// Copyright 2015, 2016 Ethcore (UK) Ltd.
// This file is part of Parity.

// Parity 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.

// Parity 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 Parity.  If not, see <http://www.gnu.org/licenses/>.

//! Creates and registers client and network services.

use util::*;
use io::*;
use spec::Spec;
use error::*;
use client::{Client, ClientConfig, ChainNotify};
use miner::Miner;
use snapshot::service::Service as SnapshotService;
use std::sync::atomic::AtomicBool;

#[cfg(feature="ipc")]
use nanoipc;
#[cfg(feature="ipc")]
use client::BlockChainClient;

/// Message type for external and internal events
#[derive(Clone)]
pub enum ClientIoMessage {
	/// Best Block Hash in chain has been changed
	NewChainHead,
	/// A block is ready
	BlockVerified,
	/// New transaction RLPs are ready to be imported
	NewTransactions(Vec<Bytes>),
	/// Feed a state chunk to the snapshot service
	FeedStateChunk(H256, Bytes),
	/// Feed a block chunk to the snapshot service
	FeedBlockChunk(H256, Bytes),
}

/// Client service setup. Creates and registers client and network services with the IO subsystem.
pub struct ClientService {
	io_service: Arc<IoService<ClientIoMessage>>,
	client: Arc<Client>,
	snapshot: Arc<SnapshotService>,
	panic_handler: Arc<PanicHandler>,
	_stop_guard: ::devtools::StopGuard,
}

impl ClientService {
	/// Start the service in a separate thread.
	pub fn start(
		config: ClientConfig,
		spec: &Spec,
		db_path: &Path,
		miner: Arc<Miner>,
		) -> Result<ClientService, Error>
	{
		let panic_handler = PanicHandler::new_in_arc();
		let io_service = try!(IoService::<ClientIoMessage>::start());
		panic_handler.forward_from(&io_service);

		info!("Configured for {} using {} engine", Colour::White.bold().paint(spec.name.clone()), Colour::Yellow.bold().paint(spec.engine.name()));
		if spec.fork_name.is_some() {
			warn!("Your chain is an alternative fork. {}", Colour::Red.bold().paint("TRANSACTIONS MAY BE REPLAYED ON THE MAINNET!"));
		}

		let pruning = config.pruning;
		let client = try!(Client::new(config, &spec, db_path, miner, io_service.channel()));
		let snapshot = try!(SnapshotService::new(spec, pruning, db_path.into(), io_service.channel()));

		let snapshot = Arc::new(snapshot);

		panic_handler.forward_from(&*client);
		let client_io = Arc::new(ClientIoHandler {
			client: client.clone(),
			snapshot: snapshot.clone(),
		});
		try!(io_service.register_handler(client_io));

		let stop_guard = ::devtools::StopGuard::new();
		run_ipc(client.clone(), stop_guard.share());

		Ok(ClientService {
			io_service: Arc::new(io_service),
			client: client,
			snapshot: snapshot,
			panic_handler: panic_handler,
			_stop_guard: stop_guard,
		})
	}

	/// Add a node to network
	pub fn add_node(&mut self, _enode: &str) {
		unimplemented!();
	}

	/// Get general IO interface
	pub fn register_io_handler(&self, handler: Arc<IoHandler<ClientIoMessage> + Send>) -> Result<(), IoError> {
		self.io_service.register_handler(handler)
	}

	/// Get client interface
	pub fn client(&self) -> Arc<Client> {
		self.client.clone()
	}

	/// Get snapshot interface.
	pub fn snapshot_service(&self) -> Arc<SnapshotService> {
		self.snapshot.clone()
	}

	/// Get network service component
	pub fn io(&self) -> Arc<IoService<ClientIoMessage>> {
		self.io_service.clone()
	}

	/// Set the actor to be notified on certain chain events
	pub fn add_notify(&self, notify: Arc<ChainNotify>) {
		self.client.add_notify(notify);
	}
}

impl MayPanic for ClientService {
	fn on_panic<F>(&self, closure: F) where F: OnPanicListener {
		self.panic_handler.on_panic(closure);
	}
}

/// IO interface for the Client handler
struct ClientIoHandler {
	client: Arc<Client>,
	snapshot: Arc<SnapshotService>,
}

const CLIENT_TICK_TIMER: TimerToken = 0;
const CLIENT_TICK_MS: u64 = 5000;

impl IoHandler<ClientIoMessage> for ClientIoHandler {
	fn initialize(&self, io: &IoContext<ClientIoMessage>) {
		io.register_timer(CLIENT_TICK_TIMER, CLIENT_TICK_MS).expect("Error registering client timer");
	}

	fn timeout(&self, _io: &IoContext<ClientIoMessage>, timer: TimerToken) {
		if timer == CLIENT_TICK_TIMER {
			self.client.tick();
		}
	}

	#[cfg_attr(feature="dev", allow(single_match))]
	fn message(&self, _io: &IoContext<ClientIoMessage>, net_message: &ClientIoMessage) {
		match *net_message {
			ClientIoMessage::BlockVerified => { self.client.import_verified_blocks(); }
			ClientIoMessage::NewTransactions(ref transactions) => { self.client.import_queued_transactions(transactions); }
			ClientIoMessage::FeedStateChunk(ref hash, ref chunk) => self.snapshot.feed_state_chunk(*hash, chunk),
			ClientIoMessage::FeedBlockChunk(ref hash, ref chunk) => self.snapshot.feed_block_chunk(*hash, chunk),
			_ => {} // ignore other messages
		}
	}
}

#[cfg(feature="ipc")]
fn run_ipc(client: Arc<Client>, stop: Arc<AtomicBool>) {
	::std::thread::spawn(move || {
		let mut worker = nanoipc::Worker::new(&(client as Arc<BlockChainClient>));
		worker.add_reqrep("ipc:///tmp/parity-chain.ipc").expect("Ipc expected to initialize with no issues");

		while !stop.load(::std::sync::atomic::Ordering::Relaxed) {
			worker.poll();
		}
	});
}

#[cfg(not(feature="ipc"))]
fn run_ipc(_client: Arc<Client>, _stop: Arc<AtomicBool>) {
}

#[cfg(test)]
mod tests {
	use super::*;
	use tests::helpers::*;
	use devtools::*;
	use client::ClientConfig;
	use std::sync::Arc;
	use miner::Miner;

	#[test]
	fn it_can_be_started() {
		let temp_path = RandomTempPath::new();
		let mut path = temp_path.as_path().to_owned();
		path.push("pruning");
		path.push("db");

		let spec = get_test_spec();
		let service = ClientService::start(
			ClientConfig::default(),
			&spec,
			&path,
			Arc::new(Miner::with_spec(&spec)),
		);
		assert!(service.is_ok());
		drop(service.unwrap());
		::std::thread::park_timeout(::std::time::Duration::from_millis(100));
	}
}