local immediateobj = pdf.immediateobj
local objectwriter = require'luatagging-objectwriter'
local to_pdf_string = objectwriter.to_pdf_string
local ref = objectwriter.ref

local function late_ref(): objectwriter.Ref, function(objectwriter.PdfObject)
  local objnum = pdf.reserveobj()
  return ref(objnum), function(obj: objectwriter.PdfObject)
    immediateobj(objnum, to_pdf_string(obj))
  end
end

local delayed: {function()} = {}

luatexbase.add_to_callback('finish_pdffile', function()
  for _, f in ipairs(delayed) do
    f()
  end
end, 'luatagging.delayed_pdf')

return {
  late_ref = late_ref,
  delayed = function(f: function(objectwriter.Ref): objectwriter.PdfObject): objectwriter.Ref
    local reference, write = late_ref()
    delayed[#delayed + 1] = function() write(f(reference)) end
    return reference
  end,
  indirect = function(obj: objectwriter.PdfObject): objectwriter.Ref
    return ref(immediateobj(to_pdf_string(obj)))
  end,
  stream = function(dict: objectwriter.Dict, content: string): objectwriter.Ref
    return ref(immediateobj('stream', content, objectwriter.to_pdf_dict_content(dict)))
  end,
}