#![deny(unused_results)]

pub mod benchmarking;
pub mod chain_spec;

#[cfg(feature = "full-node")]
use {
    grandpa::{self, FinalityProofProvider as GrandpaFinalityProofProvider},
    sc_client_api::BlockBackend,
    tx_pool_api::OffchainTransactionPoolFactory,
    sp_blockchain::HeaderBackend,
    sc_service::{KeystoreContainer, RpcHandlers},
    telemetry::{Telemetry, TelemetryWorkerHandle},
};

use std::{sync::Arc, time::Duration};
use telemetry::TelemetryWorker;
use sc_executor::{HeapAllocStrategy, WasmExecutor, DEFAULT_HEAP_ALLOC_STRATEGY};

pub use chain_spec::GenericChainSpec;
pub use consensus_common::{Proposal, SelectChain};
pub use primitives::{Block, BlockId, BlockNumber, Hash};
pub use sc_client_api::{Backend, CallExecutor};
pub use sc_consensus::BlockImport;
pub use sc_executor::NativeExecutionDispatch;
pub use sp_api::{ApiRef, ConstructRuntimeApi, Core as CoreApi, ProvideRuntimeApi};
pub use sc_service::{
    config::{DatabaseSource, PrometheusConfig},
    ChainSpec, Configuration, Error as SubstrateServiceError, PruningMode, Role,
    RuntimeGenesis, TFullBackend, TFullCallExecutor, TFullClient, TaskManager,
    TransactionPoolOptions,
};
pub use sp_runtime::{
    generic,
    traits::{
        self as runtime_traits, BlakeTwo256, Block as BlockT, Header as HeaderT,
        NumberFor,
    },
};

#[cfg(feature = "casper-native")]
pub use chain_spec::CasperChainSpec;
#[cfg(feature = "casper-native")]
pub use {casper_runtime, casper_runtime_constants};
#[cfg(feature = "casper-native")]
use casper_runtime::RuntimeApi;

#[cfg(feature = "full-node")]
pub type FullBackend = sc_service::TFullBackend<Block>;

#[cfg(feature = "full-node")]
pub type FullClient = sc_service::TFullClient<
    Block,
    RuntimeApi,
    WasmExecutor<(
        sp_io::SubstrateHostFunctions, 
        frame_benchmarking::benchmarking::HostFunctions,
    )>,
>;

const GRANDPA_JUSTIFICATION_PERIOD: u32 = 512;

pub trait HeaderProvider<Block, Error = sp_blockchain::Error>: Send + Sync + 'static
where
    Block: BlockT,
    Error: std::fmt::Debug + Send + Sync + 'static,
{
    fn header(
        &self,
        hash: <Block as BlockT>::Hash,
    ) -> Result<Option<<Block as BlockT>::Header>, Error>;

    fn number(
        &self,
        hash: <Block as BlockT>::Hash,
    ) -> Result<Option<<<Block as BlockT>::Header as HeaderT>::Number>, Error>;
}

impl<Block, T> HeaderProvider<Block> for T
where
    Block: BlockT,
    T: sp_blockchain::HeaderBackend<Block> + 'static,
{
    fn header(
        &self,
        hash: Block::Hash,
    ) -> sp_blockchain::Result<Option<<Block as BlockT>::Header>> {
        <Self as sp_blockchain::HeaderBackend<Block>>::header(self, hash)
    }

    fn number(
        &self,
        hash: Block::Hash,
    ) -> sp_blockchain::Result<Option<<<Block as BlockT>::Header as HeaderT>::Number>> {
        <Self as sp_blockchain::HeaderBackend<Block>>::number(self, hash)
    }
}

pub trait HeaderProviderProvider<Block>: Send + Sync + 'static
where 
    Block: BlockT,
{
    type Provider: HeaderProvider<Block> + 'static;

    fn header_provider(&self) -> &Self::Provider;
}

impl<Block, T> HeaderProviderProvider<Block> for T
where
    Block: BlockT,
    T: sc_client_api::Backend<Block> + 'static,
{
    type Provider = <T as sc_client_api::Backend<Block>>::Blockchain;

    fn header_provider(&self) -> &Self::Provider {
        self.blockchain()
    }
}

#[derive(thiserror::Error, Debug)]
pub enum Error {
    #[error(transparent)]
    Io(#[from] std::io::Error),

