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use crate::V;
use arrayref::array_ref;
use sha2::{Digest, Sha256};

pub fn hash(left: &V, right: &V) -> V {
    let mut buf = [0u8; 64];
    buf[0..32].copy_from_slice(left);
    buf[32..64].copy_from_slice(right);
    let tmp = Sha256::digest(&buf);
    buf[0..32].copy_from_slice(tmp.as_ref());
    *array_ref![buf, 0, 32]
}

pub fn zero_hash(default: &V, depth: u128) -> V {
    if depth == 0 {
        *default
    } else {
        let h = zero_hash(default, depth - 1);
        hash(array_ref![h, 0, 32], array_ref![h, 0, 32])
    }
}