#ifndef PL_MD5_HH

#define PL_MD5_HH

#include <qpdf/MD5.hh>

#include <qpdf/Pipeline.hh>

#include <qpdf/Util.hh>

// This pipeline sends its output to its successor unmodified.  After calling finish, the MD5

// checksum of the data that passed through the pipeline is available.

//

// This pipeline is reusable; i.e., it is safe to call write() after calling finish().  The first

// call to write() after a call to finish() initializes a new MD5 object.

class Pl_MD5 final: public Pipeline

{

  public:

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

        Pipeline(identifier, next)

    {

    }

    ~Pl_MD5() final = default;

    void write(unsigned char const*, size_t) final;

    void

    finish() final

    {

        if (next()) {

            next()->finish();

        }

        if (!persist_across_finish) {

            in_progress = false;

        }

    }

    std::string

    getHexDigest()

    {

        qpdf::util::assertion(enabled, "digest requested for a disabled MD5 Pipeline");

        in_progress = false;

        return md5.unparse();

    }

    // Enable/disable. Disabling the pipeline causes it to become a pass-through. This makes it

    // possible to stick an MD5 pipeline in a pipeline when it may or may not be required. Disabling

    // it avoids incurring the runtime overhead of doing needless digest computation.

    void

    enable(bool val)

    {

        enabled = val;

    }

    // If persistAcrossFinish is called, calls to finish do not finalize the underlying md5 object.

    // In this case, the object is not finalized until getHexDigest() is called.

    void

    persistAcrossFinish(bool val)

    {

        persist_across_finish = val;

    }

  private:

    bool in_progress{false};

    MD5 md5;

    bool enabled{true};

    bool persist_across_finish{false};

};

#endif // PL_MD5_HH