request-processor.js

/*
	This file is a node.js module.

	This is a sample implementation of UDF-compatible datafeed wrapper for Quandl (historical data) and yahoo.finance (quotes).
	Some algorithms may be incorrect because it's rather an UDF implementation sample
	then a proper datafeed implementation.
*/

/* global require */
/* global console */
/* global exports */
/* global process */

"use strict";

var version = '2.0.4';

var https = require("https");
var http = require("http");

var quandlCache = {};

var quandlCacheCleanupTime = 3 * 60 * 60 * 1000; // 3 hours
var quandlKeysValidateTime = 15 * 60 * 1000; // 15 minutes
var quandlMinimumDate = '1970-01-01';

// this cache is intended to reduce number of requests to Quandl
setInterval(function () {
	quandlCache = {};
	console.warn(dateForLogs() + 'Quandl cache invalidated');
}, quandlCacheCleanupTime);

function dateForLogs() {
	return (new Date()).toISOString() + ': ';
}

var defaultResponseHeader = {
	"Content-Type": "text/plain",
	'Access-Control-Allow-Origin': '*'
};

function sendJsonResponse(response, jsonData) {
	response.writeHead(200, defaultResponseHeader);
	response.write(JSON.stringify(jsonData));
	response.end();
}

function dateToYMD(date) {
	var obj = new Date(date);
	var year = obj.getFullYear();
	var month = obj.getMonth() + 1;
	var day = obj.getDate();
	return year + "-" + month + "-" + day;
}

var quandlKeys = process.env.QUANDL_API_KEY.split(','); // you should create a free account on quandl.com to get this key, you can set some keys concatenated with a comma
var invalidQuandlKeys = [];

function getValidQuandlKey() {
	for (var i = 0; i < quandlKeys.length; i++) {
		var key = quandlKeys[i];
		if (invalidQuandlKeys.indexOf(key) === -1) {
			return key;
		}
	}
	return null;
}

function markQuandlKeyAsInvalid(key) {
	if (invalidQuandlKeys.indexOf(key) !== -1) {
		return;
	}

	invalidQuandlKeys.push(key);

	console.warn(dateForLogs() + 'Quandl key invalidated ' + key);

	setTimeout(function() {
		console.log(dateForLogs() + "Quandl key restored: " + invalidQuandlKeys.shift());
	}, quandlKeysValidateTime);
}

function sendError(error, response) {
	response.writeHead(200, defaultResponseHeader);
	response.write("{\"s\":\"error\",\"errmsg\":\"" + error + "\"}");
	response.end();
}

function httpGet(datafeedHost, path, callback) {
	var options = {
		host: datafeedHost,
		path: path
	};

	function onDataCallback(response) {
		var result = '';

		response.on('data', function (chunk) {
			result += chunk;
		});

		response.on('end', function () {
			if (response.statusCode !== 200) {
				callback({ status: 'ERR_STATUS_CODE', errmsg: response.statusMessage || '' });
				return;
			}

			callback({ status: 'ok', data: result });
		});
	}

	var req = https.request(options, onDataCallback);

	req.on('socket', function (socket) {
		socket.setTimeout(5000);
		socket.on('timeout', function () {
			console.log(dateForLogs() + 'timeout');
			req.abort();
		});
	});

	req.on('error', function (e) {
		callback({ status: 'ERR_SOCKET', errmsg: e.message || '' });
	});

	req.end();
}

function convertQuandlHistoryToUDFFormat(data) {
	function parseDate(input) {
		var parts = input.split('-');
		return Date.UTC(parts[0], parts[1] - 1, parts[2]);
	}

	function columnIndices(columns) {
		var indices = {};
		for (var i = 0; i < columns.length; i++) {
			indices[columns[i].name] = i;
		}

		return indices;
	}

	var result = {
		t: [],
		c: [],
		o: [],
		h: [],
		l: [],
		v: [],
		s: "ok"
	};