    #[error(transparent)]
    AddrFormatInvalid(#[from] std::net::AddrParseError),

    #[error(transparent)]
    Sub(#[from] SubstrateServiceError),

    #[error(transparent)]
    Blockchain(#[from] sp_blockchain::Error),

    #[error(transparent)]
    Consensus(#[from] consensus_common::Error),

    #[error(transparent)]
    Prometheus(#[from] prometheus_endpoint::PrometheusError),

    #[error(transparent)]
    Telemetry(#[from] telemetry::Error),

    #[cfg(feature = "full-node")]
    #[error("Creating a custom database is required for validators")]
    DatabasePathRequired,

    #[cfg(feature = "full-node")]
    #[error("Expected at least one of ghost or casper runtime feature")]
    NoRuntime,
}

#[derive(Debug, Clone, Copy, PartialEq)]
pub enum Chain {
    Ghost,
    Casper,
    Unknown,
}

pub trait IdentifyVariant {
    fn is_ghost(&self) -> bool;
    fn is_casper(&self) -> bool;
    fn is_dev(&self) -> bool;
    fn identify_chain(&self) -> Chain;
}

impl IdentifyVariant for Box<dyn ChainSpec> {
    fn is_ghost(&self) -> bool {
        self.id().starts_with("ghost")
    }

    fn is_casper(&self) -> bool {
        self.id().starts_with("casper")
    }

    fn is_dev(&self) -> bool {
        self.id().ends_with("dev")
    }

    fn identify_chain(&self) -> Chain {
        if self.is_ghost() { Chain::Ghost }
        else if self.is_casper() { Chain::Casper }
        else { Chain::Unknown }
    }
}

#[cfg(feature = "full-node")]
type FullSelectChain = sc_consensus::LongestChain<FullBackend, Block>;
#[cfg(feature = "full-node")]
type FullGrandpaBlockImport<ChainSelection = FullSelectChain> =
    grandpa::GrandpaBlockImport<FullBackend, Block, FullClient, ChainSelection>;

#[cfg(feature = "full-node")]
struct Basics {
    task_manager: TaskManager,
    client: Arc<FullClient>,
    backend: Arc<FullBackend>,
    keystore_container: KeystoreContainer,
    telemetry: Option<Telemetry>,
}

#[cfg(feature = "full-node")]
fn new_partial_basics(
    config: &mut Configuration,
    telemetry_worker_handle: Option<TelemetryWorkerHandle>,
) -> Result<Basics, Error> {
    let telemetry = config
        .telemetry_endpoints
        .clone()
        .filter(|x| !x.is_empty())
        .map(move |endpoints| -> Result<_, telemetry::Error> {
            let (worker, mut worker_handle) = if let Some(worker_handle) = telemetry_worker_handle {
                (None, worker_handle)
            } else {
                let worker = TelemetryWorker::new(16)?;
                let worker_handle = worker.handle();
                (Some(worker), worker_handle)
            };
            let telemetry = worker_handle.new_telemetry(endpoints);
            Ok((worker, telemetry))
        })
        .transpose()?;

    let heap_pages = config
        .default_heap_pages
        .map_or(DEFAULT_HEAP_ALLOC_STRATEGY, |h| HeapAllocStrategy::Static { extra_pages: h as _ });

    let executor = WasmExecutor::builder()
        .with_execution_method(config.wasm_method)
        .with_onchain_heap_alloc_strategy(heap_pages)
        .with_offchain_heap_alloc_strategy(heap_pages)
        .with_max_runtime_instances(config.max_runtime_instances)
        .with_runtime_cache_size(config.runtime_cache_size)
        .build();

    let (client, backend, keystore_container, task_manager) =
        sc_service::new_full_parts::<Block, RuntimeApi, _>(
            &config,
            telemetry.as_ref().map(|(_, telemetry)| telemetry.handle()),
            executor,
        )?;
    let client = Arc::new(client);

    let telemetry = telemetry.map(|(worker, telemetry)| {
        if let Some(worker) = worker {
            task_manager.spawn_handle().spawn(
                "telemetry",
                Some("telemetry"),
                Box::pin(worker.run()),
            );
        }
        telemetry
    });

