use sha2::{Digest, Sha256};
use std::{convert::TryFrom, fmt};

const HASH_BYTES: usize = 32;
#[derive(AbiExample)]
pub struct Hash(pub [u8; HASH_BYTES]);

#[derive(Default)]
pub struct Hasher {
    hasher: Sha256,
}

impl Hasher {
    pub fn hash(&mut self, val: &[u8]) {
        self.hasher.input(val);
    }
    pub fn result(self) -> Hash {
        // At the time of this writing, the sha2 library is stuck on an old version
        // of generic_array (0.9.0). Decouple ourselves with a clone to our version.
        Hash(<[u8; HASH_BYTES]>::try_from(self.hasher.result().as_slice()).unwrap())
    }
}

impl fmt::Display for Hash {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{}", bs58::encode(self.0).into_string())
    }
}