// 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 ethereum_types::{Address, H256, U256};
use ethjson;
use hash::KECCAK_NULL_RLP;
use spec::seal::Seal;

/// Genesis components.
pub struct Genesis {
    /// Seal.
    pub seal: Seal,
    /// Difficulty.
    pub difficulty: U256,
    /// Author.
    pub author: Address,
    /// Timestamp.
    pub timestamp: u64,
    /// Parent hash.
    pub parent_hash: H256,
    /// Gas limit.
    pub gas_limit: U256,
    /// Transactions root.
    pub transactions_root: H256,
    /// Receipts root.
    pub receipts_root: H256,
    /// State root.
    pub state_root: Option<H256>,
    /// Gas used.
    pub gas_used: U256,
    /// Extra data.
    pub extra_data: Vec<u8>,
}

impl From<ethjson::spec::Genesis> for Genesis {
    fn from(g: ethjson::spec::Genesis) -> Self {
        Genesis {
            seal: From::from(g.seal),
            difficulty: g.difficulty.into(),
            author: g.author.map_or_else(Address::zero, Into::into),
            timestamp: g.timestamp.map_or(0, Into::into),
            parent_hash: g.parent_hash.map_or_else(H256::zero, Into::into),
            gas_limit: g.gas_limit.into(),
            transactions_root: g
                .transactions_root
                .map_or_else(|| KECCAK_NULL_RLP.clone(), Into::into),
            receipts_root: g
                .receipts_root
                .map_or_else(|| KECCAK_NULL_RLP.clone(), Into::into),
            state_root: g.state_root.map(Into::into),
            gas_used: g.gas_used.map_or_else(U256::zero, Into::into),
            extra_data: g.extra_data.map_or_else(Vec::new, Into::into),
        }
    }
}