'use strict'
const Promise = require('bluebird')
const Debug = require('debug')
const flatPromise = require('flat-promise')
const MAX_SUBMIT_ATTEMPTS = 10
/**
* Generates a set of helpers to be used during algo order execution; these
* helpers are saved on the AO instance and provided to all event handlers.
*
* @param {object} state - algo order instance state
* @param {object} adapter - exchange adapter
* @returns {object} helpers
* @private
*/
const genHelpers = (state = {}, adapter) => {
const { id, gid } = state
const debug = Debug(`bfx:hf:algo:${id}:${gid}`)
const logHelperCall = (fmt, ...data) => {
const { DEBUG_TRACE } = process.env
if (DEBUG_TRACE) {
const { stack } = new Error()
debug(`${fmt} [%s]`, ...data, stack.split('\n')[3].trim())
} else {
debug(fmt, ...data)
}
}
const pendingSubscriptionResponses = {}
adapter.m.on('ws2:event:subscribed', (event) => {
const subscription = Object.values(pendingSubscriptionResponses)
.find(({ channel, payload }) =>
channel === event.channel &&
Object.entries(payload).every(([key, value]) => {
return value === event[key]
})
)
if (!subscription) {
return
}
const { eid, resolve, timeout } = subscription
if (timeout) {
clearTimeout(timeout)
}
delete pendingSubscriptionResponses[eid]
resolve()
})
/**
* @module Helpers
*
* @description
* ### AO Event Handlers & Helpers
* All event handlers receive the same arguments: `(instance = {}, ...args)`.
* The instance contains two objects, `{ state = {}, h = {} }` with `state`
* being the current AO state, and `h` being a helper object.
*
* The provided helpers are:
* * `clearAllTimeouts()` - clears all pending order submit/cancel timeouts
*
* * `debug(str, ...args)` - for logging information to the console, tagged
* by AO GID
*
* * `emitSelf(eventName, ...args)` - triggers an event on the 'self' section
*
* * `emit(eventName, ...args)` - raw event emitter, i.e. `emit('life:start')`
*
* * `notifyUI(level, message)` - generates and sends a notification which
* appears on the Bitfinex UI
*
* * `cancelOrder(state, order)` - takes current algo state and cancels the
* provided order
*
* * `submitOrderWithDelay(state, delay, order)` - takes current algo state,
* submits a new order, delay in ms
*
* * `declareEvent(instance, host, eventName, path)` - declares an internal
* AO event, see section below
*
* * `declareChannel(instance, host, channel, filter)` - declares a required
* data channel, see section below
*
* * `updateState(instance, update)` - update the current state for an AO
* instance
*/
return {
/**
* Clear all timeouts for pending subscriptions, called
* automatically by the algo host on teardown.
*/
clearAllTimeouts: () => {
for (const [eid, pendingSubscription] of Object.entries(pendingSubscriptionResponses)) {
if (pendingSubscription.timeout) {
clearTimeout(pendingSubscription.timeout)
}
delete pendingSubscriptionResponses[eid]
pendingSubscription.resolve()
}
},
timeout: (ms) => {
let id = null
const p = new Promise((resolve) => {
id = setTimeout(resolve, ms)
})
return [id, () => p]
},
/**
* Logs a string to the console, tagged by AO id/gid
*
* @param {string} str - format string
* @param {...any} args - passed to debug()
* @example
* debug('submitting order %s in %dms', order.toString(), delay)
*/
debug: (str, ...args) => {
debug(str, ...args)
},
/**
* Triggeres an event on the 'self' section
*
* @param {string} eventName - name of event to emit
* @param {...any} eventArgs - args passed to all handlers
* @returns {Promise} p - resolves when all handlers complete
* @example
* await emitSelf('submit_orders')
*/
emitSelf: async (eventName, ...eventArgs) => {
logHelperCall('emitSelf: %s', eventName)
return state.ev.emit(`self:${eventName}`, ...eventArgs)
},
/**
* Triggers a generic event
*
* @param {string} eventName - name of event to emit
* @param {...any} eventArgs - args passed to all handlers
* @returns {Promise} p - resolves when all handlers complete
* @example
* await emit('exec:order:submit:all', gid, [order], submitDelay)
*/
emit: async (eventName, ...eventArgs) => {
logHelperCall('emit %s', eventName)
return state.ev.emit(eventName, ...eventArgs)
},
/**
* Triggers an UI notification, sent out via the active websocket connection
*
* @param {string} level - 'info', 'success', 'error', 'warning'
* @param {string} message - notification content
* @returns {Promise} p - resolves when all handlers complete
* @example
* await notifyUI('info', `Scheduled tick in ${delay}s`)
*/
notifyUI: async (level, message) => {
logHelperCall('notify %s: %s', level, message)
await state.ev.emit('notify', gid, level, message)
},
/**
*
* @param {Object} state
* @param {Object} options
* @param {boolean} [options.fireAndForget]
* @param {number} [options.timeout]
* @returns Promise
*/
subscribeDataChannels: (state = {}, options = {}) => {
const { channels = [], gid, connection } = state
return Promise.all(
channels.map(({ channel, filter: payload }) => {
debug('subscribing to channel %j (filter: %) [AO gid %d]', channel, payload, gid)
adapter.subscribe(connection, channel, payload)
if (options.fireAndForget) {
return Promise.resolve()
}
const { promise, resolve, reject } = flatPromise()
const eid = Math.random()
const timeout = options.timeout &&
setTimeout(
() => {
delete pendingSubscriptionResponses[eid]
reject(new Error(`Subscription to channel '${channel}' timed out`))
},
options.timeout
)
pendingSubscriptionResponses[eid] = {
eid,
channel,
payload,
resolve,
timeout
}
return promise
})
)
},
/**
* Cancels the provided order instantly, and removes it from the active
* order set.
