#pragma once

#include <stdint.h>

#include <array>
#include <string>

typedef struct {
    uint64_t length;
    uint32_t state[8];
    uint32_t curlen;
    uint8_t buf[64];
} Sha256Context;

typedef std::array<uint8_t, 32> Sha256Digest;

//  Initialises a SHA256 Context. Use this to initialise/reset a context.
void sha256Initialise(Sha256Context* Context);

//  Adds data to the SHA256 context. This will process the data and update the
//  internal state of the context. Keep on calling this function until all the
//  data has been added. Then call Sha256Finalise to calculate the hash.
void sha256Update(Sha256Context* Context, void const* Buffer, uint32_t BufferSize);

//  Performs the final calculation of the hash and returns the digest (32 byte
//  buffer containing 256bit hash). After calling this, Sha256Initialised must
//  be used to reuse the context.
void sha256Finalise(Sha256Context* Context, Sha256Digest& Digest);

//  Combines Sha256Initialise, Sha256Update, and Sha256Finalise into one
//  function. Calculates the SHA256 hash of the buffer.
void sha256Calculate(void const* Buffer, uint32_t BufferSize, Sha256Digest& Digest);

//  Converts a SHA256_HASH to a human-readable string.
std::string sha256ToString(const Sha256Digest& Digest);