#ifndef MD5_HH

#define MD5_HH

#include <qpdf/QPDFCryptoImpl.hh>

#include <qpdf/Types.h>

#include <memory>

#include <string>

class MD5

{

  public:

    typedef unsigned char Digest[16];

    MD5();

    void reset();

    // encodes string and finalizes

    void encodeString(char const* input_string);

    // encodes file and finalizes; offset < 0 reads whole file

    void encodeFile(char const* filename, qpdf_offset_t up_to_offset = -1);

    // appends string to current md5 object

    void appendString(char const* input_string);

    // appends arbitrary data to current md5 object

    void

    encodeDataIncrementally(char const* input_data, size_t len)

    {

        crypto->MD5_update(reinterpret_cast<unsigned char*>(const_cast<char*>(input_data)), len);

    }

    // appends arbitrary data to current md5 object

    void

    encodeDataIncrementally(std::string_view input_data)

    {

        crypto->MD5_update(

            reinterpret_cast<unsigned char*>(const_cast<char*>(input_data.data())),

            input_data.size());

    }

    // computes a raw digest

    void digest(Digest);

    std::string digest();

    static std::string digest(std::string_view data);

    // prints the digest to stdout terminated with \r\n (primarily for testing)

    void print();

    // returns the digest as a hexadecimal string

    std::string unparse();

    // Convenience functions

    static std::string getDataChecksum(char const* buf, size_t len);

    static std::string getFileChecksum(char const* filename, qpdf_offset_t up_to_offset = -1);

    static bool checkDataChecksum(char const* const checksum, char const* buf, size_t len);

    static bool checkFileChecksum(

        char const* const checksum, char const* filename, qpdf_offset_t up_to_offset = -1);

  private:

    void init();

    void finalize();

    std::shared_ptr<QPDFCryptoImpl> crypto;

};

#endif // MD5_HH