// 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/>.

//! Eth rpc implementation.

use std::{
    sync::Arc,
    thread,
    time::{Duration, Instant, SystemTime, UNIX_EPOCH},
};

use ethereum_types::{Address, BigEndianHash, H160, H256, H64, U256, U64};
use parking_lot::Mutex;

use ethash::{self, SeedHashCompute};
use ethcore::{
    client::{
        BlockChainClient, BlockId, Call, EngineInfo, ProvingBlockChainClient, StateClient,
        StateInfo, StateOrBlock, TransactionId, UncleId,
    },
    miner::{self, MinerService},
    snapshot::SnapshotService,
};
use hash::keccak;
use miner::external::ExternalMinerService;
use sync::SyncProvider;
use types::{
    encoded,
    filter::Filter as EthcoreFilter,
    header::Header,
    transaction::{LocalizedTransaction, SignedTransaction, TypedTransaction},
    BlockNumber as EthBlockNumber,
};

use jsonrpc_core::{futures::future, BoxFuture, Result};

use v1::{
    helpers::{
        self,
        block_import::is_major_importing,
        deprecated::{self, DeprecationNotice},
        dispatch::{default_gas_price, FullDispatcher},
        errors, fake_sign, limit_logs,
    },
    metadata::Metadata,
    traits::Eth,
    types::{
        block_number_to_id, Block, BlockNumber, BlockTransactions, Bytes, CallRequest, EthAccount,
        Filter, Index, Log, Receipt, RichBlock, StorageProof, SyncInfo, SyncStatus, Transaction,
        Work,
    },
};

const EXTRA_INFO_PROOF: &str = "Object exists in blockchain (fetched earlier), extra_info is always available if object exists; qed";

/// Eth RPC options
#[derive(Copy, Clone)]
pub struct EthClientOptions {
    /// Gas Price Percentile used as default gas price.
    pub gas_price_percentile: usize,
    /// Return 'null' instead of an error if ancient block sync is still in
    /// progress and the block information requested could not be found.
    pub allow_missing_blocks: bool,
    /// Enable Experimental RPC-Calls
    pub allow_experimental_rpcs: bool,
    /// flag for ancient block sync
    pub no_ancient_blocks: bool,
}

impl EthClientOptions {
    /// Creates new default `EthClientOptions` and allows alterations
    /// by provided function.
    pub fn with<F: Fn(&mut Self)>(fun: F) -> Self {
        let mut options = Self::default();
        fun(&mut options);
        options
    }
}

impl Default for EthClientOptions {
    fn default() -> Self {
        EthClientOptions {
            gas_price_percentile: 50,
            allow_missing_blocks: false,
            allow_experimental_rpcs: false,
            no_ancient_blocks: false,
        }
    }
}

/// Eth rpc implementation.
pub struct EthClient<C, SN: ?Sized, S: ?Sized, M, EM>
where
    C: miner::BlockChainClient + BlockChainClient,
    SN: SnapshotService,
    S: SyncProvider,
    M: MinerService,
    EM: ExternalMinerService,
{
    client: Arc<C>,
    snapshot: Arc<SN>,
    sync: Arc<S>,
    accounts: Arc<dyn Fn() -> Vec<Address> + Send + Sync>,
    miner: Arc<M>,
    external_miner: Arc<EM>,
    seed_compute: Mutex<SeedHashCompute>,
    options: EthClientOptions,
    deprecation_notice: DeprecationNotice,
}

#[derive(Debug)]
enum BlockNumberOrId {
    Number(BlockNumber),
    Id(BlockId),
}

impl From<BlockId> for BlockNumberOrId {
    fn from(value: BlockId) -> BlockNumberOrId {
        BlockNumberOrId::Id(value)
    }
}

impl From<BlockNumber> for BlockNumberOrId {
    fn from(value: BlockNumber) -> BlockNumberOrId {
        BlockNumberOrId::Number(value)
    }
}

enum PendingOrBlock {
    Block(BlockId),
    Pending,
}

struct PendingUncleId {
    id: PendingOrBlock,
    position: usize,
}

enum PendingTransactionId {
    Hash(H256),
    Location(PendingOrBlock, usize),
}

impl<C, SN: ?Sized, S: ?Sized, M, EM, T: StateInfo + 'static> EthClient<C, SN, S, M, EM>
where
    C: miner::BlockChainClient
        + BlockChainClient
        + StateClient<State = T>
        + Call<State = T>
        + EngineInfo,
    SN: SnapshotService,
    S: SyncProvider,
    M: MinerService<State = T>,
    EM: ExternalMinerService,
{
    /// Creates new EthClient.
    pub fn new(
        client: &Arc<C>,
        snapshot: &Arc<SN>,
        sync: &Arc<S>,
        accounts: &Arc<dyn Fn() -> Vec<Address> + Send + Sync>,
        miner: &Arc<M>,
        em: &Arc<EM>,
        options: EthClientOptions,
    ) -> Self {
        EthClient {
            client: client.clone(),
            snapshot: snapshot.clone(),
            sync: sync.clone(),
            miner: miner.clone(),
            accounts: accounts.clone(),
            external_miner: em.clone(),
            seed_compute: Mutex::new(SeedHashCompute::default()),
            options,
            deprecation_notice: Default::default(),
        }
    }

