use U256;

#[cfg(feature="serialize")]
use serde::{Serialize, Serializer, Deserialize, Deserializer};

#[cfg(feature="serialize")]
use ethereum_types_serialize;

construct_hash!(H32, 4);
construct_hash!(H64, 8);
construct_hash!(H128, 16);
construct_hash!(H160, 20);
construct_hash!(H256, 32);
construct_hash!(H264, 33);
construct_hash!(H512, 64);
construct_hash!(H520, 65);
construct_hash!(H1024, 128);

impl From<U256> for H256 {
	fn from(value: U256) -> H256 {
		let mut ret = H256::new();
		value.to_big_endian(&mut ret);
		ret
	}
}

impl<'a> From<&'a U256> for H256 {
	fn from(value: &'a U256) -> H256 {
		let mut ret: H256 = H256::new();
		value.to_big_endian(&mut ret);
		ret
	}
}

impl From<H256> for U256 {
	fn from(value: H256) -> U256 {
		U256::from(&value)
	}
}

impl<'a> From<&'a H256> for U256 {
	fn from(value: &'a H256) -> U256 {
		U256::from(value.as_ref() as &[u8])
	}
}

impl From<H256> for H160 {
	fn from(value: H256) -> H160 {
		let mut ret = H160::new();
		ret.0.copy_from_slice(&value[12..32]);
		ret
	}
}

impl From<H256> for H64 {
	fn from(value: H256) -> H64 {
		let mut ret = H64::new();
		ret.0.copy_from_slice(&value[20..28]);
		ret
	}
}

impl From<H160> for H256 {
	fn from(value: H160) -> H256 {
		let mut ret = H256::new();
		ret.0[12..32].copy_from_slice(&value);
		ret
	}
}

impl<'a> From<&'a H160> for H256 {
	fn from(value: &'a H160) -> H256 {
		let mut ret = H256::new();
		ret.0[12..32].copy_from_slice(value);
		ret
	}
}

macro_rules! impl_serde {
	($name: ident, $len: expr) => {
		#[cfg(feature="serialize")]
		impl Serialize for $name {
			fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where S: Serializer {
				ethereum_types_serialize::serialize(&self.0, serializer)
			}
		}

		#[cfg(feature="serialize")]
		impl<'de> Deserialize<'de> for $name {
			fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> where D: Deserializer<'de> {
                let mut bytes = [0u8; $len];
				ethereum_types_serialize::deserialize_check_len(deserializer, ethereum_types_serialize::ExpectedLen::Exact(&mut bytes))?;
                Ok($name(bytes))
			}
		}
	}
}

impl_serde!(H32, 4);
impl_serde!(H64, 8);
impl_serde!(H128, 16);
impl_serde!(H160, 20);
impl_serde!(H256, 32);
impl_serde!(H264, 33);
impl_serde!(H512, 64);
impl_serde!(H520, 65);
impl_serde!(H1024, 128);