	try {
		var json = JSON.parse(data);
		var datatable = json.datatable;
		var idx = columnIndices(datatable.columns);

		datatable.data
			.sort(function (row1, row2) {
				return parseDate(row1[idx.date]) - parseDate(row2[idx.date]);
			})
			.forEach(function (row) {
				result.t.push(parseDate(row[idx.date]) / 1000);
				result.o.push(row[idx.open]);
				result.h.push(row[idx.high]);
				result.l.push(row[idx.low]);
				result.c.push(row[idx.close]);
				result.v.push(row[idx.volume]);
			});

	} catch (error) {
		return null;
	}

	return result;
}

function proxyRequest(controller, options, response) {
	controller.request(options, function (res) {
		var result = '';

		res.on('data', function (chunk) {
			result += chunk;
		});

		res.on('end', function () {
			if (res.statusCode !== 200) {
				response.writeHead(200, defaultResponseHeader);
				response.write(JSON.stringify({
					s: 'error',
					errmsg: 'Failed to get news'
				}));
				response.end();
				return;
			}
			response.writeHead(200, defaultResponseHeader);
			response.write(result);
			response.end();
		});
	}).end();
}

function RequestProcessor(symbolsDatabase) {
	this._symbolsDatabase = symbolsDatabase;
}

function filterDataPeriod(data, fromSeconds, toSeconds) {
	if (!data || !data.t) {
		return data;
	}

	if (data.t[data.t.length - 1] < fromSeconds) {
		return {
			s: 'no_data',
			nextTime: data.t[data.t.length - 1]
		};
	}

	var fromIndex = null;
	var toIndex = null;
	var times = data.t;
	for (var i = 0; i < times.length; i++) {
		var time = times[i];
		if (fromIndex === null && time >= fromSeconds) {
			fromIndex = i;
		}
		if (toIndex === null && time >= toSeconds) {
			toIndex = time > toSeconds ? i - 1 : i;
		}
		if (fromIndex !== null && toIndex !== null) {
			break;
		}
	}

	fromIndex = fromIndex || 0;
	toIndex = toIndex ? toIndex + 1 : times.length;

	var s = data.s;

	if (toSeconds < times[0]) {
		s = 'no_data';
	}

	toIndex = Math.min(fromIndex + 1000, toIndex); // do not send more than 1000 bars for server capacity reasons

	return {
		t: data.t.slice(fromIndex, toIndex),
		o: data.o.slice(fromIndex, toIndex),
		h: data.h.slice(fromIndex, toIndex),
		l: data.l.slice(fromIndex, toIndex),
		c: data.c.slice(fromIndex, toIndex),
		v: data.v.slice(fromIndex, toIndex),
		s: s
	};
}

RequestProcessor.prototype._sendConfig = function (response) {

	var config = {
		supports_search: true,
		supports_group_request: false,
		supports_marks: true,
		supports_timescale_marks: true,
		supports_time: true,
		exchanges: [
			{
				value: "",
				name: "All Exchanges",
				desc: ""
			},
			{
				value: "NasdaqNM",
				name: "NasdaqNM",
				desc: "NasdaqNM"
			},
			{
				value: "NYSE",
				name: "NYSE",
				desc: "NYSE"
			},
			{
				value: "NCM",
				name: "NCM",
				desc: "NCM"
			},
			{
				value: "NGM",
				name: "NGM",
				desc: "NGM"
			},
		],
		symbols_types: [
			{
				name: "All types",
				value: ""
			},
			{
				name: "Stock",
				value: "stock"
			},
			{
				name: "Index",
				value: "index"
			}
		],
		supported_resolutions: ["D", "2D", "3D", "W", "3W", "M", '6M']
	};

	response.writeHead(200, defaultResponseHeader);
	response.write(JSON.stringify(config));
	response.end();
};


