//! Service and ServiceFactory implementation. Specialized wrapper over substrate service.

// std
use std::{sync::Arc, time::Duration};

use cumulus_client_cli::CollatorOptions;
// Local Runtime Types
use parachain_template_runtime::{opaque::Block, Hash, RuntimeApi};

// Cumulus Imports
use cumulus_client_consensus_aura::{AuraConsensus, BuildAuraConsensusParams, SlotProportion};
use cumulus_client_consensus_common::{
	ParachainBlockImport as TParachainBlockImport, ParachainConsensus,
};
use cumulus_client_network::BlockAnnounceValidator;
use cumulus_client_service::{
	build_relay_chain_interface, prepare_node_config, start_collator, start_full_node,
	StartCollatorParams, StartFullNodeParams,
};
use cumulus_primitives_core::ParaId;
use cumulus_relay_chain_interface::{RelayChainError, RelayChainInterface};

// Substrate Imports
use frame_benchmarking_cli::SUBSTRATE_REFERENCE_HARDWARE;
use sc_consensus::ImportQueue;
use sc_executor::NativeElseWasmExecutor;
use sc_network::NetworkService;
use sc_network_common::service::NetworkBlock;
use sc_service::{Configuration, PartialComponents, TFullBackend, TFullClient, TaskManager};
use sc_telemetry::{Telemetry, TelemetryHandle, TelemetryWorker, TelemetryWorkerHandle};
use sp_keystore::SyncCryptoStorePtr;
use substrate_prometheus_endpoint::Registry;

/// Native executor type.
pub struct ParachainNativeExecutor;

impl sc_executor::NativeExecutionDispatch for ParachainNativeExecutor {
	type ExtendHostFunctions = frame_benchmarking::benchmarking::HostFunctions;

	fn dispatch(method: &str, data: &[u8]) -> Option<Vec<u8>> {
		parachain_template_runtime::api::dispatch(method, data)
	}

	fn native_version() -> sc_executor::NativeVersion {
		parachain_template_runtime::native_version()
	}
}

type ParachainExecutor = NativeElseWasmExecutor<ParachainNativeExecutor>;

type ParachainClient = TFullClient<Block, RuntimeApi, ParachainExecutor>;

type ParachainBackend = TFullBackend<Block>;

type ParachainBlockImport = TParachainBlockImport<Block, Arc<ParachainClient>, ParachainBackend>;

/// Starts a `ServiceBuilder` for a full service.
///
/// Use this macro if you don't actually need the full service, but just the builder in order to
/// be able to perform chain operations.
pub fn new_partial(
	config: &Configuration,
) -> Result<
	PartialComponents<
		ParachainClient,
		ParachainBackend,
		(),
		sc_consensus::DefaultImportQueue<Block, ParachainClient>,
		sc_transaction_pool::FullPool<Block, ParachainClient>,
		(ParachainBlockImport, Option<Telemetry>, Option<TelemetryWorkerHandle>),
	>,
	sc_service::Error,
> {
	let telemetry = config
		.telemetry_endpoints
		.clone()
		.filter(|x| !x.is_empty())
		.map(|endpoints| -> Result<_, sc_telemetry::Error> {
			let worker = TelemetryWorker::new(16)?;
			let telemetry = worker.handle().new_telemetry(endpoints);
			Ok((worker, telemetry))
		})
		.transpose()?;

	let executor = ParachainExecutor::new(
		config.wasm_method,
		config.default_heap_pages,
		config.max_runtime_instances,
		config.runtime_cache_size,
	);

	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_worker_handle = telemetry.as_ref().map(|(worker, _)| worker.handle());

	let telemetry = telemetry.map(|(worker, telemetry)| {
		task_manager.spawn_handle().spawn("telemetry", None, worker.run());
		telemetry
	});

	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 block_import = ParachainBlockImport::new(client.clone(), backend.clone());

	let import_queue = build_import_queue(
		client.clone(),
		block_import.clone(),
		config,
		telemetry.as_ref().map(|telemetry| telemetry.handle()),
		&task_manager,
	)?;

	Ok(PartialComponents {
		backend,
		client,
		import_queue,
		keystore_container,
		task_manager,
		transaction_pool,
		select_chain: (),
		other: (block_import, telemetry, telemetry_worker_handle),
	})
}