    fn rich_block(&self, id: BlockNumberOrId, include_txs: bool) -> Result<Option<RichBlock>> {
        let client = &self.client;

        let client_query = |id| {
            (
                client.block(id),
                client.block_total_difficulty(id),
                client.block_extra_info(id),
                false,
            )
        };

        let (block, difficulty, extra, is_pending) = match id {
            BlockNumberOrId::Number(BlockNumber::Pending) => {
                let info = self.client.chain_info();
                match self.miner.pending_block(info.best_block_number) {
                    Some(pending_block) => {
                        warn!("`Pending` is deprecated and may be removed in future versions.");

                        let difficulty = {
                            let latest_difficulty = self
                                .client
                                .block_total_difficulty(BlockId::Latest)
                                .expect("blocks in chain have details; qed");
                            let pending_difficulty = self
                                .miner
                                .pending_block_header(info.best_block_number)
                                .map(|header| *header.difficulty());

                            if let Some(difficulty) = pending_difficulty {
                                difficulty + latest_difficulty
                            } else {
                                latest_difficulty
                            }
                        };

                        let extra = self.client.engine().extra_info(&pending_block.header);

                        (
                            Some(encoded::Block::new(pending_block.rlp_bytes())),
                            Some(difficulty),
                            Some(extra),
                            true,
                        )
                    }
                    None => {
                        warn!("`Pending` is deprecated and may be removed in future versions. Falling back to `Latest`");
                        client_query(BlockId::Latest)
                    }
                }
            }

            BlockNumberOrId::Number(num) => {
                let id = match num {
                    BlockNumber::Hash { hash, .. } => BlockId::Hash(hash),
                    BlockNumber::Latest => BlockId::Latest,
                    BlockNumber::Earliest => BlockId::Earliest,
                    BlockNumber::Num(n) => BlockId::Number(n),
                    BlockNumber::Pending => unreachable!(), // Already covered
                };

                client_query(id)
            }

            BlockNumberOrId::Id(id) => client_query(id),
        };

        match (block, difficulty) {
            (Some(block), Some(total_difficulty)) => {
                let view = block.header_view();
                let eip1559_enabled = client.engine().schedule(view.number()).eip1559;
                let base_fee = if eip1559_enabled {
                    Some(view.base_fee())
                } else {
                    None
                };
                Ok(Some(RichBlock {
                    inner: Block {
                        hash: match is_pending {
                            true => None,
                            false => Some(view.hash()),
                        },
                        size: Some(block.rlp().as_raw().len().into()),
                        parent_hash: view.parent_hash(),
                        uncles_hash: view.uncles_hash(),
                        author: view.author(),
                        miner: view.author(),
                        state_root: view.state_root(),
                        transactions_root: view.transactions_root(),
                        receipts_root: view.receipts_root(),
                        number: match is_pending {
                            true => None,
                            false => Some(view.number().into()),
                        },
                        gas_used: view.gas_used(),
                        gas_limit: view.gas_limit(),
                        logs_bloom: match is_pending {
                            true => None,
                            false => Some(view.log_bloom()),
                        },
                        timestamp: view.timestamp().into(),
                        difficulty: view.difficulty(),
                        total_difficulty: Some(total_difficulty),
                        seal_fields: view
                            .seal(eip1559_enabled)
                            .into_iter()
                            .map(Into::into)
                            .collect(),
                        base_fee_per_gas: base_fee,
                        uncles: block.uncle_hashes(),
                        transactions: match include_txs {
                            true => BlockTransactions::Full(
                                block
                                    .view()
                                    .localized_transactions()
                                    .into_iter()
                                    .map(|t| Transaction::from_localized(t, base_fee))
                                    .collect(),
                            ),
                            false => BlockTransactions::Hashes(block.transaction_hashes()),
                        },
                        extra_data: Bytes::new(view.extra_data()),
                    },
                    extra_info: extra.expect(EXTRA_INFO_PROOF),
                }))
            }
            _ => Ok(None),
        }
    }

    fn transaction(&self, id: PendingTransactionId) -> Result<Option<Transaction>> {
        let client_transaction = |id| match self.client.block_transaction(id) {
            Some(t) => {
                let block = self
                    .rich_block(BlockNumber::Num(t.block_number).into(), false)
                    .and_then(errors::check_block_number_existence(
                        &*self.client,
                        BlockNumber::Num(t.block_number).into(),
                        self.options,
                    ));
                let base_fee = match block {
                    Ok(block) => match block {
                        Some(block) => block.base_fee_per_gas,
                        None => return Ok(None),
                    },
                    Err(_) => return Ok(None),
                };
                Ok(Some(Transaction::from_localized(t, base_fee)))
            }
            None => Ok(None),
        };

        match id {
            PendingTransactionId::Hash(hash) => client_transaction(TransactionId::Hash(hash)),

