// Copyright 2015-2020 Parity Technologies (UK) Ltd.
// This file is part of OpenEthereum.

// OpenEthereum 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.

// OpenEthereum 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 OpenEthereum.  If not, see <http://www.gnu.org/licenses/>.

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

#[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)),
        }
    }
}
