#include <qpdf/Pl_ASCIIHexDecoder.hh>

#include <qpdf/QTC.hh>

#include <cctype>

#include <stdexcept>

using namespace std::literals;

Pl_ASCIIHexDecoder::Pl_ASCIIHexDecoder(char const* identifier, Pipeline* next) :

    Pipeline(identifier, next)

{

    if (!next) {

        throw std::logic_error("Attempt to create Pl_ASCIIHexDecoder with nullptr as next");

    }

}

void

Pl_ASCIIHexDecoder::write(unsigned char const* buf, size_t len)

{

    if (eod) {

        return;

    }

    for (size_t i = 0; i < len; ++i) {

        char ch = static_cast<char>(toupper(buf[i]));

        switch (ch) {

        case ' ':

        case '\f':

        case '\v':

        case '\t':

        case '\r':

        case '\n':

            QTC::TC("libtests", "Pl_ASCIIHexDecoder ignore space");

            // ignore whitespace

            break;

        case '>':

            eod = true;

            flush();

            break;

        default:

            if ((ch >= '0' && ch <= '9') || (ch >= 'A' && ch <= 'F')) {

                inbuf[pos++] = ch;

                if (pos == 2) {

                    flush();

                }

            } else {

                char t[2];

                t[0] = ch;

                t[1] = 0;

                throw std::runtime_error("character out of range during base Hex decode: "s + t);

            }

            break;

        }

        if (eod) {

            break;

        }

    }

}

void

Pl_ASCIIHexDecoder::flush()

{

    if (pos == 0) {

        QTC::TC("libtests", "Pl_ASCIIHexDecoder no-op flush");

        return;

    }

    int b[2];

    for (int i = 0; i < 2; ++i) {

        if (inbuf[i] >= 'A') {

            b[i] = inbuf[i] - 'A' + 10;

        } else {

            b[i] = inbuf[i] - '0';

        }

    }

    auto ch = static_cast<unsigned char>((b[0] << 4) + b[1]);

    QTC::TC("libtests", "Pl_ASCIIHexDecoder partial flush", (pos == 2) ? 0 : 1);

    // Reset before calling getNext()->write in case that throws an exception.

    pos = 0;

    inbuf[0] = '0';

    inbuf[1] = '0';

    inbuf[2] = '\0';

    next()->write(&ch, 1);

}

void

Pl_ASCIIHexDecoder::finish()

{

    flush();

    next()->finish();

}