            PendingTransactionId::Location(PendingOrBlock::Block(block), index) => {
                client_transaction(TransactionId::Location(block, index))
            }

            PendingTransactionId::Location(PendingOrBlock::Pending, index) => {
                let info = self.client.chain_info();
                let pending_block = match self.miner.pending_block(info.best_block_number) {
                    Some(block) => block,
                    None => return Ok(None),
                };

                // Implementation stolen from `extract_transaction_at_index`
                let transaction = pending_block
                    .transactions
                    .get(index)
                    // Verify if transaction signature is correct.
                    .and_then(|tx| SignedTransaction::new(tx.clone()).ok())
                    .map(|signed_tx| {
                        let (signed, sender, _) = signed_tx.deconstruct();
                        let block_hash = pending_block.header.hash();
                        let block_number = pending_block.header.number();
                        let transaction_index = index;
                        let cached_sender = Some(sender);

                        LocalizedTransaction {
                            signed,
                            block_number,
                            block_hash,
                            transaction_index,
                            cached_sender,
                        }
                    })
                    .map(|t| Transaction::from_localized(t, pending_block.header.base_fee()));

                Ok(transaction)
            }
        }
    }

    fn uncle(&self, id: PendingUncleId) -> Result<Option<RichBlock>> {
        let client = &self.client;

        let (uncle, parent_difficulty, extra) = match id {
            PendingUncleId {
                id: PendingOrBlock::Pending,
                position,
            } => {
                let info = self.client.chain_info();

                let pending_block = match self.miner.pending_block(info.best_block_number) {
                    Some(block) => block,
                    None => return Ok(None),
                };

                let uncle = match pending_block.uncles.get(position) {
                    Some(uncle) => uncle.clone(),
                    None => return Ok(None),
                };

                let difficulty = {
                    let latest_difficulty = self
                        .client
                        .block_total_difficulty(BlockId::Latest)
                        .expect("blocks in chain have details; qed");
                    let pending_difficulty = self
                        .miner
                        .pending_block_header(info.best_block_number)
                        .map(|header| *header.difficulty());

                    if let Some(difficulty) = pending_difficulty {
                        difficulty + latest_difficulty
                    } else {
                        latest_difficulty
                    }
                };

                let extra = self.client.engine().extra_info(&pending_block.header);

                (uncle, difficulty, extra)
            }

            PendingUncleId {
                id: PendingOrBlock::Block(block_id),
                position,
            } => {
                let uncle_id = UncleId {
                    block: block_id,
                    position,
                };

                let uncle = match client.uncle(uncle_id) {
                    Some(hdr) => match hdr.decode(self.client.engine().params().eip1559_transition)
                    {
                        Ok(h) => h,
                        Err(e) => return Err(errors::decode(e)),
                    },
                    None => {
                        return Ok(None);
                    }
                };

                let parent_difficulty =
                    match client.block_total_difficulty(BlockId::Hash(*uncle.parent_hash())) {
                        Some(difficulty) => difficulty,
                        None => {
                            return Ok(None);
                        }
                    };

                let extra = client.uncle_extra_info(uncle_id).expect(EXTRA_INFO_PROOF);

                (uncle, parent_difficulty, extra)
            }
        };

        let size = client
            .block(BlockId::Hash(uncle.hash()))
            .map(|block| block.into_inner().len())
            .map(U256::from);

        let block = RichBlock {
            inner: Block {
                hash: Some(uncle.hash()),
                size,
                parent_hash: *uncle.parent_hash(),
                uncles_hash: *uncle.uncles_hash(),
                author: *uncle.author(),
                miner: *uncle.author(),
                state_root: *uncle.state_root(),
                transactions_root: *uncle.transactions_root(),
                number: Some(uncle.number().into()),
                gas_used: *uncle.gas_used(),
                gas_limit: *uncle.gas_limit(),
                logs_bloom: Some(*uncle.log_bloom()),
                timestamp: uncle.timestamp().into(),
                difficulty: *uncle.difficulty(),
                total_difficulty: Some(uncle.difficulty() + parent_difficulty),
                receipts_root: *uncle.receipts_root(),
                extra_data: uncle.extra_data().clone().into(),
                seal_fields: uncle.seal().iter().cloned().map(Into::into).collect(),
                base_fee_per_gas: uncle.base_fee(),
                uncles: vec![],
                transactions: BlockTransactions::Hashes(vec![]),
            },
            extra_info: extra,
        };
        Ok(Some(block))
    }