*
* @param {object} state - current AO instance state
* @param {object} order - order model or array
* @returns {object} nextState
* @example
* await cancelOrder(state, order)
*/
cancelOrder: async (state = {}, order) => {
logHelperCall('cancelOrder: %s', order.toString())
const { connection, orders = {} } = state
const {
[order.cid + '']: knownOrder, // eslint-disable-line
...otherOrders
} = orders
// NOTE: No await, in order to update cancelled order set immediately
adapter.cancelOrder(connection, order).then((order) => { // eslint-disable-line
debug(
'order successfully cancelled (id: %s, cid: %s): %s %f @ %f',
order.id, order.cid, order.type, order.amountOrig, order.price
)
}).catch((notification) => {
debug(
'received error while canceling order(id: %s, cid: %s): %s %f @ %f [ERROR: %O]',
order.id, order.cid, order.type, order.amountOrig, order.price, notification
)
})
return {
...state,
orders: otherOrders,
cancelledOrders: {
...state.cancelledOrders,
[order.cid + '']: order
}
}
},
sendPing: async (state = {}) => {
const { connection } = state
logHelperCall(
'sending ping to get server time'
)
const data = await adapter.sendPing(connection)
return data
},
/**
* Submits an order after a delay, and adds it to the active order set on
* the AO state. Emits errors if the order fails to submit; retries up to
* MAX_SUBMIT_ATTEMPTS in the case of balance evaluation errors.
*
* @param {object} state - current AO instance state
* @param {number} delay - delay in milliseconds
* @param {object} order - order model
* @param {number} attempt - attempt count, max is 10 (set as a constant)
* @returns {object} nextState
* @example
* await submitOrderWithDelay(state, 100, order)
*/
submitOrderWithDelay: async (state = {}, delay, order, attempt = 1) => {
logHelperCall(
'submitOrderWithDelay (%dms, attempt %d): %s',
delay, attempt, order.toString()
)
if (attempt > MAX_SUBMIT_ATTEMPTS) { // note state assumed already patched
return state
}
const { connection } = state
const orderPatch = {
[order.cid + '']: order
}
// Note that we don't wait for the order to submit here, since it might
// fill immediately triggering a fill event before we patch the state
// orders/allOrders objects
adapter.submitOrderWithDelay(connection, delay, order).then((order) => { // eslint-disable-line
debug(
'order successfully submitted: %s %f @ %f %s',
order.type, order.amountOrig, order.price, order.status
)
}).catch(async (notification) => {
const text = notification.text || notification
debug('%s', text)
if (/minimum size/.test(text)) {
await state.ev.emit('error:minimum_size', gid, order, { text })
} else if (/balance/.test(text)) {
await state.ev.emit('error:insufficient_balance', gid, order, { text })
} else if (/evaluate/.test(text)) {
if (attempt === MAX_SUBMIT_ATTEMPTS) {
await state.ev.emit('error:evaluate_balance', gid, order, { text })
} else {
const retryDelay = Math.max(500, delay + 250) // min 0.5s, increasing
await adapter.submitOrderWithDelay(connection, retryDelay, order)
}
} else {
await state.ev.emit('error:unknown_error', gid, order, { text })
}
})
return {
...state,
allOrders: { // track beyond close
...state.allOrders,
...orderPatch
},
orders: {
...state.orders,
...orderPatch
}
}
},
/**
* Hooks up the listener for a new event on the 'self' section
*
* @param {object} instance - full AO instance, with state/h
* @param {object} aoHost - algo host instance
* @param {string} eventName - name of event to declare
* @param {string} path - on the 'self' section
* @example
* declareEvent(instance, host, 'self:interval_tick', 'interval_tick')
*/
declareEvent: (instance = {}, aoHost, eventName, path) => {
const { state = {} } = instance
const { ev } = state
const handler = aoHost.onAOSelfEvent.bind(aoHost, instance, path)
logHelperCall('declareEvent: %s target %s', eventName, path)
ev.on(eventName, handler)
},
/**
* Assigns a data channel to the provided AO instance
*
* @param {object} instance - full AO instance, with state/h
* @param {object} aoHost - unused, here for common signature
* @param {string} channel - channel name, i.e. 'ticker'
* @param {object} filter - channel spec, i.e. { symbol: 'tBTCUSD' }
* @returns {object} nextState
* @example
* await declareChannel(instance, host, 'trades', { symbol })
*/
declareChannel: async (instance = {}, aoHost, channel, filter) => {
const { h = {}, state = {} } = instance
const { gid } = state
const { emit } = h
logHelperCall(
'declareChannel: %s filter %s', channel,
Object.keys(filter).map(k => `${k}=${filter[k]}`).join(', ')
)
await emit('channel:assign', gid, channel, filter)
return instance.state // updated ref
},
/**
* Updates the state for the provided AO instance
*
* @param {object} instance - full AO instance, with state/h
* @param {object} update - new state
* @returns {object} nextState
* @example
* await updateState(instance, { remainingAmount })
*/
updateState: async (instance = {}, update = {}) => {
const { h = {}, state = {} } = instance
const { gid } = state
const { emit } = h
logHelperCall('updateState')
await emit('state:update', gid, update)
return instance.state // updated ref
}
}
}
module.exports = genHelpers