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// 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/>.

//! Indication of how secure the chain is.

use crate::BlockNumber;

/// Indication of how secure the chain is.
#[derive(Debug, PartialEq, Copy, Clone, Hash, Eq)]
pub enum SecurityLevel {
    /// All blocks from genesis to chain head are known to have valid state transitions and PoW.
    FullState,
    /// All blocks from genesis to chain head are known to have a valid PoW.
    FullProofOfWork,
    /// Some recent headers (the argument) are known to have a valid PoW.
    PartialProofOfWork(BlockNumber),
}

impl SecurityLevel {
    /// `true` for `FullPoW`/`FullState`.
    pub fn is_full(&self) -> bool {
        match *self {
            SecurityLevel::FullState | SecurityLevel::FullProofOfWork => true,
            _ => false,
        }
    }
}