RequestProcessor.prototype._sendMarks = function (response) {
	var now = new Date();
	now = new Date(Date.UTC(now.getUTCFullYear(), now.getUTCMonth(), now.getUTCDate())) / 1000;
	var day = 60 * 60 * 24;

	var marks = {
		id: [0, 1, 2, 3, 4, 5],
		time: [now, now - day * 4, now - day * 7, now - day * 7, now - day * 15, now - day * 30],
		color: ["red", "blue", "green", "red", "blue", "green"],
		text: ["Today", "4 days back", "7 days back + Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.", "7 days back once again", "15 days back", "30 days back"],
		label: ["A", "B", "CORE", "D", "EURO", "F"],
		labelFontColor: ["white", "white", "red", "#FFFFFF", "white", "#000"],
		minSize: [14, 28, 7, 40, 7, 14]
	};

	response.writeHead(200, defaultResponseHeader);
	response.write(JSON.stringify(marks));
	response.end();
};

RequestProcessor.prototype._sendTime = function (response) {
	var now = new Date();
	response.writeHead(200, defaultResponseHeader);
	response.write(Math.floor(now / 1000) + '');
	response.end();
};

RequestProcessor.prototype._sendTimescaleMarks = function (response) {
	var now = new Date();
	now = new Date(Date.UTC(now.getUTCFullYear(), now.getUTCMonth(), now.getUTCDate())) / 1000;
	var day = 60 * 60 * 24;

	var marks = [
		{
			id: "tsm1",
			time: now,
			color: "red",
			label: "A",
			tooltip: ""
		},
		{
			id: "tsm2",
			time: now - day * 4,
			color: "blue",
			label: "D",
			tooltip: ["Dividends: $0.56", "Date: " + new Date((now - day * 4) * 1000).toDateString()]
		},
		{
			id: "tsm3",
			time: now - day * 7,
			color: "green",
			label: "D",
			tooltip: ["Dividends: $3.46", "Date: " + new Date((now - day * 7) * 1000).toDateString()]
		},
		{
			id: "tsm4",
			time: now - day * 15,
			color: "#999999",
			label: "E",
			tooltip: ["Earnings: $3.44", "Estimate: $3.60"]
		},
		{
			id: "tsm7",
			time: now - day * 30,
			color: "red",
			label: "E",
			tooltip: ["Earnings: $5.40", "Estimate: $5.00"]
		},
	];

	response.writeHead(200, defaultResponseHeader);
	response.write(JSON.stringify(marks));
	response.end();
};


RequestProcessor.prototype._sendSymbolSearchResults = function (query, type, exchange, maxRecords, response) {
	if (!maxRecords) {
		throw "wrong_query";
	}

	var result = this._symbolsDatabase.search(query, type, exchange, maxRecords);

	response.writeHead(200, defaultResponseHeader);
	response.write(JSON.stringify(result));
	response.end();
};

RequestProcessor.prototype._prepareSymbolInfo = function (symbolName) {
	var symbolInfo = this._symbolsDatabase.symbolInfo(symbolName);

	if (!symbolInfo) {
		throw "unknown_symbol " + symbolName;
	}

	return {
		"name": symbolInfo.name,
		"exchange-traded": symbolInfo.exchange,
		"exchange-listed": symbolInfo.exchange,
		"timezone": "America/New_York",
		"minmov": 1,
		"minmov2": 0,
		"pointvalue": 1,
		"session": "0930-1630",
		"has_intraday": false,
		"has_no_volume": symbolInfo.type !== "stock",
		"description": symbolInfo.description.length > 0 ? symbolInfo.description : symbolInfo.name,
		"type": symbolInfo.type,
		"supported_resolutions": ["D", "2D", "3D", "W", "3W", "M", "6M"],
		"pricescale": 100,
		"ticker": symbolInfo.name.toUpperCase()
	};
};

