// Copyright 2019. The Tari Project
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use blake2::Blake2b;
use digest::{consts::U32, Digest};
use tari_crypto::{hash_domain, hashing::DomainSeparatedHasher};
use tari_mmr::{Hash, HashSlice, MerkleMountainRange};

hash_domain!(MmrTestHashDomain, "com.tari.test.base_layer.core.kernel_mmr", 1);
pub type MmrTestHasherBlake256 = DomainSeparatedHasher<Blake2b<U32>, MmrTestHashDomain>;
pub type TestMmr = MerkleMountainRange<MmrTestHasherBlake256, Vec<Hash>>;

pub fn create_mmr(size: usize) -> TestMmr {
    let mut mmr = TestMmr::new(Vec::default());
    for i in 0..size {
        let hash = int_to_hash(i);
        assert!(mmr.push(hash).is_ok());
    }
    mmr
}

pub fn int_to_hash(n: usize) -> Vec<u8> {
    MmrTestHasherBlake256::new().digest(&n.to_le_bytes()).as_ref().to_vec()
}

pub fn combine_hashes(hashe_slices: &[&HashSlice]) -> Hash {
    let hasher = MmrTestHasherBlake256::new();
    hashe_slices
        .iter()
        .fold(hasher, |hasher, h| hasher.chain_update(*h))
        .finalize()
        .as_ref()
        .to_vec()
}