    /// Get state for the given block number. Returns either the State or a block from which state
    /// can be retrieved.
    /// Note: When passing `BlockNumber::Pending` we fall back to the state of the current best block
    /// if no state found for the best pending block.
    fn get_state(&self, number: BlockNumber) -> StateOrBlock {
        match number {
            BlockNumber::Hash { hash, .. } => BlockId::Hash(hash).into(),
            BlockNumber::Num(num) => BlockId::Number(num).into(),
            BlockNumber::Earliest => BlockId::Earliest.into(),
            BlockNumber::Latest => BlockId::Latest.into(),
            BlockNumber::Pending => {
                let info = self.client.chain_info();

                self.miner
					.pending_state(info.best_block_number)
					.map(|s| Box::new(s) as Box<dyn StateInfo>)
					.unwrap_or_else(|| {
						warn!("Asked for best pending state, but none found. Falling back to latest state");
						let (state, _) = self.client.latest_state_and_header();
						Box::new(state) as Box<dyn StateInfo>
					})
					.into()
            }
        }
    }

    /// Get the state and header of best pending block. On failure, fall back to the best imported
    /// blocks state&header.
    fn pending_state_and_header_with_fallback(&self) -> (T, Header) {
        let best_block_number = self.client.chain_info().best_block_number;
        let (maybe_state, maybe_header) = self.miner.pending_state(best_block_number).map_or_else(
            || (None, None),
            |s| (Some(s), self.miner.pending_block_header(best_block_number)),
        );

        match (maybe_state, maybe_header) {
            (Some(state), Some(header)) => (state, header),
            _ => {
                warn!("Falling back to \"Latest\"");
                self.client.latest_state_and_header()
            }
        }
    }
}

pub fn pending_logs<M>(miner: &M, best_block: EthBlockNumber, filter: &EthcoreFilter) -> Vec<Log>
where
    M: MinerService,
{
    let receipts = miner.pending_receipts(best_block).unwrap_or_default();

    receipts
        .into_iter()
        .flat_map(|r| {
            let hash = r.transaction_hash;
            r.logs.into_iter().map(move |l| (hash, l))
        })
        .filter(|pair| filter.matches(&pair.1))
        .map(|pair| {
            let mut log = Log::from(pair.1);
            log.transaction_hash = Some(pair.0);
            log
        })
        .collect()
}

fn check_known<C>(client: &C, number: BlockNumber) -> Result<()>
where
    C: BlockChainClient,
{
    use types::block_status::BlockStatus;

    let id = match number {
        BlockNumber::Pending => return Ok(()),
        BlockNumber::Num(n) => BlockId::Number(n),
        BlockNumber::Latest => BlockId::Latest,
        BlockNumber::Earliest => BlockId::Earliest,
        BlockNumber::Hash {
            hash,
            require_canonical,
        } => {
            // block check takes precedence over canon check.
            match client.block_status(BlockId::Hash(hash.clone())) {
                BlockStatus::InChain => {}
                _ => return Err(errors::unknown_block()),
            };

            if require_canonical && !client.is_canon(&hash) {
                return Err(errors::invalid_input());
            }

            return Ok(());
        }
    };

    match client.block_status(id) {
        BlockStatus::InChain => Ok(()),
        _ => Err(errors::unknown_block()),
    }
}

const MAX_QUEUE_SIZE_TO_MINE_ON: usize = 4; // because uncles go back 6.

impl<C, SN: ?Sized, S: ?Sized, M, EM, T: StateInfo + 'static> Eth for EthClient<C, SN, S, M, EM>
where
    C: miner::BlockChainClient
        + StateClient<State = T>
        + ProvingBlockChainClient
        + Call<State = T>
        + EngineInfo
        + 'static,
    SN: SnapshotService + 'static,
    S: SyncProvider + 'static,
    M: MinerService<State = T> + 'static,
    EM: ExternalMinerService + 'static,
{
    type Metadata = Metadata;

    fn protocol_version(&self) -> Result<String> {
        let version = self.sync.status().protocol_version.to_owned();
        Ok(format!("{}", version))
    }

    fn syncing(&self) -> Result<SyncStatus> {
        use ethcore::snapshot::RestorationStatus;

        let status = self.sync.status();
        let client = &self.client;
        let snapshot_status = self.snapshot.restoration_status();

        let (warping, warp_chunks_amount, warp_chunks_processed) = match snapshot_status {
            RestorationStatus::Ongoing {
                state_chunks,
                block_chunks,
                state_chunks_done,
                block_chunks_done,
                ..
            } => (
                true,
                Some(block_chunks + state_chunks),
                Some(block_chunks_done + state_chunks_done),
            ),
            _ => (false, None, None),
        };

