// Copyright (c) 2014-2019, The Monero Project
// 
// All rights reserved.
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// permitted provided that the following conditions are met:
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// 1. Redistributions of source code must retain the above copyright notice, this list of
//    conditions and the following disclaimer.
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// 2. Redistributions in binary form must reproduce the above copyright notice, this list
//    of conditions and the following disclaimer in the documentation and/or other
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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// Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers

#pragma once

#include <cstdint>
#include <vector>
#include <string>
#include <boost/multiprecision/cpp_int.hpp>
#include "crypto/hash.h"

namespace cryptonote
{
    typedef boost::multiprecision::uint128_t difficulty_type;

    /**
     * @brief checks if a hash fits the given difficulty
     *
     * The hash passes if (hash * difficulty) < 2^256.
     * Phrased differently, if (hash * difficulty) fits without overflow into
     * the least significant 256 bits of the 320 bit multiplication result.
     *
     * @param hash the hash to check
     * @param difficulty the difficulty to check against
     *
     * @return true if valid, else false
     */
    bool check_hash_64(const crypto::hash &hash, uint64_t difficulty);
    uint64_t next_difficulty_64(std::vector<std::uint64_t> timestamps, std::vector<uint64_t> cumulative_difficulties, size_t target_seconds);

    bool check_hash_128(const crypto::hash &hash, difficulty_type difficulty);
    bool check_hash(const crypto::hash &hash, difficulty_type difficulty);
    difficulty_type next_difficulty(std::vector<std::uint64_t> timestamps, std::vector<difficulty_type> cumulative_difficulties, size_t target_seconds);

    std::string hex(difficulty_type v);
}