    Ok(Basics { task_manager, client, backend, keystore_container, telemetry })
}

#[cfg(feature = "full-node")]
fn new_partial<ChainSelection>(
    config: &mut Configuration,
    Basics { task_manager, backend, client, keystore_container, telemetry }: Basics,
    select_chain: ChainSelection,
) -> Result<
    sc_service::PartialComponents<
        FullClient,
        FullBackend,
        ChainSelection,
        sc_consensus::DefaultImportQueue<Block>,
        sc_transaction_pool::FullPool<Block, FullClient>,
        (
            impl Fn(
                ghost_rpc::DenyUnsafe,
                ghost_rpc::SubscriptionTaskExecutor,
            ) -> Result<ghost_rpc::RpcExtension, SubstrateServiceError>,
            (
                babe::BabeBlockImport<
                    Block,
                    FullClient, 
                    FullGrandpaBlockImport<ChainSelection>,
                >,
                grandpa::LinkHalf<Block, FullClient, ChainSelection>,
                babe::BabeLink<Block>,
            ),
            grandpa::SharedVoterState,
            Option<Telemetry>,
        ),
    >,
    Error,
>
where 
    ChainSelection: 'static + SelectChain<Block>,
{
    let transaction_pool = sc_transaction_pool::BasicPool::new_full(
        config.transaction_pool.clone(),
        config.role.is_authority().into(),
        config.prometheus_registry(),
        task_manager.spawn_essential_handle(),
        client.clone(),
    );

    let (grandpa_block_import, grandpa_link) =
        grandpa::block_import(
            client.clone(),
            GRANDPA_JUSTIFICATION_PERIOD,
            &(client.clone() as Arc<_>),
            select_chain.clone(),
            telemetry.as_ref().map(|x| x.handle()),
        )?;
    let justification_import = grandpa_block_import.clone();

    let babe_config = babe::configuration(&*client)?;
    let (block_import, babe_link) = 
        babe::block_import(babe_config.clone(), grandpa_block_import, client.clone())?;

    let slot_duration = babe_link.config().slot_duration();
    let (import_queue, babe_worker_handle) =
        babe::import_queue(babe::ImportQueueParams {
            link: babe_link.clone(),
            block_import: block_import.clone(),
            justification_import: Some(Box::new(justification_import)),
            client: client.clone(),
            select_chain: select_chain.clone(),
            create_inherent_data_providers: move |_, ()| async move {
                let timestamp = sp_timestamp::InherentDataProvider::from_system_time();
                let slot =
                    babe_primitives::inherents::InherentDataProvider::from_timestamp_and_slot_duration(
                        *timestamp,
                        slot_duration,
                    );
                Ok((slot, timestamp))
            },
            spawner: &task_manager.spawn_essential_handle(),
            registry: config.prometheus_registry(),
            telemetry: telemetry.as_ref().map(|x| x.handle()),
            offchain_tx_pool_factory: OffchainTransactionPoolFactory::new(transaction_pool.clone()),
        })?;

    let justification_stream = grandpa_link.justification_stream();
    let shared_authority_set = grandpa_link.shared_authority_set().clone();
    let shared_voter_state = grandpa::SharedVoterState::empty();
    let finality_proof_provider = GrandpaFinalityProofProvider::new_for_service(
        backend.clone(),
        Some(shared_authority_set.clone()),
    );

    let import_setup = (block_import, grandpa_link, babe_link);
    let rpc_setup = shared_voter_state.clone();

    let rpc_extensions_builder = {
        let client = client.clone();
        let keystore = keystore_container.keystore();
        let transaction_pool = transaction_pool.clone();
        let select_chain = select_chain.clone();
        let chain_spec = config.chain_spec.cloned_box();
        let backend = backend.clone();

        move |
            deny_unsafe, 
            subscription_executor: ghost_rpc::SubscriptionTaskExecutor,
        | -> Result<ghost_rpc::RpcExtension, sc_service::Error> {
            let deps = ghost_rpc::FullDeps {
                client: client.clone(),
                pool: transaction_pool.clone(),
                select_chain: select_chain.clone(),
                chain_spec: chain_spec.cloned_box(),
                deny_unsafe,
                babe: ghost_rpc::BabeDeps {
                    babe_worker_handle: babe_worker_handle.clone(),
                    keystore: keystore.clone(),
                },
                grandpa: ghost_rpc::GrandpaDeps {
                    shared_voter_state: shared_voter_state.clone(),
                    shared_authority_set: shared_authority_set.clone(),
                    justification_stream: justification_stream.clone(),
                    subscription_executor: subscription_executor.clone(),
                    finality_provider: finality_proof_provider.clone(),
                },
                backend: backend.clone(),
            };

            ghost_rpc::create_full_rpc(deps).map_err(Into::into)
        }
    };

