use crate::WSClient;
use std::collections::HashMap;
use std::sync::{Arc, Mutex};
use super::{
utils::CHANNEL_PAIR_DELIMITER,
ws_client_internal::{MiscMessage, WSClientInternal},
Candlestick, OrderBook, OrderBookSnapshot, Ticker, Trade, BBO,
};
use log::*;
use serde_json::Value;
use tungstenite::Message;
pub(super) const EXCHANGE_NAME: &str = "kraken";
const WEBSOCKET_URL: &str = "wss://ws.kraken.com";
pub struct KrakenWSClient<'a> {
client: WSClientInternal<'a>,
}
fn name_pairs_to_command(name: &str, pairs: &[String], subscribe: bool) -> String {
format!(
r#"{{"event":"{}","pair":{},"subscription":{{"name":"{}"}}}}"#,
if subscribe {
"subscribe"
} else {
"unsubscribe"
},
serde_json::to_string(pairs).unwrap(),
name
)
}
fn channels_to_commands(channels: &[String], subscribe: bool) -> Vec<String> {
let mut all_commands: Vec<String> = channels
.iter()
.filter(|ch| ch.starts_with('{'))
.map(|s| s.to_string())
.collect();
let mut name_pairs = HashMap::<String, Vec<String>>::new();
for s in channels.iter().filter(|ch| !ch.starts_with('{')) {
let v: Vec<&str> = s.split(CHANNEL_PAIR_DELIMITER).collect();
let name = v[0];
let pair = v[1];
match name_pairs.get_mut(name) {
Some(pairs) => pairs.push(pair.to_string()),
None => {
name_pairs.insert(name.to_string(), vec![pair.to_string()]);
}
}
}
for (name, pairs) in name_pairs.iter() {
all_commands.push(name_pairs_to_command(name, pairs, subscribe));
}
all_commands
}
fn on_misc_msg(msg: &str) -> MiscMessage {
let resp = serde_json::from_str::<Value>(&msg);
if resp.is_err() {
error!("{} is not a JSON string, {}", msg, EXCHANGE_NAME);
return MiscMessage::Misc;
}
let value = resp.unwrap();
if value.is_object() {
let obj = value.as_object().unwrap();
let event = obj.get("event").unwrap().as_str().unwrap();
match event {
"heartbeat" => {
debug!("Received {} from {}", msg, EXCHANGE_NAME);
let ping = r#"{
"event": "ping",
"reqid": 9527
}"#;
MiscMessage::WebSocket(Message::Text(ping.to_string()))
}
"pong" => {
debug!("Received {} from {}", msg, EXCHANGE_NAME);
MiscMessage::Misc
}
"subscriptionStatus" => {
let status = obj.get("status").unwrap().as_str().unwrap();
match status {
"subscribed" | "unsubscribed" => {
info!("Received {} from {}", msg, EXCHANGE_NAME)
}
"error" => {
error!("Received {} from {}", msg, EXCHANGE_NAME);
let error_msg = obj.get("errorMessage").unwrap().as_str().unwrap();
if error_msg.starts_with("Currency pair not supported") {
panic!("Received {} from {}", msg, EXCHANGE_NAME)
}
}
_ => warn!("Received {} from {}", msg, EXCHANGE_NAME),
}
MiscMessage::Misc
}
"systemStatus" => {
let status = obj.get("status").unwrap().as_str().unwrap();
match status {
"maintenance" | "cancel_only" => {
warn!(
"Received {}, which means Kraken is in maintenance mode",
msg
);
std::thread::sleep(std::time::Duration::from_secs(20));
MiscMessage::Reconnect
}
_ => {
info!("Received {} from {}", msg, EXCHANGE_NAME);
MiscMessage::Misc
}
}
}
_ => {
warn!("Received {} from {}", msg, EXCHANGE_NAME);
MiscMessage::Misc
}
}
} else {
MiscMessage::Normal
}
}
fn to_raw_channel(channel: &str, pair: &str) -> String {
format!("{}{}{}", channel, CHANNEL_PAIR_DELIMITER, pair)
}
#[rustfmt::skip]
impl_trait!(Trade, KrakenWSClient, subscribe_trade, "trade", to_raw_channel);
#[rustfmt::skip]
impl_trait!(Ticker, KrakenWSClient, subscribe_ticker, "ticker", to_raw_channel);
#[rustfmt::skip]
impl_trait!(BBO, KrakenWSClient, subscribe_bbo, "spread", to_raw_channel);
impl<'a> OrderBook for KrakenWSClient<'a> {
fn subscribe_orderbook(&self, pairs: &[String]) {
let command = format!(
r#"{{"event":"subscribe","pair":{},"subscription":{{"name":"book", "depth":25}}}}"#,
serde_json::to_string(pairs).unwrap(),
);
let channels = vec![command];
self.client.subscribe(&channels);
}
}
impl<'a> OrderBookSnapshot for KrakenWSClient<'a> {
fn subscribe_orderbook_snapshot(&self, _pairs: &[String]) {
panic!("Kraken does NOT have orderbook snapshot channel");
}
}
impl<'a> Candlestick for KrakenWSClient<'a> {
fn subscribe_candlestick(&self, pairs: &[String], interval: u32) {
let valid_set: Vec<u32> = vec![1, 5, 15, 30, 60, 240, 1440, 10080, 21600]
.into_iter()
.map(|x| x * 60)
.collect();
if !valid_set.contains(&interval) {
let joined = valid_set
.into_iter()
.map(|x| (x / 60).to_string())
.collect::<Vec<String>>()
.join(",");
panic!("Kraken has intervals {}", joined);
}
let command = format!(
r#"{{"event":"subscribe","pair":{},"subscription":{{"name":"ohlc", "interval":{}}}}}"#,
serde_json::to_string(pairs).unwrap(),
interval / 60
);
let channels = vec![command];
self.client.subscribe(&channels);
}
}
define_client!(
KrakenWSClient,
EXCHANGE_NAME,
WEBSOCKET_URL,
channels_to_commands,
on_misc_msg,
None
);
#[cfg(test)]
mod tests {
#[test]
fn test_one_pair() {
assert_eq!(
r#"{"event":"subscribe","pair":["XBT/USD"],"subscription":{"name":"trade"}}"#,
super::name_pairs_to_command("trade", &vec!["XBT/USD".to_string()], true)
);
assert_eq!(
r#"{"event":"unsubscribe","pair":["XBT/USD"],"subscription":{"name":"trade"}}"#,
super::name_pairs_to_command("trade", &vec!["XBT/USD".to_string()], false)
);
}
#[test]
fn test_two_pairs() {
assert_eq!(
r#"{"event":"subscribe","pair":["XBT/USD","ETH/USD"],"subscription":{"name":"trade"}}"#,
super::name_pairs_to_command(
"trade",
&vec!["XBT/USD".to_string(), "ETH/USD".to_string()],
true
)
);
assert_eq!(
r#"{"event":"unsubscribe","pair":["XBT/USD","ETH/USD"],"subscription":{"name":"trade"}}"#,
super::name_pairs_to_command(
"trade",
&vec!["XBT/USD".to_string(), "ETH/USD".to_string()],
false
)
);
}
}