use sm3::{Digest, Sm3};

use crate::v4::constants::{ACS4_HMAC_SHA256, ACS4_HMAC_SM3};

#[derive(Clone, Copy)]
pub enum SignAlgorithm {
    Sha256,
    Sm3,
}

impl SignAlgorithm {
    pub fn digest(&self, messge: &[u8]) -> String {
        inner_digest(self, messge)
    }

    pub fn hmac_sign(&self, message: &[u8], key: &[u8]) -> Vec<u8> {
        inner_hmac_sign(self, message, key)
    }

    pub fn as_aliyun_name(&self) -> &'static str {
        match self {
            SignAlgorithm::Sha256 => ACS4_HMAC_SHA256,
            SignAlgorithm::Sm3 => ACS4_HMAC_SM3,
        }
    }
}

fn inner_digest(sign_algorithm: &SignAlgorithm, message: &[u8]) -> String {
    match sign_algorithm {
        SignAlgorithm::Sha256 => sha256::digest(message),
        SignAlgorithm::Sm3 => {
            let mut sm3 = Sm3::new();
            sm3.update(&message);
            hex::encode(sm3.finalize().as_slice())
        }
    }
}

fn inner_hmac_sign(sign_algorithm: &SignAlgorithm, message: &[u8], key: &[u8]) -> Vec<u8> {
    match sign_algorithm {
        SignAlgorithm::Sha256 => {
            let mut hsha256 = hmac_sha256::HMAC::new(key);
            hsha256.update(message);
            hsha256.finalize().to_vec()
        }
        SignAlgorithm::Sm3 => hmac_sm3::hmac_sm3(key, message)
    }
}

#[test]
fn test_digest() {
    assert_eq!(
        "a591a6d40bf420404a011733cfb7b190d62c65bf0bcda32b57b277d9ad9f146e",
        SignAlgorithm::Sha256.digest(b"Hello World")
    );
    assert_eq!(
        "77015816143ee627f4fa410b6dad2bdb9fcbdf1e061a452a686b8711a484c5d7",
        SignAlgorithm::Sm3.digest(b"Hello World")
    );
}