/// Start a node with the given parachain `Configuration` and relay chain `Configuration`.
///
/// This is the actual implementation that is abstract over the executor and the runtime api.
#[sc_tracing::logging::prefix_logs_with("Parachain")]
async fn start_node_impl(
	parachain_config: Configuration,
	polkadot_config: Configuration,
	collator_options: CollatorOptions,
	para_id: ParaId,
	hwbench: Option<sc_sysinfo::HwBench>,
) -> sc_service::error::Result<(TaskManager, Arc<ParachainClient>)> {
	let parachain_config = prepare_node_config(parachain_config);

	let params = new_partial(&parachain_config)?;
	let (block_import, mut telemetry, telemetry_worker_handle) = params.other;

	let client = params.client.clone();
	let backend = params.backend.clone();
	let mut task_manager = params.task_manager;

	let (relay_chain_interface, collator_key) = build_relay_chain_interface(
		polkadot_config,
		&parachain_config,
		telemetry_worker_handle,
		&mut task_manager,
		collator_options.clone(),
		hwbench.clone(),
	)
	.await
	.map_err(|e| match e {
		RelayChainError::ServiceError(polkadot_service::Error::Sub(x)) => x,
		s => s.to_string().into(),
	})?;

	let block_announce_validator =
		BlockAnnounceValidator::new(relay_chain_interface.clone(), para_id);

	let force_authoring = parachain_config.force_authoring;
	let validator = parachain_config.role.is_authority();
	let prometheus_registry = parachain_config.prometheus_registry().cloned();
	let transaction_pool = params.transaction_pool.clone();
	let import_queue_service = params.import_queue.service();

	let (network, system_rpc_tx, tx_handler_controller, start_network) =
		sc_service::build_network(sc_service::BuildNetworkParams {
			config: &parachain_config,
			client: client.clone(),
			transaction_pool: transaction_pool.clone(),
			spawn_handle: task_manager.spawn_handle(),
			import_queue: params.import_queue,
			block_announce_validator_builder: Some(Box::new(|_| {
				Box::new(block_announce_validator)
			})),
			warp_sync: None,
		})?;

	if parachain_config.offchain_worker.enabled {
		sc_service::build_offchain_workers(
			&parachain_config,
			task_manager.spawn_handle(),
			client.clone(),
			network.clone(),
		);
	}

	let rpc_builder = {
		let client = client.clone();
		let transaction_pool = transaction_pool.clone();

		Box::new(move |deny_unsafe, _| {
			let deps = crate::rpc::FullDeps {
				client: client.clone(),
				pool: transaction_pool.clone(),
				deny_unsafe,
			};

			crate::rpc::create_full(deps).map_err(Into::into)
		})
	};

	sc_service::spawn_tasks(sc_service::SpawnTasksParams {
		rpc_builder,
		client: client.clone(),
		transaction_pool: transaction_pool.clone(),
		task_manager: &mut task_manager,
		config: parachain_config,
		keystore: params.keystore_container.sync_keystore(),
		backend,
		network: network.clone(),
		system_rpc_tx,
		tx_handler_controller,
		telemetry: telemetry.as_mut(),
	})?;

	if let Some(hwbench) = hwbench {
		sc_sysinfo::print_hwbench(&hwbench);
		// Here you can check whether the hardware meets your chains' requirements. Putting a link
		// in there and swapping out the requirements for your own are probably a good idea. The
		// requirements for a para-chain are dictated by its relay-chain.
		if !SUBSTRATE_REFERENCE_HARDWARE.check_hardware(&hwbench) && validator {
			log::warn!(
				"⚠️  The hardware does not meet the minimal requirements for role 'Authority'."
			);
		}

		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 announce_block = {
		let network = network.clone();
		Arc::new(move |hash, data| network.announce_block(hash, data))
	};

	let relay_chain_slot_duration = Duration::from_secs(6);

	let overseer_handle = relay_chain_interface
		.overseer_handle()
		.map_err(|e| sc_service::Error::Application(Box::new(e)))?;

	if validator {
		let parachain_consensus = build_consensus(
			client.clone(),
			block_import,
			prometheus_registry.as_ref(),
			telemetry.as_ref().map(|t| t.handle()),
			&task_manager,
			relay_chain_interface.clone(),
			transaction_pool,
			network,
			params.keystore_container.sync_keystore(),
			force_authoring,
			para_id,
		)?;

		let spawner = task_manager.spawn_handle();
		let params = StartCollatorParams {
			para_id,
			block_status: client.clone(),
			announce_block,
			client: client.clone(),
			task_manager: &mut task_manager,
			relay_chain_interface,
			spawner,
			parachain_consensus,
			import_queue: import_queue_service,
			collator_key: collator_key.expect("Command line arguments do not allow this. qed"),
			relay_chain_slot_duration,
			recovery_handle: Box::new(overseer_handle),
		};

		start_collator(params).await?;
	} else {
		let params = StartFullNodeParams {
			client: client.clone(),
			announce_block,
			task_manager: &mut task_manager,
			para_id,
			relay_chain_interface,
			relay_chain_slot_duration,
			import_queue: import_queue_service,
			recovery_handle: Box::new(overseer_handle),
		};

		start_full_node(params)?;
	}

	start_network.start_network();