        if warping || is_major_importing(Some(status.state), client.queue_info()) {
            let chain_info = client.chain_info();
            let current_block = U256::from(chain_info.best_block_number);
            let highest_block = U256::from(
                status
                    .highest_block_number
                    .unwrap_or(status.start_block_number),
            );

            let info = SyncInfo {
                starting_block: status.start_block_number.into(),
                current_block,
                highest_block,
                warp_chunks_amount: warp_chunks_amount
                    .map(|x| U256::from(x as u64))
                    .map(Into::into),
                warp_chunks_processed: warp_chunks_processed
                    .map(|x| U256::from(x as u64))
                    .map(Into::into),
            };
            Ok(SyncStatus::Info(info))
        } else {
            Ok(SyncStatus::None)
        }
    }

    fn author(&self) -> Result<H160> {
        let miner = self.miner.authoring_params().author;
        if miner.is_zero() {
            (self.accounts)()
                .first()
                .cloned()
                .ok_or_else(|| errors::account("No accounts were found", ""))
        } else {
            Ok(miner)
        }
    }

    fn is_mining(&self) -> Result<bool> {
        Ok(self.miner.is_currently_sealing())
    }

    fn chain_id(&self) -> Result<Option<U64>> {
        Ok(self.client.signing_chain_id().map(U64::from))
    }

    fn hashrate(&self) -> Result<U256> {
        Ok(self.external_miner.hashrate())
    }

    fn gas_price(&self) -> BoxFuture<U256> {
        Box::new(future::ok(default_gas_price(
            &*self.client,
            &*self.miner,
            self.options.gas_price_percentile,
        )))
    }

    fn accounts(&self) -> Result<Vec<H160>> {
        self.deprecation_notice
            .print("eth_accounts", deprecated::msgs::ACCOUNTS);

        let accounts = (self.accounts)();
        Ok(accounts)
    }

    fn block_number(&self) -> Result<U256> {
        Ok(U256::from(self.client.chain_info().best_block_number))
    }

    fn balance(&self, address: H160, num: Option<BlockNumber>) -> BoxFuture<U256> {
        let num = num.unwrap_or_default();

        try_bf!(check_known(&*self.client, num.clone()));
        let res = self
            .client
            .balance(&address, self.get_state(num))
            .ok_or_else(|| errors::state_pruned());

        Box::new(future::done(res))
    }

    fn proof(
        &self,
        address: H160,
        values: Vec<H256>,
        num: Option<BlockNumber>,
    ) -> BoxFuture<EthAccount> {
        try_bf!(errors::require_experimental(
            self.options.allow_experimental_rpcs,
            "1186"
        ));

        let key1 = keccak(address);

        let num = num.unwrap_or_default();
        let id = match num {
            BlockNumber::Hash { hash, .. } => BlockId::Hash(hash),
            BlockNumber::Num(n) => BlockId::Number(n),
            BlockNumber::Earliest => BlockId::Earliest,
            BlockNumber::Latest => BlockId::Latest,
            BlockNumber::Pending => {
                self.deprecation_notice
                    .print("`Pending`", Some("falling back to `Latest`"));
                BlockId::Latest
            }
        };

        try_bf!(check_known(&*self.client, num.clone()));
        let res = match self.client.prove_account(key1, id) {
            Some((proof, account)) => Ok(EthAccount {
                address,
                balance: account.balance,
                nonce: account.nonce,
                code_hash: account.code_hash,
                storage_hash: account.storage_root,
                account_proof: proof.into_iter().map(Bytes::new).collect(),
                storage_proof: values
                    .into_iter()
                    .filter_map(|storage_index| {
                        let key2: H256 = storage_index;
                        self.client.prove_storage(key1, keccak(key2), id).map(
                            |(storage_proof, storage_value)| StorageProof {
                                key: key2.into_uint(),
                                value: storage_value.into_uint(),
                                proof: storage_proof.into_iter().map(Bytes::new).collect(),
                            },
                        )
                    })
                    .collect::<Vec<StorageProof>>(),
            }),
            None => Err(errors::state_pruned()),
        };

        Box::new(future::done(res))
    }

    fn storage_at(
        &self,
        address: H160,
        position: U256,
        num: Option<BlockNumber>,
    ) -> BoxFuture<H256> {
        let num = num.unwrap_or_default();

        try_bf!(check_known(&*self.client, num.clone()));
        let res = match self.client.storage_at(
            &address,
            &BigEndianHash::from_uint(&position),
            self.get_state(num),
        ) {
            Some(s) => Ok(s),
            None => Err(errors::state_pruned()),
        };

