use std::io::Write;
use std::net;
use std::sync::Arc;
use std::time::Duration;

use async_trait::async_trait;
use bytes::Bytes;
use futures::{stream, StreamExt};
use log::*;
use serde::{Deserialize, Serialize};
use structopt::StructOpt;

use tokio::sync::watch;

use tokio_unix_tcp::NamedSocketAddr;

use sodiumoxide::crypto::auth;
use sodiumoxide::crypto::sign::{ed25519, PublicKey};

use netapp::endpoint::*;
use netapp::message::*;
use netapp::peering::fullmesh::*;
use netapp::util::*;
use netapp::{NetApp, NodeID};

#[derive(StructOpt, Debug)]
#[structopt(name = "netapp")]
pub struct Opt {
	#[structopt(long = "network-key", short = "n")]
	network_key: Option<String>,

	#[structopt(long = "private-key", short = "p")]
	private_key: Option<String>,

	#[structopt(long = "bootstrap-peer", short = "b")]
	bootstrap_peers: Vec<String>,

	#[structopt(long = "listen-addr", short = "l", default_value = "127.0.0.1:1980")]
	listen_addr: String,

	#[structopt(long = "public-addr", short = "a")]
	public_addr: Option<String>,
}

#[tokio::main]
async fn main() {
	env_logger::Builder::new()
		.parse_env("RUST_LOG")
		.format(|buf, record| {
			writeln!(
				buf,
				"{} {}	{} {}",
				chrono::Local::now().format("%s%.6f"),
				record.module_path().unwrap_or("_"),
				record.level(),
				record.args()
			)
		})
		.init();

	let opt = Opt::from_args();

	let netid = match &opt.network_key {
		Some(k) => auth::Key::from_slice(&hex::decode(k).unwrap()).unwrap(),
		None => auth::gen_key(),
	};
	info!("Network key: {}", hex::encode(&netid));

	let privkey = match &opt.private_key {
		Some(k) => ed25519::SecretKey::from_slice(&hex::decode(k).unwrap()).unwrap(),
		None => {
			let (_pk, sk) = ed25519::gen_keypair();
			sk
		}
	};

	info!("Node private key: {}", hex::encode(&privkey));
	info!("Node public key: {}", hex::encode(privkey.public_key()));

	let public_addr = opt.public_addr.map(|x| x.parse().unwrap());
	let listen_addr: net::SocketAddr = opt.listen_addr.parse().unwrap();
	info!("Node public address: {:?}", public_addr);
	info!("Node listen address: {}", listen_addr);

	let netapp = NetApp::new(0u64, netid.clone(), privkey.clone());

	let mut bootstrap_peers: Vec<(PublicKey, NamedSocketAddr)> = vec![];
	for peer in opt.bootstrap_peers.iter() {
		bootstrap_peers.push(
			parse_peer_addr(peer)
				.map(|(node_id, socket_bind_addr)| (node_id, socket_bind_addr.into()))
				.expect("Invalid peer address"),
		);
	}

	let peering = FullMeshPeeringStrategy::new(
		netapp.clone(),
		bootstrap_peers,
		public_addr.map(|a| net::SocketAddr::new(a, listen_addr.port()).into()),
	);

	info!("Add more peers to this mesh by running: fullmesh -n {} -l 127.0.0.1:$((1000 + $RANDOM)) -b {}@{}",
		hex::encode(&netid),
		hex::encode(privkey.public_key()),
		listen_addr);

	let watch_cancel = netapp::util::watch_ctrl_c();

	let example = Arc::new(Example {
		netapp: netapp.clone(),
		fullmesh: peering.clone(),
		example_endpoint: netapp.endpoint("__netapp/examples/fullmesh.rs/Example".into()),
	});
	example.example_endpoint.set_handler(example.clone());

	tokio::join!(
		example.exchange_loop(watch_cancel.clone()),
		netapp.listen(listen_addr.into(), public_addr, watch_cancel.clone()),
		peering.run(watch_cancel),
	);
}

// ----

struct Example {
	netapp: Arc<NetApp>,
	fullmesh: Arc<FullMeshPeeringStrategy>,
	example_endpoint: Arc<Endpoint<ExampleMessage, Self>>,
}

impl Example {
	async fn exchange_loop(self: Arc<Self>, must_exit: watch::Receiver<bool>) {
		let mut i = 12000;
		while !*must_exit.borrow() {
			tokio::time::sleep(Duration::from_secs(2)).await;

			let peers = self.fullmesh.get_peer_list();
			for p in peers.iter() {
				let id = p.id;
				if id == self.netapp.id {
					continue;
				}
				i += 1;
				let example_field = i;
				let self2 = self.clone();
				tokio::spawn(async move {
					info!(
						"Send example query {} to {}",
						example_field,
						hex::encode(id)
					);
					// Fake data stream with some delays in item production
					let stream =
						Box::pin(stream::iter([100, 200, 300, 400]).then(|x| async move {
							tokio::time::sleep(Duration::from_millis(500)).await;
							Ok(Bytes::from(vec![(x % 256) as u8; 133 * x]))
						}));
					match self2
						.example_endpoint
						.call_streaming(
							&id,
							Req::new(ExampleMessage { example_field })
								.unwrap()
								.with_stream(stream),
							PRIO_NORMAL,
						)
						.await
					{
						Ok(resp) => {
							let (resp, stream) = resp.into_parts();
							info!(
								"Got example response to {} from {}: {:?}",
								example_field,
								hex::encode(id),
								resp
							);
							let mut stream = stream.unwrap();
							while let Some(x) = stream.next().await {
								info!("Response: stream got bytes {:?}", x.map(|b| b.len()));
							}
						}
						Err(e) => warn!("Error with example request: {}", e),
					}
				});
			}
		}
	}
}

#[async_trait]
impl StreamingEndpointHandler<ExampleMessage> for Example {
	async fn handle(
		self: &Arc<Self>,
		mut msg: Req<ExampleMessage>,
		_from: NodeID,
	) -> Resp<ExampleMessage> {
		info!(
			"Got example message: {:?}, sending example response",
			msg.msg()
		);
		let source_stream = msg.take_stream().unwrap();
		// Return same stream with 300ms delay
		let new_stream = Box::pin(source_stream.then(|x| async move {
			tokio::time::sleep(Duration::from_millis(300)).await;
			x
		}));
		Resp::new(ExampleResponse {
			example_field: false,
		})
		.with_stream(new_stream)
	}
}

#[derive(Serialize, Deserialize, Debug)]
struct ExampleMessage {
	example_field: usize,
}

#[derive(Serialize, Deserialize, Debug)]
struct ExampleResponse {
	example_field: bool,
}

impl Message for ExampleMessage {
	type Response = ExampleResponse;
}