Remove external dependcy on pdftk about dungeon-sheets HOT 3 OPEN

#!/usr/bin/env python3
from PyPDF4.generic import NameObject
from PyPDF4.generic import TextStringObject
from PyPDF4.pdf import PdfFileReader
from PyPDF4.pdf import PdfFileWriter

import random
import sys

reader = PdfFileReader(sys.argv[1])

writer = PdfFileWriter()
# Try to "clone" the original one (note the library has cloneDocumentFromReader)
# but the render pdf is blank
writer.appendPagesFromReader(reader)
writer._info = reader.trailer["/Info"]
reader_trailer = reader.trailer["/Root"]
writer._root_object.update(
    {
        key: reader_trailer[key]
        for key in reader_trailer
        if key in ("/AcroForm", "/Lang", "/MarkInfo")
    }
)

page = writer.getPage(0)

params = {"Foo": "Bar"}

# Inspired by updatePageFormFieldValues but also handle checkboxes
for annot in page["/Annots"]:
    writer_annot = annot.getObject()
    field = writer_annot["/T"]
    if writer_annot["/FT"] == "/Btn":
        value = params.get(field, random.getrandbits(1))
        if value:
            writer_annot.update(
                {
                    NameObject("/AS"): NameObject("/On"),
                    NameObject("/V"): NameObject("/On"),
                }
            )
    elif writer_annot["/FT"] == "/Tx":
        value = params.get(field, field)
        writer_annot.update(
            {
                NameObject("/V"): TextStringObject(value),
            }
        )

with open(sys.argv[2], "wb") as f:
    writer.write(f)