        Box::new(future::done(res))
    }

    fn transaction_count(&self, address: H160, num: Option<BlockNumber>) -> BoxFuture<U256> {
        let res = match num.unwrap_or_default() {
            BlockNumber::Pending => {
                let info = self.client.chain_info();
                let nonce = self
                    .miner
                    .pending_state(info.best_block_number)
                    .and_then(|s| s.nonce(&address).ok())
                    .or_else(|| {
                        warn!("Fallback to `BlockId::Latest`");
                        self.client.nonce(&address, BlockId::Latest)
                    });

                nonce.ok_or_else(|| errors::database("latest nonce missing"))
            }
            number => {
                try_bf!(check_known(&*self.client, number.clone()));
                self.client
                    .nonce(&address, block_number_to_id(number))
                    .ok_or_else(|| errors::state_pruned())
            }
        };

        Box::new(future::done(res))
    }

    fn block_transaction_count_by_hash(&self, hash: H256) -> BoxFuture<Option<U256>> {
        let trx_count = self
            .client
            .block(BlockId::Hash(hash))
            .map(|block| block.transactions_count().into());
        let result = Ok(trx_count).and_then(errors::check_block_gap(&*self.client, self.options));
        Box::new(future::done(result))
    }

    fn block_transaction_count_by_number(&self, num: BlockNumber) -> BoxFuture<Option<U256>> {
        Box::new(future::done(match num {
            BlockNumber::Pending => Ok(Some(
                self.miner
                    .pending_transaction_hashes(&*self.client)
                    .len()
                    .into(),
            )),
            _ => {
                let trx_count = self
                    .client
                    .block(block_number_to_id(num.clone()))
                    .map(|block| block.transactions_count().into());
                Ok(trx_count).and_then(errors::check_block_number_existence(
                    &*self.client,
                    num,
                    self.options,
                ))
            }
        }))
    }

    fn block_uncles_count_by_hash(&self, hash: H256) -> BoxFuture<Option<U256>> {
        let uncle_count = self
            .client
            .block(BlockId::Hash(hash))
            .map(|block| block.uncles_count().into());
        let result = Ok(uncle_count).and_then(errors::check_block_gap(&*self.client, self.options));
        Box::new(future::done(result))
    }

    fn block_uncles_count_by_number(&self, num: BlockNumber) -> BoxFuture<Option<U256>> {
        Box::new(future::done(match num {
            BlockNumber::Pending => Ok(Some(0.into())),
            _ => {
                let uncles_count = self
                    .client
                    .block(block_number_to_id(num.clone()))
                    .map(|block| block.uncles_count().into());
                Ok(uncles_count).and_then(errors::check_block_number_existence(
                    &*self.client,
                    num,
                    self.options,
                ))
            }
        }))
    }

    fn code_at(&self, address: H160, num: Option<BlockNumber>) -> BoxFuture<Bytes> {
        let address: Address = H160::into(address);

        let num = num.unwrap_or_default();
        try_bf!(check_known(&*self.client, num.clone()));

        let res = match self.client.code(&address, self.get_state(num)) {
            Some(code) => Ok(code.map_or_else(Bytes::default, Bytes::new)),
            None => Err(errors::state_pruned()),
        };

        Box::new(future::done(res))
    }

    fn block_by_hash(&self, hash: H256, include_txs: bool) -> BoxFuture<Option<RichBlock>> {
        let result = self
            .rich_block(BlockId::Hash(hash).into(), include_txs)
            .and_then(errors::check_block_gap(&*self.client, self.options));
        Box::new(future::done(result))
    }

    fn block_by_number(&self, num: BlockNumber, include_txs: bool) -> BoxFuture<Option<RichBlock>> {
        let result = self.rich_block(num.clone().into(), include_txs).and_then(
            errors::check_block_number_existence(&*self.client, num, self.options),
        );
        Box::new(future::done(result))
    }

    fn transaction_by_hash(&self, hash: H256) -> BoxFuture<Option<Transaction>> {
        let tx = try_bf!(self.transaction(PendingTransactionId::Hash(hash))).or_else(|| {
            self.miner
                .transaction(&hash)
                .map(|t| Transaction::from_pending(t.pending().clone()))
        });
        let result = Ok(tx).and_then(errors::check_block_gap(&*self.client, self.options));
        Box::new(future::done(result))
    }

    fn transaction_by_block_hash_and_index(
        &self,
        hash: H256,
        index: Index,
    ) -> BoxFuture<Option<Transaction>> {
        let id = PendingTransactionId::Location(
            PendingOrBlock::Block(BlockId::Hash(hash)),
            index.value(),
        );
        let result = self
            .transaction(id)
            .and_then(errors::check_block_gap(&*self.client, self.options));
        Box::new(future::done(result))
    }

    fn transaction_by_block_number_and_index(
        &self,
        num: BlockNumber,
        index: Index,
    ) -> BoxFuture<Option<Transaction>> {
        let block_id = match num {
            BlockNumber::Hash { hash, .. } => PendingOrBlock::Block(BlockId::Hash(hash)),
            BlockNumber::Latest => PendingOrBlock::Block(BlockId::Latest),
            BlockNumber::Earliest => PendingOrBlock::Block(BlockId::Earliest),
            BlockNumber::Num(num) => PendingOrBlock::Block(BlockId::Number(num)),
            BlockNumber::Pending => PendingOrBlock::Pending,
        };

