pair_generator.js

const exchUtils = require("./exchange_utils.js")

module.exports = {
	create: function(tokenName, marketName) {
		var _tokenName = tokenName
		var _marketName = marketName

		var _lastPrice = 0
		var _charts = {}

		var _profit = 0
		var _accountProfit = 0

		this.name = function() {
			return _tokenName + _marketName
		}

		this.tokenName = function() {
			return _tokenName
		}

		this.marketName = function() {
			return _marketName
		}

		this.chatName = function() {
			return "#" + _tokenName.toUpperCase() + "/" + _marketName.toUpperCase()
		}

		this.lastPrice = function() {
			return _lastPrice
		}

		this.chart = function(interval) {
			return _charts[interval]
		}

		this.initChartInterval = function(interval) {
			if(!_charts[interval]) {
				_charts[interval] = {}
				_charts[interval].watchers = 0
				_charts[interval].ticks = []
				_charts[interval].timestamp = 0
				_charts[interval].loading = false
			}
		}

		this.chartsNeedUpdate = function(intervals, maxTimeElapsedSec, updateIfNeed) {
			if(typeof intervals == "string") intervals = [intervals]

			var needUpdateAll = false
			for(var i = 0; i < intervals.length; ++i) {
				var interval = intervals[i]
				this.initChartInterval(interval)

				if(this.chartUpdatesActive(interval)) continue
				var currentTime = Date.now()
				if(currentTime - _charts[interval].timestamp < maxTimeElapsedSec * 1000) continue

				needUpdateAll = true

				if(updateIfNeed && !_charts[interval].loading) this.singleChartUpdate(interval)
			}

			return needUpdateAll
		}

		this.singleChartUpdate = function(interval, next) {
			this.initChartInterval(interval)

			if(_charts[interval].watchers && this.chartUpdatesActive(interval)) {
				if(next) next(null, _charts[interval].ticks)
				return
			}

			if(_charts[interval].loading) {
				if(next) next(null, [])
				return
			}

			_charts[interval].loading = true
			exchUtils.chartUpdate(this.name(), interval, function(error, pairName, ticks) {
				if(error) {
					console.log("Error fetching candlesticks", pairName, error)
					_charts[interval].loading = false
					if(next) next(error, [])
					return
				}

				var ticksArray = []
				for(var i = 0; i < ticks.length; ++i) {
					var tickJson = {}
					tickJson.timestamp = ticks[i][0]
					tickJson.open = ticks[i][1]
					tickJson.high = ticks[i][2]
					tickJson.low = ticks[i][3]
					tickJson.close = ticks[i][4]
					tickJson.volume = ticks[i][5]
					ticksArray.push(tickJson)
				}
				_charts[interval].ticks = ticksArray
				_charts[interval].timestamp = Date.now()
				_charts[interval].loading = false
				if(ticksArray.length) _lastPrice = ticksArray[ticksArray.length - 1].close

				if(next) next(error, _charts[interval].ticks)
			})
		}

		this.startChartUpdates = function(interval) {
			this.initChartInterval(interval)

			if(_charts[interval].loading) {
				return
			}

			_charts[interval].loading = true
			exchUtils.startChartUpdate(this.name(), interval, function(pairName, interval, chart) {
				var timestamps = Object.keys(chart)
				timestamps.sort()

				var newTicks = []
				for(var i = 0; i < timestamps.length; ++i) {
					var tick = chart[timestamps[i]]
					tick.timestamp = timestamps[i]
					newTicks.push(tick)
				}

				_charts[interval].ticks = newTicks
				_charts[interval].timestamp = Date.now()
				_charts[interval].loading = false

				if(newTicks.length) _lastPrice = newTicks[newTicks.length - 1].close
			})
		}

		this.stopChartUpdates = function(interval) {
			var websocketName = this.name().toLowerCase() + "@" + "kline_" + interval
			exchUtils.terminateWebsocket(websocketName)
		}

		this.addWatcherChartUpdates = function(intervals) {
			if(typeof intervals == "string") intervals = [intervals]

			for(var i = 0; i < intervals.length; ++i) {
				var interval = intervals[i]

				this.initChartInterval(interval)

				_charts[interval].watchers++

				if(_charts[interval].watchers == 1) {
					this.startChartUpdates(interval)
				}
			}
		}

		this.removeWatcherChartUpdates = function(intervals) {
			if(typeof intervals == "string") intervals = [intervals]

			for(var i = 0; i < intervals.length; ++i) {
				var interval = intervals[i]

				this.initChartInterval(interval)

				_charts[interval].watchers--

				if(!_charts[interval].watchers) {
					this.stopChartUpdates(interval)
				}
			}
		}

		this.chartUpdatesActive = function(intervals) {
			if(typeof intervals == "string") intervals = [intervals]

			var allActive = true
			for(var i = 0; i < intervals.length; ++i) {
				var interval = intervals[i]
				var websocketName = this.name().toLowerCase() + "@" + "kline_" + interval
				if(!exchUtils.websocketActive(websocketName) || _charts[interval].loading) {
					allActive = false
					break
				}
			}
			return allActive
		}

		this.ensureChartUpdates = function(intervals) {
			if(typeof intervals == "string") intervals = [intervals]

			for(var i = 0; i < intervals.length; ++i) {
				if(!this.chartUpdatesActive(intervals[i])) {
					this.startChartUpdates(intervals[i])
				}
			}
		}

		this.profit = function() {
			return _profit
		}

		this.addProfit = function(profit) {
			_profit += profit
		}

		this.accountProfit = function() {
			return _accountProfit
		}

		this.addAccountProfit = function(profit) {
			_accountProfit += profit
		}

		this.resetProfits = function() {
			_profit = 0
			_accountProfit = 0
		}
	}
}