#pragma once
#include <stdint.h>
#include <stddef.h>

// SHA256 round constants (shared across implementations)
extern const uint32_t K[64];

// Initial hash values
static const uint32_t H0[8] = {
    0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
    0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19
};

// Transform one 64-byte block, updating state[8]
typedef void (*TransformFunc)(uint32_t* state, const uint8_t* block);

// Detect best available implementation at runtime
TransformFunc detect_best_transform(void);

// Generic C implementation (always available)
void transform_generic(uint32_t* state, const uint8_t* block);