#include <qpdf/Pl_MD5.hh>

#include <stdexcept>

Pl_MD5::Pl_MD5(char const* identifier, Pipeline* next) :

    Pipeline(identifier, next)

{

    if (!next) {

        throw std::logic_error("Attempt to create Pl_MD5 with nullptr as next");

    }

}

void

Pl_MD5::write(unsigned char const* buf, size_t len)

{

    if (enabled) {

        if (!in_progress) {

            md5.reset();

            in_progress = true;

        }

        // Write in chunks in case len is too big to fit in an int. Assume int is at least 32 bits.

        static size_t const max_bytes = 1 << 30;

        size_t bytes_left = len;

        unsigned char const* data = buf;

        while (bytes_left > 0) {

            size_t bytes = (bytes_left >= max_bytes ? max_bytes : bytes_left);

            md5.encodeDataIncrementally(reinterpret_cast<char const*>(data), bytes);

            bytes_left -= bytes;

            data += bytes;

        }

    }

    next()->write(buf, len);

}

void

Pl_MD5::finish()

{

    next()->finish();

    if (!persist_across_finish) {

        in_progress = false;

    }

}

void

Pl_MD5::enable(bool is_enabled)

{

    enabled = is_enabled;

}

void

Pl_MD5::persistAcrossFinish(bool persist)

{

    persist_across_finish = persist;

}

std::string

Pl_MD5::getHexDigest()

{

    if (!enabled) {

        throw std::logic_error("digest requested for a disabled MD5 Pipeline");

    }

    in_progress = false;

    return md5.unparse();

}