#include <qpdf/QPDFObject_private.hh>

std::string

QPDFObject::getDescription()

{

    qpdf_offset_t shift = (getTypeCode() == ::ot_dictionary) ? 2

        : (getTypeCode() == ::ot_array)                      ? 1

                                                             : 0;

    if (object_description) {

        switch (object_description->index()) {

        case 0:

            {

                // Simple template string

                auto description = std::get<0>(*object_description);

                if (auto pos = description.find("$OG"); pos != std::string::npos) {

                    description.replace(pos, 3, og.unparse(' '));

                }

                if (auto pos = description.find("$PO"); pos != std::string::npos) {

                    description.replace(pos, 3, std::to_string(parsed_offset + shift));

                }

                return description;

            }

        case 1:

            {

                // QPDF::JSONReactor generated description

                auto j_descr = std::get<1>(*object_description);

                return (

                    *j_descr.input + (j_descr.object.empty() ? "" : ", " + j_descr.object) +

                    " at offset " + std::to_string(parsed_offset));

            }

        case 2:

            {

                // Child object description

                auto j_descr = std::get<2>(*object_description);

                std::string result;

                if (auto p = j_descr.parent.lock()) {

                    result = p->getDescription();

                }

                result += j_descr.static_descr;

                if (auto pos = result.find("$VD"); pos != std::string::npos) {

                    result.replace(pos, 3, j_descr.var_descr);

                }

                return result;

            }

        case 3:

            auto [stream_id, obj_id] = std::get<3>(*object_description);

            std::string result = qpdf ? qpdf->getFilename() : "";

            result += " object stream " + std::to_string(stream_id) + ", object " +

                std::to_string(obj_id) + " 0 at offset " + std::to_string(parsed_offset + shift);

            return result;

        }

    } else if (og.isIndirect()) {

        return "object " + og.unparse(' ');

    }

    return {};

}