    Ok(sc_service::PartialComponents {
        client,
        backend,
        task_manager,
        keystore_container,
        select_chain,
        import_queue,
        transaction_pool,
        other: (rpc_extensions_builder, import_setup, rpc_setup, telemetry),
    })
}

#[cfg(feature = "full-node")]
pub struct NewFullParams {
    /// Whether to enable the block authoring backoff on production networks
    /// where it isn't enabled by default.
    pub force_authoring_backoff: bool,
    pub telemetry_worker_handle: Option<TelemetryWorkerHandle>,
    pub hwbench: Option<sc_sysinfo::HwBench>,
}

#[cfg(feature = "full-node")]
pub struct NewFull {
    pub task_manager: TaskManager,
    pub client: Arc<FullClient>,
    pub network: Arc<dyn sc_network::service::traits::NetworkService>,
    pub sync_service: Arc<sc_network_sync::SyncingService<Block>>,
    pub rpc_handlers: RpcHandlers,
    pub backend: Arc<FullBackend>,
}

#[cfg(feature = "full-node")]
pub fn new_full<Network: sc_network::NetworkBackend<Block, <Block as BlockT>::Hash>>(
    mut config: Configuration,
    NewFullParams {
        force_authoring_backoff,
        telemetry_worker_handle,
        hwbench,
    }: NewFullParams,
) -> Result<NewFull, Error> {
    use sc_network_sync::WarpSyncParams;

    let role = config.role.clone();
    let force_authoring = config.force_authoring;
    let backoff_authoring_blocks = if !force_authoring_backoff { 
        None
    } else {
        let mut backoff =
            sc_consensus_slots::BackoffAuthoringOnFinalizedHeadLagging::default();

        if config.chain_spec.is_dev() {
            backoff.max_interval = 10;
        }

        Some(backoff)
    };

    let disable_grandpa = config.disable_grandpa;
    let name = config.network.node_name.clone();

    let basics = new_partial_basics(&mut config, telemetry_worker_handle)?;

    let prometheus_registry = config.prometheus_registry().cloned();
    let select_chain = sc_consensus::LongestChain::new(basics.backend.clone());

    let sc_service::PartialComponents::<_, _, sc_consensus::LongestChain<FullBackend, Block>, _, _, _,> {
        client,
        backend,
        mut task_manager,
        keystore_container,
        select_chain,
        import_queue,
        transaction_pool,
        other: (
            rpc_extensions_builder, 
            import_setup, 
            rpc_setup, 
            mut telemetry,
        ),
    } = new_partial::<sc_consensus::LongestChain<FullBackend, Block>>(
        &mut config, 
        basics, 
        select_chain,
    )?;

    let metrics = Network::register_notification_metrics(
        config.prometheus_config.as_ref().map(|cfg| &cfg.registry),
    );
    let shared_voter_state = rpc_setup;
    let auth_disc_publish_non_global_ips = config.network.allow_non_globals_in_dht;
    let auth_disc_public_addresses = config.network.public_addresses.clone();

    let mut net_config = 
        sc_network::config::FullNetworkConfiguration::<_, _, Network>::new(&config.network);

    let genesis_hash = client.block_hash(0).ok().flatten().expect("Genesis block exists; qed");
    let peer_store_handle = net_config.peer_store_handle();

    let grandpa_protocol_name = grandpa::protocol_standard_name(&genesis_hash, &config.chain_spec);
    let (grandpa_protocol_config, grandpa_notification_service) =
        grandpa::grandpa_peers_set_config::<_, Network>(
            grandpa_protocol_name.clone(),
            metrics.clone(),
            Arc::clone(&peer_store_handle),
        );
    net_config.add_notification_protocol(grandpa_protocol_config);

    let warp_sync = Arc::new(grandpa::warp_proof::NetworkProvider::new(
        backend.clone(),
        import_setup.1.shared_authority_set().clone(),
        Vec::new(),
    ));