        let transaction_id = PendingTransactionId::Location(block_id, index.value());
        let result =
            self.transaction(transaction_id)
                .and_then(errors::check_block_number_existence(
                    &*self.client,
                    num,
                    self.options,
                ));
        Box::new(future::done(result))
    }

    fn transaction_receipt(&self, hash: H256) -> BoxFuture<Option<Receipt>> {
        let best_block = self.client.chain_info().best_block_number;
        if let Some(receipt) = self.miner.pending_receipt(best_block, &hash) {
            return Box::new(future::ok(Some(receipt.into())));
        }

        let receipt = self.client.transaction_receipt(TransactionId::Hash(hash));
        let result = Ok(receipt.map(Into::into))
            .and_then(errors::check_block_gap(&*self.client, self.options));
        Box::new(future::done(result))
    }

    fn uncle_by_block_hash_and_index(
        &self,
        hash: H256,
        index: Index,
    ) -> BoxFuture<Option<RichBlock>> {
        let result = self
            .uncle(PendingUncleId {
                id: PendingOrBlock::Block(BlockId::Hash(hash)),
                position: index.value(),
            })
            .and_then(errors::check_block_gap(&*self.client, self.options));
        Box::new(future::done(result))
    }

    fn uncle_by_block_number_and_index(
        &self,
        num: BlockNumber,
        index: Index,
    ) -> BoxFuture<Option<RichBlock>> {
        let id = match num {
            BlockNumber::Hash { hash, .. } => PendingUncleId {
                id: PendingOrBlock::Block(BlockId::Hash(hash)),
                position: index.value(),
            },
            BlockNumber::Latest => PendingUncleId {
                id: PendingOrBlock::Block(BlockId::Latest),
                position: index.value(),
            },
            BlockNumber::Earliest => PendingUncleId {
                id: PendingOrBlock::Block(BlockId::Earliest),
                position: index.value(),
            },
            BlockNumber::Num(num) => PendingUncleId {
                id: PendingOrBlock::Block(BlockId::Number(num)),
                position: index.value(),
            },

            BlockNumber::Pending => PendingUncleId {
                id: PendingOrBlock::Pending,
                position: index.value(),
            },
        };

        let result = self
            .uncle(id)
            .and_then(errors::check_block_number_existence(
                &*self.client,
                num,
                self.options,
            ));

        Box::new(future::done(result))
    }

    fn compilers(&self) -> Result<Vec<String>> {
        Err(errors::deprecated(
            "Compilation functionality is deprecated.".to_string(),
        ))
    }

    fn logs(&self, filter: Filter) -> BoxFuture<Vec<Log>> {
        let include_pending = filter.to_block == Some(BlockNumber::Pending);
        let filter: EthcoreFilter = match filter.try_into() {
            Ok(value) => value,
            Err(err) => return Box::new(future::err(err)),
        };
        let mut logs = match self.client.logs(filter.clone()) {
            Ok(logs) => logs.into_iter().map(From::from).collect::<Vec<Log>>(),
            Err(id) => return Box::new(future::err(errors::filter_block_not_found(id))),
        };

        if include_pending {
            let best_block = self.client.chain_info().best_block_number;
            let pending = pending_logs(&*self.miner, best_block, &filter);
            logs.extend(pending);
        }

        let logs = limit_logs(logs, filter.limit);

        Box::new(future::ok(logs))
    }

    fn work(&self, no_new_work_timeout: Option<u64>) -> Result<Work> {
        let no_new_work_timeout = no_new_work_timeout.unwrap_or_default();

        // check if we're still syncing and return empty strings in that case
        {
            let sync_status = self.sync.status();
            let queue_info = self.client.queue_info();
            let total_queue_size = queue_info.total_queue_size();

            if sync_status.is_snapshot_syncing() || total_queue_size > MAX_QUEUE_SIZE_TO_MINE_ON {
                trace!(target: "miner", "Syncing. Cannot give any work.");
                return Err(errors::no_work());
            }

            // Otherwise spin until our submitted block has been included.
            let timeout = Instant::now() + Duration::from_millis(1000);
            while Instant::now() < timeout && self.client.queue_info().total_queue_size() > 0 {
                thread::sleep(Duration::from_millis(1));
            }
        }

        if self.miner.authoring_params().author.is_zero() {
            warn!(target: "miner", "Cannot give work package - no author is configured. Use --author to configure!");
            return Err(errors::no_author());
        }

        let work = self.miner.work_package(&*self.client).ok_or_else(|| {
            warn!(target: "miner", "Cannot give work package - engine seals internally.");
            errors::no_work_required()
        })?;