	Ok((task_manager, client))
}

/// Build the import queue for the parachain runtime.
fn build_import_queue(
	client: Arc<ParachainClient>,
	block_import: ParachainBlockImport,
	config: &Configuration,
	telemetry: Option<TelemetryHandle>,
	task_manager: &TaskManager,
) -> Result<sc_consensus::DefaultImportQueue<Block, ParachainClient>, sc_service::Error> {
	let slot_duration = cumulus_client_consensus_aura::slot_duration(&*client)?;

	cumulus_client_consensus_aura::import_queue::<
		sp_consensus_aura::sr25519::AuthorityPair,
		_,
		_,
		_,
		_,
		_,
	>(cumulus_client_consensus_aura::ImportQueueParams {
		block_import,
		client,
		create_inherent_data_providers: move |_, _| async move {
			let timestamp = sp_timestamp::InherentDataProvider::from_system_time();

			let slot =
				sp_consensus_aura::inherents::InherentDataProvider::from_timestamp_and_slot_duration(
					*timestamp,
					slot_duration,
				);

			Ok((slot, timestamp))
		},
		registry: config.prometheus_registry(),
		spawner: &task_manager.spawn_essential_handle(),
		telemetry,
	})
	.map_err(Into::into)
}

fn build_consensus(
	client: Arc<ParachainClient>,
	block_import: ParachainBlockImport,
	prometheus_registry: Option<&Registry>,
	telemetry: Option<TelemetryHandle>,
	task_manager: &TaskManager,
	relay_chain_interface: Arc<dyn RelayChainInterface>,
	transaction_pool: Arc<sc_transaction_pool::FullPool<Block, ParachainClient>>,
	sync_oracle: Arc<NetworkService<Block, Hash>>,
	keystore: SyncCryptoStorePtr,
	force_authoring: bool,
	para_id: ParaId,
) -> Result<Box<dyn ParachainConsensus<Block>>, sc_service::Error> {
	let slot_duration = cumulus_client_consensus_aura::slot_duration(&*client)?;

	let proposer_factory = sc_basic_authorship::ProposerFactory::with_proof_recording(
		task_manager.spawn_handle(),
		client.clone(),
		transaction_pool,
		prometheus_registry,
		telemetry.clone(),
	);

	let params = BuildAuraConsensusParams {
		proposer_factory,
		create_inherent_data_providers: move |_, (relay_parent, validation_data)| {
			let relay_chain_interface = relay_chain_interface.clone();
			async move {
				let parachain_inherent =
					cumulus_primitives_parachain_inherent::ParachainInherentData::create_at(
						relay_parent,
						&relay_chain_interface,
						&validation_data,
						para_id,
					)
					.await;
				let timestamp = sp_timestamp::InherentDataProvider::from_system_time();

				let slot =
						sp_consensus_aura::inherents::InherentDataProvider::from_timestamp_and_slot_duration(
							*timestamp,
							slot_duration,
						);

				let parachain_inherent = parachain_inherent.ok_or_else(|| {
					Box::<dyn std::error::Error + Send + Sync>::from(
						"Failed to create parachain inherent",
					)
				})?;
				Ok((slot, timestamp, parachain_inherent))
			}
		},
		block_import,
		para_client: client,
		backoff_authoring_blocks: Option::<()>::None,
		sync_oracle,
		keystore,
		force_authoring,
		slot_duration,
		// We got around 500ms for proposing
		block_proposal_slot_portion: SlotProportion::new(1f32 / 24f32),
		// And a maximum of 750ms if slots are skipped
		max_block_proposal_slot_portion: Some(SlotProportion::new(1f32 / 16f32)),
		telemetry,
	};

	Ok(AuraConsensus::build::<sp_consensus_aura::sr25519::AuthorityPair, _, _, _, _, _, _>(params))
}

/// Start a parachain node.
pub async fn start_parachain_node(
	parachain_config: Configuration,
	polkadot_config: Configuration,
	collator_options: CollatorOptions,
	para_id: ParaId,
	hwbench: Option<sc_sysinfo::HwBench>,
) -> sc_service::error::Result<(TaskManager, Arc<ParachainClient>)> {
	start_node_impl(parachain_config, polkadot_config, collator_options, para_id, hwbench).await
}