RequestProcessor.prototype._sendSymbolInfo = function (symbolName, response) {
	var info = this._prepareSymbolInfo(symbolName);

	response.writeHead(200, defaultResponseHeader);
	response.write(JSON.stringify(info));
	response.end();
};

RequestProcessor.prototype._sendSymbolHistory = function (symbol, startDateTimestamp, endDateTimestamp, resolution, response) {
	function sendResult(content) {
		var header = Object.assign({}, defaultResponseHeader);
		header["Content-Length"] = content.length;
		response.writeHead(200, header);
		response.write(content, null, function () {
			response.end();
		});
	}

	function secondsToISO(sec) {
		if (sec === null || sec === undefined) {
			return 'n/a';
		}
		return (new Date(sec * 1000).toISOString());
	}

	function logForData(data, key, isCached) {
		var fromCacheTime = data && data.t ? data.t[0] : null;
		var toCacheTime = data && data.t ? data.t[data.t.length - 1] : null;
		console.log(dateForLogs() + "Return QUANDL result" + (isCached ? " from cache" : "") + ": " + key + ", from " + secondsToISO(fromCacheTime) + " to " + secondsToISO(toCacheTime));
	}

	console.log(dateForLogs() + "Got history request for " + symbol + ", " + resolution + " from " + secondsToISO(startDateTimestamp)+ " to " + secondsToISO(endDateTimestamp));

	// always request all data to reduce number of requests to quandl
	var from = quandlMinimumDate;
	var to = dateToYMD(Date.now());

	var key = symbol + "|" + from + "|" + to;

	if (quandlCache[key]) {
		var dataFromCache = filterDataPeriod(quandlCache[key], startDateTimestamp, endDateTimestamp);
		logForData(dataFromCache, key, true);
		sendResult(JSON.stringify(dataFromCache));
		return;
	}

	var quandlKey = getValidQuandlKey();

	if (quandlKey === null) {
		console.log(dateForLogs() + "No valid quandl key available");
		sendError('No valid API Keys available', response);
		return;
	}

	var address = "/api/v3/datatables/WIKI/PRICES.json" +
		"?api_key=" + quandlKey + // you should create a free account on quandl.com to get this key
		"&ticker=" + symbol +
		"&date.gte=" + from +
		"&date.lte=" + to;

	console.log(dateForLogs() + "Sending request to quandl  " + key + ". url=" + address);

	httpGet("www.quandl.com", address, function (result) {
		if (response.finished) {
			// we can be here if error happened on socket disconnect
			return;
		}

		if (result.status !== 'ok') {
			if (result.status === 'ERR_SOCKET') {
				console.log('Socket problem with request: ' + result.errmsg);
				sendError("Socket problem with request " + result.errmsg, response);
				return;
			}

			console.error(dateForLogs() + "Error response from quandl for key " + key + ". Message: " + result.errmsg);
			markQuandlKeyAsInvalid(quandlKey);
			sendError("Error quandl response " + result.errmsg, response);
			return;
		}

		console.log(dateForLogs() + "Got response from quandl  " + key + ". Try to parse.");
		var data = convertQuandlHistoryToUDFFormat(result.data);
		if (data === null) {
			var dataStr = typeof result === "string" ? result.slice(0, 100) : result;
			console.error(dateForLogs() + " failed to parse: " + dataStr);
			sendError("Invalid quandl response", response);
			return;
		}

		if (data.t.length !== 0) {
			console.log(dateForLogs() + "Successfully parsed and put to cache " + data.t.length + " bars.");
			quandlCache[key] = data;
		} else {
			console.log(dateForLogs() + "Parsing returned empty result.");
		}

		var filteredData = filterDataPeriod(data, startDateTimestamp, endDateTimestamp);
		logForData(filteredData, key, false);
		sendResult(JSON.stringify(filteredData));
	});
};

RequestProcessor.prototype._quotesQuandlWorkaround = function (tickersMap) {
	var from = quandlMinimumDate;
	var to = dateToYMD(Date.now());

	var result = {
		s: "ok",
		d: [],
		source: 'Quandl',
	};

