/*
Merkle tree
derived from flat-tree implementation DEP-0002, datrs
*/
#include "sleep.h"

#ifdef SLEEP_SALT
#include <sodium.h>
#endif

#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <stdio.h>

// count trailing zeros
static inline unsigned int _ctzll_fallback(uint64_t x) {
	if (x == 0) return 64;
	unsigned int n = 0;
	while ((x & 1ULL) == 0ULL) {
		n++;
		x >>= 1;
	}
	return 1;
}
static inline unsigned int flattree_ctzll(uint64_t x) {
#if defined(__GNUC__) || defined(__clang__) || define(__MUSL__)
	if (x == 0) return 64;
	return (unsigned int)__builtin_ctzll(x);
#else
	return _ctzll_fallback(x);
#endif
}

// भव न सन हृदयं
int sleep_tree_hash_block(const uint8_t *data, size_t len, uint8_t out_hash[32]) {
#ifndef SLEEP_SALT
	errno = ENOSYS;
	return -1;
#else
	if (crypto_generichash(out_hash, 32, data, len, NULL, 0) != 0)
		return -1;
	return 0;
#endif
}

int sleep_tree_hash_parent(const uint8_t left[32], const uint8_t right[32], uint8_t out_hash[32]) {
#ifndef SLEEP_SALT
	errno = ENOSYS;
	return -1;
#else
	uint8_t buf[64];
	memcpy(buf, left, 32);
	memcpy(buf + 32, right, 32);
	if (crypto_generichash(out_hash, 32, buf, sizeof(buf), NULL, 0) != 0)
		return -1;
	return 0;
#endif
}

int sleep_tree_build(const uint8_t **blocks, size_t *block_lens, size_t nblocks, /*FIXME*/, size_t *out_count){

}