import concat from "lodash/concat";
import uniq from "lodash/uniq";
import find from "lodash/find";
import sampleSize from "lodash/sampleSize";
import keys from "lodash/keys";

export default class {
    constructor() {
        this.subscribers = {};
        this.timestamp = new Date();

        // create the initial state of data
        this.initialiseTickerData();
    }

    addSubscriber(subscriber, symbol) {
        if (!this.subscribers[symbol]) {
            this.subscribers[symbol] = [];
        }
        this.subscribers[symbol].push(subscriber);

        if (!this.updateInterval) {
            this.updateInterval = setInterval(this.applyDeltasToTickerData.bind(this), 500);
        }
    }

    removeSubscriber(subscriber, symbol) {
        let subscribers = this.subscribers[symbol];
        subscribers.splice(subscribers.indexOf(subscriber), 1);
    }

    removeSubscribers() {
        this.subscribers = {};
    }

    getTicker(symbol) {
        return this.tickerData[symbol];
    }

    getExchanges() {
        return EXCHANGES;
    }

    getExchangeInformation(exchangeName) {
        return find(EXCHANGES, (exchange) => {
            return exchange.symbol === exchangeName;
        })
    }

    getTickerDetail(symbol) {
        return this.createTickerDetail(symbol);
    }

    /*
     * the rest of this class exists primarily to create mock data - it can safely be ignored
     * as it is secondary to the main ideas being demonstrated by the rest of the application
     */
    initialiseTickerData() {
        this.tickerData = {};

        const allSymbols = uniq(concat(NASDAQ_SYMBOLS, LSE_SYMBOLS, JSE_SYMBOLS, DE_SYMBOLS));
        allSymbols.forEach((symbol) => {
            this.tickerData[symbol] = this.generateTickerRow(symbol);
        });
    }

    generateTickerRow(symbol) {
        let price = this.random(10, 600);
        return {
            symbol,
            price,
            bid: price - this.random(1, 3),
            ask: price + this.random(1, 3),
            recommendation: ['Buy', 'Hold', 'Sell'][Math.floor(this.random(0, 2))]
        }
    }

    random(min, max) {
        return parseFloat((Math.random() * (max - min + 1) + min))
    }

    applyDeltasToTickerData() {
        let symbols = keys(this.subscribers);
        let properties = ['price', 'bid', 'ask'];

        let symbolsToAlter = sampleSize(symbols, symbols.length / 4);
        let propertyToAlter = sampleSize(properties, 1);

        symbolsToAlter.forEach((symbol) => {
            this.tickerData[symbol] = {
                symbol,
                price: this.tickerData[symbol].price,
                bid: this.tickerData[symbol].bid,
                ask: this.tickerData[symbol].ask
            };

            this.tickerData[symbol][propertyToAlter] = +this.tickerData[symbol][propertyToAlter] + this.random(-2, 2);
        });

        symbols.forEach((symbol) => {
            this.subscribers[symbol].forEach((subscriber) => {
                subscriber(this.tickerData[symbol]);
            });
        });
    }

    formatNumber(input) {
        return input.toFixed(2);
    }

    formatWithDecimalPlaces(x) {
        return x.toString().replace(/\B(?=(\d{3})+(?!\d))/g, ",");
    }

    createTickerDetail(symbol) {
        let ticker = this.getTicker(symbol);
        let currentPrice = ticker.price;
        let tenthOfCurrentPrice = currentPrice / 10;
        let previousPrice = +currentPrice + this.random(-tenthOfCurrentPrice, tenthOfCurrentPrice);

        let twentiethOfCurrentPrice = currentPrice / 20;
        let yearAgoPrice = this.random(-twentiethOfCurrentPrice, twentiethOfCurrentPrice);

        let range = `${this.formatNumber(previousPrice)} - ${this.formatNumber(currentPrice)}`;
        let fiftyTwoWeek = `${this.formatNumber(yearAgoPrice)} - ${this.formatNumber(currentPrice)}`;

        let open = this.formatNumber(ticker.bid); // not the same, but will do for demo purposes

        let vol = this.formatWithDecimalPlaces(this.random(5000, 20000).toFixed(2));
        let avg = `${this.formatNumber(this.random(10, 30))}M`;

        let dividend = this.random(0, 1).toFixed(2);
        let yld = this.random(1, 2).toFixed(2);

        let eps = this.random(5, 10).toFixed(2);

        let shares = `${this.random(3000, 10000).toFixed(2)}M`;

        let marketCap = `${this.random(100000, 900000).toFixed(2)}M`;

        let historicalData = this.generateHistoricalData(100, this.timestamp, currentPrice);

