// 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/>.

//! Unique identifiers.

use crate::BlockNumber;
use ethereum_types::H256;

/// Uniquely identifies block.
#[derive(Debug, PartialEq, Copy, Clone, Hash, Eq)]
pub enum BlockId {
    /// Block's sha3.
    /// Querying by hash is always faster.
    Hash(H256),
    /// Block number within canon blockchain.
    Number(BlockNumber),
    /// Earliest block (genesis).
    Earliest,
    /// Latest mined block.
    Latest,
}

/// Uniquely identifies transaction.
#[derive(Debug, PartialEq, Clone, Hash, Eq)]
pub enum TransactionId {
    /// Transaction's sha3.
    Hash(H256),
    /// Block id and transaction index within this block.
    /// Querying by block position is always faster.
    Location(BlockId, usize),
}

/// Uniquely identifies Trace.
pub struct TraceId {
    /// Transaction
    pub transaction: TransactionId,
    /// Trace address within transaction.
    pub address: Vec<usize>,
}

/// Uniquely identifies Uncle.
#[derive(Debug, PartialEq, Eq, Copy, Clone)]
pub struct UncleId {
    /// Block id.
    pub block: BlockId,
    /// Position in block.
    pub position: usize,
}
