// Copyright 2015-2019 Parity Technologies (UK) Ltd.
// This file is part of Parity Ethereum.

// Parity Ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// Parity Ethereum is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with Parity Ethereum.  If not, see <http://www.gnu.org/licenses/>.

use std::fmt;
use serde::{Serialize, Serializer, Deserialize, Deserializer};
use serde::de::{Error as SerdeError, Visitor};
use super::Error;

#[derive(Debug, PartialEq)]
pub enum Version {
	V3,
}

impl Serialize for Version {
	fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
	where S: Serializer {
		match *self {
			Version::V3 => serializer.serialize_u64(3)
		}
	}
}

impl<'a> Deserialize<'a> for Version {
	fn deserialize<D>(deserializer: D) -> Result<Version, D::Error>
	where D: Deserializer<'a> {
		deserializer.deserialize_any(VersionVisitor)
	}
}

struct VersionVisitor;

impl<'a> Visitor<'a> for VersionVisitor {
	type Value = Version;

	fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
		write!(formatter, "a valid key version identifier")
	}

	fn visit_u64<E>(self, value: u64) -> Result<Self::Value, E> where E: SerdeError {
		match value {
			3 => Ok(Version::V3),
			_ => Err(SerdeError::custom(Error::UnsupportedVersion))
		}
	}
}