// Copyright 2017-2018 Parity Technologies (UK) Ltd.
// This file is part of Substrate.

// Substrate 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.

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

use parking_lot::Mutex;
use network_libp2p::{Service, Severity, NodeIndex, PeerId, ProtocolId};
use std::sync::Arc;

/// IO interface for the syncing handler.
/// Provides peer connection management and an interface to the blockchain client.
pub trait SyncIo {
	/// Report a peer for misbehaviour.
	fn report_peer(&mut self, who: NodeIndex, reason: Severity);
	/// Send a packet to a peer.
	fn send(&mut self, who: NodeIndex, data: Vec<u8>);
	/// Returns peer identifier string
	fn peer_debug_info(&self, who: NodeIndex) -> String {
		who.to_string()
	}
	/// Returns information on p2p session
	fn peer_id(&self, who: NodeIndex) -> Option<PeerId>;
}

/// Wraps the network service.
pub struct NetSyncIo<'s> {
	network: &'s Arc<Mutex<Service>>,
	protocol: ProtocolId,
}

impl<'s> NetSyncIo<'s> {
	/// Creates a new instance.
	pub fn new(network: &'s Arc<Mutex<Service>>, protocol: ProtocolId) -> NetSyncIo<'s> {
		NetSyncIo {
			network,
			protocol,
		}
	}
}

impl<'s> SyncIo for NetSyncIo<'s> {
	fn report_peer(&mut self, who: NodeIndex, reason: Severity) {
		info!("Purposefully dropping {} ; reason: {:?}", who, reason);
		match reason {
			Severity::Bad(_) => self.network.lock().ban_node(who),
			Severity::Useless(_) => self.network.lock().drop_node(who),
			Severity::Timeout => self.network.lock().drop_node(who),
		}
	}

	fn send(&mut self, who: NodeIndex, data: Vec<u8>) {
		self.network.lock().send_custom_message(who, self.protocol, data)
	}

	fn peer_id(&self, who: NodeIndex) -> Option<PeerId> {
		let net = self.network.lock();
		net.peer_id_of_node(who).cloned()
	}

	fn peer_debug_info(&self, who: NodeIndex) -> String {
		let net = self.network.lock();
		if let (Some(peer_id), Some(addr)) = (net.peer_id_of_node(who), net.node_endpoint(who)) {
			format!("{:?} through {:?}", peer_id, addr)
		} else {
			"unknown".to_string()
		}
	}
}