    let (network, system_rpc_tx, tx_handler_controller, network_starter, sync_service) =
        sc_service::build_network(sc_service::BuildNetworkParams {
            config: &config,
            net_config,
            client: client.clone(),
            transaction_pool: transaction_pool.clone(),
            spawn_handle: task_manager.spawn_handle(),
            import_queue,
            block_announce_validator_builder: None,
            warp_sync_params: Some(WarpSyncParams::WithProvider(warp_sync)),
            block_relay: None,
            metrics,
        })?;

    if config.offchain_worker.enabled {
        use futures::FutureExt;

        task_manager.spawn_handle().spawn(
            "offchain-workers-runner",
            "offchain-worker",
            sc_offchain::OffchainWorkers::new(sc_offchain::OffchainWorkerOptions {
                runtime_api_provider: client.clone(),
                keystore: Some(keystore_container.keystore()),
                offchain_db: backend.offchain_storage(),
                transaction_pool: Some(OffchainTransactionPoolFactory::new(
                    transaction_pool.clone(),
                )),
                network_provider: Arc::new(network.clone()),
                is_validator: role.is_authority(),
                enable_http_requests: true,
                custom_extensions: move |_| vec![],
            })
            .run(client.clone(), task_manager.spawn_handle())
            .boxed(),
        );
    }

    let rpc_handlers = sc_service::spawn_tasks(sc_service::SpawnTasksParams {
        config,
        backend: backend.clone(),
        client: client.clone(),
        keystore: keystore_container.keystore(),
        network: network.clone(),
        sync_service: sync_service.clone(),
        rpc_builder: Box::new(rpc_extensions_builder),
        transaction_pool: transaction_pool.clone(),
        task_manager: &mut task_manager,
        system_rpc_tx,
        tx_handler_controller,
        telemetry: telemetry.as_mut(),
    })?;

    if let Some(hwbench) = hwbench {
        sc_sysinfo::print_hwbench(&hwbench);
        match ghost_machine_primitives::GHOST_NODE_REFERENCE_HARDWARE.check_hardware(&hwbench) {
            Err(err) if role.is_authority() => {
                log::warn!(
                    "⚠️  The hardware does not meet the minimal requirements {} for role 'Authority'",
                    err
                );
            },
            _ => {},
        }

        if let Some(ref mut telemetry) = telemetry {
            let telemetry_handle = telemetry.handle();
            task_manager.spawn_handle().spawn(
                "telemetry_hwbench",
                None,
                sc_sysinfo::initialize_hwbench_telemetry(
                    telemetry_handle, 
                    hwbench,
                ),
            );
        }
    }

    let (block_import, link_half, babe_link) = import_setup;

    if role.is_authority() {
        use futures::StreamExt;
        use sc_network::{Event, NetworkEventStream};

        let authority_discovery_role = 
            sc_authority_discovery::Role::PublishAndDiscover(keystore_container.keystore());
        let dht_event_stream = 
            network.event_stream("authority-discovery").filter_map(|e| async move {
                match e {
                    Event::Dht(e) => Some(e),
                    _ => None,
                }
            });
        let (worker, _service) = sc_authority_discovery::new_worker_and_service_with_config(
            sc_authority_discovery::WorkerConfig {
                publish_non_global_ips: auth_disc_publish_non_global_ips,
                public_addresses: auth_disc_public_addresses,
                strict_record_validation: true,
                ..Default::default()
            },
            client.clone(),
            Arc::new(network.clone()),
            Box::pin(dht_event_stream),
            authority_discovery_role,
            prometheus_registry.clone()
        );

        task_manager.spawn_handle().spawn(
            "authority-discovery-worker",
            Some("authority-discovery"),
            Box::pin(worker.run()),
        );
    }

    if role.is_authority() {
        let proposer = sc_basic_authorship::ProposerFactory::new(
            task_manager.spawn_handle(),
            client.clone(),
            transaction_pool.clone(),
            prometheus_registry.as_ref(),
            telemetry.as_ref().map(|x| x.handle()),
        );

