#include "../config.h"
#include "ccan/endian/endian.h"
#include "ccan/short_types/short_types.h"
#include "hash_u5.h"
#include <string.h>

void hash_u5_init(struct hash_u5 *hu5, const char *hrp)
{
    hu5->buf = 0;
    hu5->num_bits = 0;
    sha256_init(&hu5->hash);
    sha256_update(&hu5->hash, hrp, strlen(hrp));
}

void hash_u5(struct hash_u5 *hu5, const u8 *u5, size_t len)
{
    size_t bits = len * 5;

    while (bits) {
        size_t n = 5;

        if (bits < n)
            n = bits;

        hu5->buf <<= n;
        hu5->buf |= (*u5 >> (5-n));
        bits -= n;
        hu5->num_bits += n;

        if (n == 5)
            u5++;

        if (hu5->num_bits >= 32) {
            be32 be32 = cpu_to_be32((u32)(hu5->buf >> (hu5->num_bits-32)));
            sha256_update(&hu5->hash, &be32, sizeof(be32));
            hu5->num_bits -= 32;
        }
    }
}

void hash_u5_done(struct hash_u5 *hu5, struct sha256 *res)
{
    if (hu5->num_bits) {
        be32 be32 = cpu_to_be32((u32)(hu5->buf << (32 - hu5->num_bits)));

        sha256_update(&hu5->hash, &be32, (hu5->num_bits + 7) / 8);
    }
    sha256_done(&hu5->hash, res);
}
