#include <cstdlib>
#include <iostream>

#include <qpdf/QIntC.hh>
#include <qpdf/QPDF.hh>
#include <qpdf/QPDFPageDocumentHelper.hh>
#include <qpdf/QPDFPageObjectHelper.hh>
#include <qpdf/QUtil.hh>

static char const* whoami = nullptr;

void
usage()
{
    std::cerr << "Usage: " << whoami << " filename page-number" << std::endl
              << "Prints a dump of the objects in the content streams of the given page."
              << std::endl
              << "Pages are numbered from 1." << std::endl;
    exit(2);
}

class ParserCallbacks: public QPDFObjectHandle::ParserCallbacks
{
  public:
    ~ParserCallbacks() override = default;
    void contentSize(size_t) override;
    void handleObject(QPDFObjectHandle, size_t offset, size_t length) override;
    void handleEOF() override;
};

void
ParserCallbacks::contentSize(size_t size)
{
    std::cout << "content size: " << size << std::endl;
}

void
ParserCallbacks::handleObject(QPDFObjectHandle obj, size_t offset, size_t length)
{
    std::cout << obj.getTypeName() << ", offset=" << offset << ", length=" << length << ": ";
    if (obj.isInlineImage()) {
        std::cout << QUtil::hex_encode(obj.getInlineImageValue()) << std::endl;
    } else {
        std::cout << obj.unparse() << std::endl;
    }
}

void
ParserCallbacks::handleEOF()
{
    std::cout << "-EOF-" << std::endl;
}

int
main(int argc, char* argv[])
{
    whoami = QUtil::getWhoami(argv[0]);

    if (argc != 3) {
        usage();
    }
    char const* filename = argv[1];
    int pageno = QUtil::string_to_int(argv[2]);

    try {
        QPDF pdf;
        pdf.processFile(filename);
        std::vector<QPDFPageObjectHelper> pages = QPDFPageDocumentHelper(pdf).getAllPages();
        if ((pageno < 1) || (QIntC::to_size(pageno) > pages.size())) {
            usage();
        }

        QPDFPageObjectHelper& page = pages.at(QIntC::to_size(pageno - 1));
        ParserCallbacks cb;
        page.parseContents(&cb);
    } catch (std::exception& e) {
        std::cerr << whoami << ": " << e.what() << std::endl;
        exit(2);
    }

    return 0;
}
