws Exception {
        File file = new File(DEST);
        file.getParentFile().mkdirs();

        new ReadXFA().manipulatePdf(DEST);
    }

    protected void manipulatePdf(String dest) throws Exception {
        PdfDocument pdfDoc = new PdfDocument(new PdfReader(SRC));
        PdfAcroForm form = PdfFormCreator.getAcroForm(pdfDoc, true);
        XfaForm xfa = form.getXfaForm();

        // Get XFA data under datasets/data.
        Node node = xfa.getDatasetsNode();
        NodeList list = node.getChildNodes();
        for (int i = 0; i < list.getLength(); i++) {
            if ("data".equals(list.item(i).getLocalName())) {
                node = list.item(i);
                break;
            }
        }

        try (FileOutputStream os = new FileOutputStream(dest)) {
            Transformer transformer = TransformerFactory.newInstance().newTransformer();
            transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
            transformer.setOutputProperty(OutputKeys.INDENT, "yes");
            transformer.transform(new DOMSource(node), new StreamResult(os));
        }

        pdfDoc.close();
    }
}