        return {
            pricingDelta: {
                currentPrice,
                previousPrice
            },
            timestamp: this.timestamp.toDateString(),
            tickerSummary: {
                range,
                fiftyTwoWeek,
                open,
                vol,
                avg,
                dividend,
                yld,
                eps,
                shares,
                marketCap
            },
            historicalData
        }
    }

    formatDate(date) {
        return `${date.getDate()}-${date.getMonth() + 1}-${date.getFullYear()}`;
    }

    generateHistoricalData(numberOfPoints, endDate, endPrice) {
        let historicalData = [{
            "date": this.formatDate(endDate),
            "price": endPrice
        }
        ];

        let numberOfTransitions = 15;
        let pointsPerTransition = numberOfPoints / numberOfTransitions;

        let lastDate = endDate;
        let lastPrice = endPrice;
        for (let transition = 0; transition < numberOfTransitions; transition++) {
            let swing = (Math.random() >= 0.5) ? 1 : -1;

            for (let i = 0; i <= pointsPerTransition; i++) {
                lastDate.setDate(lastDate.getDate() - 1);
                lastPrice = lastPrice + (swing * this.random(-1, 10));
                lastPrice = lastPrice < 0 ? 0 : lastPrice;

                historicalData.splice(0, 0, ({
                    "date": this.formatDate(lastDate),
                    "price": lastPrice
                }));
            }
        }

        return historicalData;
    }
}

const NASDAQ_SYMBOLS = [
    "SNCL.L",
    "RNK.L",
    "SWJ.L",
    "JDT.L",
    "UANC.L",
    "SDP.L",
    "HSBA.L",
    "XPL.L",
    "KLR.L",
    "SSE.L",
    "JSI.L",
    "UBMN.L",
    "WPC.L",
    "VTC.L",
    "UTG.L",
    "DOR.L",
    "44RS.L",
    "GPOR.L",
    "ASL.L",
    "40JP.L",
    "133716",
    "PJF.L",
    "MLC.L",
    "137817",
    "GHE.L",
    "PML.L",
    "SBRY.L",
    "LEN.L",
    "STS.L",
    "138654",
    "PTEC.L"
];

const LSE_SYMBOLS = [
    "PVG.L",
    "SN.L,",
    "SWJ.L",
    "JDT.L",
    "UANC.L",
    "SDP.L",
    "HSBA.L",
    "XPL.L",
    "KLR.L",
    "SSE.L",
    "JSI.L",
    "UBMN.L",
    "DLN.L",
    "SIR.L",
    "SEC.L",
    "DOR.L",
    "44RS.L",
    "GPOR.L",
    "ASL.L",
    "40JP.L",
    "133716",
    "PJF.L",
    "MLC.L",
    "137817",
    "GHE.L",
    "PML.L",
    "SBRY.L",
    "LEN.L",
    "MAV4.L",
    "GLEN.L",
    "EDGD.L",
];

const JSE_SYMBOLS = [
    "ECV.L",
    "MHN.L",
    "SWJ.L",
    "JDT.L",
    "UANC.L",
    "PLAZ.L",
    "CLDN.L",
    "XPL.L",
    "KLR.L",
    "SSE.L",
    "JSI.L",
    "UBMN.L",
    "WPC.L",
    "VTC.L",
    "UTG.L",
    "DOR.L",
    "44RS.L",
    "GPOR.L",
    "ASL.L",
    "40JP.L",
    "133716",
    "CRW.L",
    "JPR.L",
    "UTLC.L",
    "GHS.L",
    "PML.L",
    "SBRY.L",
    "LEN.L",
    "STS.L",
    "138654",
    "RWS.L"
];

const DE_SYMBOLS = [
    "ECV.L",
    "MHN.L",
    "SWJ.L",
    "JDT.L",
    "UANC.L",
    "SDP.L",
    "KBC.L",
    "VM.L,",
    "KLR.L",
    "SSE.L",
    "JSI.L",
    "UBMN.L",
    "WPC.L",
    "VTC.L",
    "UTG.L",
    "DOR.L",
    "44RS.L",
    "GPOR.L",
    "ASL.L",
    "40JP.L",
    "133716",
    "PJF.L",
    "MLC.L",
    "DPV6.L",
    "LMIN.L",
    "PML.L",
    "SBRY.L",
    "LEN.L",
    "STS.L",
    "BKIR.L",
    "AFMF.L",
];

const EXCHANGES = [
    {name: 'Nasdaq Stock Market', symbol: 'NASDAQ', supportedStocks: NASDAQ_SYMBOLS},
    {name: 'London Stock Exchange', symbol: 'LSE', supportedStocks: LSE_SYMBOLS},
    {name: 'Japan Exchange Group', symbol: 'JSE', supportedStocks: JSE_SYMBOLS},
    {name: 'Deutsche Börse', symbol: 'DE', supportedStocks: DE_SYMBOLS}
];