	Object.keys(tickersMap).forEach(function(symbol) {
		var key = symbol + "|" + from + "|" + to;
		var ticker = tickersMap[symbol];

		var data = quandlCache[key];
		var length = data === undefined ? 0 : data.c.length;

		if (length > 0) {
			var lastBar = {
				o: data.o[length - 1],
				h: data.o[length - 1],
				l: data.o[length - 1],
				c: data.o[length - 1],
				v: data.o[length - 1],
			};

			result.d.push({
				s: "ok",
				n: ticker,
				v: {
					ch: 0,
					chp: 0,

					short_name: symbol,
					exchange: '',
					original_name: ticker,
					description: ticker,

					lp: lastBar.c,
					ask: lastBar.c,
					bid: lastBar.c,

					open_price: lastBar.o,
					high_price: lastBar.h,
					low_price: lastBar.l,
					prev_close_price: length > 1 ? data.c[length - 2] : lastBar.o,
					volume: lastBar.v,
				}
			});
		}
	});

	return result;
};

RequestProcessor.prototype._sendQuotes = function (tickersString, response) {
	var tickersMap = {}; // maps YQL symbol to ticker

	var tickers = tickersString.split(",");
	[].concat(tickers).forEach(function (ticker) {
		var yqlSymbol = ticker.replace(/.*:(.*)/, "$1");
		tickersMap[yqlSymbol] = ticker;
	});

	sendJsonResponse(response, this._quotesQuandlWorkaround(tickersMap));
	console.log("Quotes request : " + tickersString + ' processed from quandl cache');
};

RequestProcessor.prototype._sendNews = function (symbol, response) {
	var options = {
		host: "feeds.finance.yahoo.com",
		path: "/rss/2.0/headline?s=" + symbol + "&region=US&lang=en-US"
	};

	proxyRequest(https, options, response);
};

RequestProcessor.prototype._sendFuturesmag = function (response) {
	var options = {
		host: "www.oilprice.com",
		path: "/rss/main"
	};

	proxyRequest(http, options, response);
};

RequestProcessor.prototype.processRequest = function (action, query, response) {
	try {
		if (action === "/config") {
			this._sendConfig(response);
		}
		else if (action === "/symbols" && !!query["symbol"]) {
			this._sendSymbolInfo(query["symbol"], response);
		}
		else if (action === "/search") {
			this._sendSymbolSearchResults(query["query"], query["type"], query["exchange"], query["limit"], response);
		}
		else if (action === "/history") {
			this._sendSymbolHistory(query["symbol"], query["from"], query["to"], query["resolution"].toLowerCase(), response);
		}
		else if (action === "/quotes") {
			this._sendQuotes(query["symbols"], response);
		}
		else if (action === "/marks") {
			this._sendMarks(response);
		}
		else if (action === "/time") {
			this._sendTime(response);
		}
		else if (action === "/timescale_marks") {
			this._sendTimescaleMarks(response);
		}
		else if (action === "/news") {
			this._sendNews(query["symbol"], response);
		}
		else if (action === "/futuresmag") {
			this._sendFuturesmag(response);
		} else {
			response.writeHead(200, defaultResponseHeader);
			response.write('Datafeed version is ' + version +
				'\nValid keys count is ' + String(quandlKeys.length - invalidQuandlKeys.length) +
				'\nCurrent key is ' + (getValidQuandlKey() || '').slice(0, 3) +
				(invalidQuandlKeys.length !== 0 ? '\nInvalid keys are ' + invalidQuandlKeys.reduce(function(prev, cur) { return prev + cur.slice(0, 3) + ','; }, '') : ''));
			response.end();
		}
	}
	catch (error) {
		sendError(error, response);
		console.error('Exception: ' + error);
	}
};

exports.RequestProcessor = RequestProcessor;