        let (pow_hash, number, timestamp, difficulty) = work;
        let target = ethash::difficulty_to_boundary(&difficulty);
        let seed_hash = self.seed_compute.lock().hash_block_number(number);

        let now = SystemTime::now()
            .duration_since(UNIX_EPOCH)
            .unwrap_or_default()
            .as_secs();
        if no_new_work_timeout > 0 && timestamp + no_new_work_timeout < now {
            Err(errors::no_new_work())
        } else {
            Ok(Work {
                pow_hash,
                seed_hash: seed_hash.into(),
                target,
                number: Some(number),
            })
        }
    }

    fn submit_work(&self, nonce: H64, pow_hash: H256, mix_hash: H256) -> Result<bool> {
        match helpers::submit_work_detail(&self.client, &self.miner, nonce, pow_hash, mix_hash) {
            Ok(_) => Ok(true),
            Err(_) => Ok(false),
        }
    }

    fn submit_hashrate(&self, rate: U256, id: H256) -> Result<bool> {
        self.external_miner.submit_hashrate(rate, id);
        Ok(true)
    }

    fn send_raw_transaction(&self, raw: Bytes) -> Result<H256> {
        TypedTransaction::decode(&raw.into_vec())
            .map_err(errors::rlp)
            .and_then(|tx| SignedTransaction::new(tx).map_err(errors::transaction))
            .and_then(|signed_transaction| {
                FullDispatcher::dispatch_transaction(
                    &*self.client,
                    &*self.miner,
                    signed_transaction.into(),
                    false,
                )
            })
            .map(Into::into)
    }

    fn submit_transaction(&self, raw: Bytes) -> Result<H256> {
        self.send_raw_transaction(raw)
    }

    fn call(&self, request: CallRequest, num: Option<BlockNumber>) -> BoxFuture<Bytes> {
        let request = CallRequest::into(request);
        let signed = try_bf!(fake_sign::sign_call(request));

        let num = num.unwrap_or_default();

        let (mut state, header) = if num == BlockNumber::Pending {
            self.pending_state_and_header_with_fallback()
        } else {
            let id = match num {
                BlockNumber::Hash { hash, .. } => BlockId::Hash(hash),
                BlockNumber::Num(num) => BlockId::Number(num),
                BlockNumber::Earliest => BlockId::Earliest,
                BlockNumber::Latest => BlockId::Latest,
                BlockNumber::Pending => unreachable!(), // Already covered
            };

            let state = try_bf!(self.client.state_at(id).ok_or_else(errors::state_pruned));
            let header = try_bf!(self
                .client
                .block_header(id)
                .ok_or_else(errors::state_pruned)
                .and_then(|h| h
                    .decode(self.client.engine().params().eip1559_transition)
                    .map_err(errors::decode)));

            (state, header)
        };

        let result = self
            .client
            .call(&signed, Default::default(), &mut state, &header);

        Box::new(future::done(
            result
                .map_err(errors::call)
                .and_then(|executed| match executed.exception {
                    Some(ref exception) => Err(errors::vm(exception, &executed.output)),
                    None => Ok(executed),
                })
                .map(|b| b.output.into()),
        ))
    }

    fn estimate_gas(&self, request: CallRequest, num: Option<BlockNumber>) -> BoxFuture<U256> {
        let request = CallRequest::into(request);
        let signed = try_bf!(fake_sign::sign_call(request));
        let num = num.unwrap_or_default();

        let (state, header) = if num == BlockNumber::Pending {
            self.pending_state_and_header_with_fallback()
        } else {
            let id = match num {
                BlockNumber::Hash { hash, .. } => BlockId::Hash(hash),
                BlockNumber::Num(num) => BlockId::Number(num),
                BlockNumber::Earliest => BlockId::Earliest,
                BlockNumber::Latest => BlockId::Latest,
                BlockNumber::Pending => unreachable!(), // Already covered
            };

            let state = try_bf!(self.client.state_at(id).ok_or_else(errors::state_pruned));
            let header = try_bf!(self
                .client
                .block_header(id)
                .ok_or_else(errors::state_pruned)
                .and_then(|h| h
                    .decode(self.client.engine().params().eip1559_transition)
                    .map_err(errors::decode)));
            (state, header)
        };

        Box::new(future::done(
            self.client
                .estimate_gas(&signed, &state, &header)
                .map_err(errors::call),
        ))
    }

    fn compile_lll(&self, _: String) -> Result<Bytes> {
        Err(errors::deprecated(
            "Compilation of LLL via RPC is deprecated".to_string(),
        ))
    }

    fn compile_serpent(&self, _: String) -> Result<Bytes> {
        Err(errors::deprecated(
            "Compilation of Serpent via RPC is deprecated".to_string(),
        ))
    }

    fn compile_solidity(&self, _: String) -> Result<Bytes> {
        Err(errors::deprecated(
            "Compilation of Solidity via RPC is deprecated".to_string(),
        ))
    }
}