// 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 std::{fmt, ptr};

#[derive(Clone, PartialEq, Eq, Serialize, Deserialize)]
pub struct Password(String);

impl fmt::Debug for Password {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "Password(******)")
    }
}

impl Password {
    pub fn as_bytes(&self) -> &[u8] {
        self.0.as_bytes()
    }

    pub fn as_str(&self) -> &str {
        self.0.as_str()
    }
}

// Custom drop impl to zero out memory.
impl Drop for Password {
    fn drop(&mut self) {
        unsafe {
            for byte_ref in self.0.as_mut_vec() {
                ptr::write_volatile(byte_ref, 0)
            }
        }
    }
}

impl From<String> for Password {
    fn from(s: String) -> Password {
        Password(s)
    }
}

impl<'a> From<&'a str> for Password {
    fn from(s: &'a str) -> Password {
        Password::from(String::from(s))
    }
}