        let slot_duration = babe_link.config().slot_duration();
        let babe_config = babe::BabeParams {
            keystore: keystore_container.keystore(),
            client: client.clone(),
            select_chain,
            block_import,
            env: proposer,
            sync_oracle: sync_service.clone(),
            justification_sync_link: sync_service.clone(),
            create_inherent_data_providers: move |_, ()| {
                async move {
                    let timestamp = sp_timestamp::InherentDataProvider::from_system_time();
                    let slot =
                        babe_primitives::inherents::InherentDataProvider::from_timestamp_and_slot_duration(
                            *timestamp,
                            slot_duration,
                        );
                    Ok((slot, timestamp))
                }
            },
            force_authoring,
            backoff_authoring_blocks,
            babe_link,
            block_proposal_slot_portion: babe::SlotProportion::new(2f32 / 3f32),
            max_block_proposal_slot_portion: None,
            telemetry: telemetry.as_ref().map(|x| x.handle()),
        }; 

        let babe = babe::start_babe(babe_config)?;

        task_manager.spawn_essential_handle().spawn_blocking("babe", None, babe);
    }

    let keystore_opt = if role.is_authority() { 
        Some(keystore_container.keystore())
    } else {
        None
    };

    let config = grandpa::Config {
        gossip_duration: Duration::from_millis(1000),
        justification_generation_period: GRANDPA_JUSTIFICATION_PERIOD,
        name: Some(name),
        observer_enabled: false,
        keystore: keystore_opt,
        local_role: role,
        telemetry: telemetry.as_ref().map(|x| x.handle()),
        protocol_name: grandpa_protocol_name,
    };

    let enable_grandpa = !disable_grandpa;
    if enable_grandpa {
        let voting_rules_builder = grandpa::VotingRulesBuilder::default();

        let granpda_config = grandpa::GrandpaParams {
            config,
            link: link_half,
            network: network.clone(),
            sync: sync_service.clone(),
            voting_rule: voting_rules_builder.build(),
            prometheus_registry: prometheus_registry.clone(),
            shared_voter_state,
            telemetry: telemetry.as_ref().map(|x| x.handle()),
            notification_service: grandpa_notification_service,
            offchain_tx_pool_factory: OffchainTransactionPoolFactory::new(transaction_pool.clone()),
        };

        task_manager.spawn_essential_handle().spawn_blocking(
            "granpda-voter",
            None,
            grandpa::run_grandpa_voter(granpda_config)?,
        );
    }

    network_starter.start_network();

    Ok(NewFull {
        task_manager,
        client,
        network,
        sync_service,
        rpc_handlers,
        backend,
    })
}

#[cfg(feature = "full-node")]
macro_rules! chain_ops {
    ($config:expr, $telemetry_worker_handle:expr) => {{
        let telemetry_worker_handle = $telemetry_worker_handle;
        let mut config = $config;
        let basics = new_partial_basics(config, telemetry_worker_handle)?;

        let chain_selection = sc_consensus::LongestChain::new(basics.backend.clone());

        let sc_service::PartialComponents { client, backend, import_queue, task_manager, .. } =
            new_partial::<sc_consensus::LongestChain<FullBackend, Block>>(&mut config, basics, chain_selection)?;
        Ok((client, backend, import_queue, task_manager))
    }};
}

#[cfg(feature = "full-node")]
pub fn new_chain_ops(
    config: &mut Configuration,
) -> Result<(Arc<FullClient>, Arc<FullBackend>, sc_consensus::BasicQueue<Block>, TaskManager), Error>
{
    config.keystore = sc_service::config::KeystoreConfig::InMemory;
    chain_ops!(config, None)
}

#[cfg(feature = "full-node")]
pub fn build_full(
    config: Configuration,
    params: NewFullParams,
) -> Result<NewFull, Error> {
    match config.network.network_backend {
        sc_network::config::NetworkBackendType::Libp2p => 
            new_full::<sc_network::NetworkWorker<Block, Hash>>(config, params),
        sc_network::config::NetworkBackendType::Litep2p => 
            new_full::<sc_network::Litep2pNetworkBackend>(config, params),
    }
}

#[cfg(feature = "full-node")]
pub fn revert_backend(
    client: Arc<FullClient>,
    backend: Arc<FullBackend>,
    blocks: BlockNumber,
) -> Result<(), Error> {
    let best_number = client.info().best_number;
    let finalized = client.info().finalized_number;
    let revertible = blocks.min(best_number - finalized);

    if revertible == 0 {
        return Ok(())
    }

    babe::revert(client.clone(), backend, blocks)?;
    grandpa::revert(client, blocks)?;

    Ok(())
}