// global variable
// Declare a chart object that configures the chart
var chart = {
    __isStock: true,
    tooltip: {
        xDateFormat: '%Y-%m-%d %H:%M:%S, %A'
    },
    title: {
        text: 'Profit and loss chart（detail）'
    },
    rangeSelector: {
        buttons: [{
            type: 'hour',
            count: 1,
            text: '1h'
        }, {
            type: 'hour',
            count: 2,
            text: '3h'
        }, {
            type: 'hour',
            count: 8,
            text: '8h'
        }, {
            type: 'all',
            text: 'All'
        }],
        selected: 0,
        inputEnabled: false
    },
    xAxis: {
        type: 'datetime'
    },
    yAxis: {
        title: {
            text: 'spread'
        },
        opposite: false,
    },
    series: [{
        name: "up",
        id: "line1,up",
        data: []
    }, {
        name: "middle",
        id: "line2,middle",
        data: []
    }, {
        name: "down",
        id: "line3,down",
        data: []
    }, {
        name: "basb",
        id: "line4,basb",
        data: []
    }, {
        name: "sabb",
        id: "line5,sabb",
        data: []
    }]
};
var ObjChart = Chart(chart); // Drawing object
var bars = []; // Store spread sequence
var oldTime = 0; // Record historical data timestamp

// Parameter
var tradeTypeA = "this_week"; // Arbitrage contract A
var tradeTypeB = "quarter"; // Arbitrage contract B
var dataLength = 10; //Length of indicator cycle
var timeCycle = 1; // The cycle of K-line
var name = "ETC"; // Currency type
var unit = 1; // Quantity of orders

// Basic data
function Data(tradeTypeA, tradeTypeB) { // input arbitrage contract A&B
    this.accountData = _C(exchange.GetAccount); // get account data
    this.positionData = _C(exchange.GetPosition); // get position data
    var recordsData = _C(exchange.GetRecords); //get k-line data
    exchange.SetContractType(tradeTypeA); // subscribe arbitrage contract A
    var depthDataA = _C(exchange.GetDepth); // deep data of arbitrage contract A
    exchange.SetContractType(tradeTypeB); // subscribe arbitrage contract B
    var depthDataB = _C(exchange.GetDepth); // deep data of arbitrage contract B
    this.time = recordsData[recordsData.length - 1].Time; // get the latest time data
    this.askA = depthDataA.Asks[0].Price; // the latest selling price of arbitrage contract A
    this.bidA = depthDataA.Bids[0].Price; // the latest buying price of arbitrage contract A
    this.askB = depthDataB.Asks[0].Price; // the latest selling price of arbitrage contract B
    this.bidB = depthDataB.Bids[0].Price; // the latest buying price of arbitrage contract B
    // Positive arbitrage spread(the latest selling price of contract A -the latest buying price of contract B )
    this.basb = depthDataA.Asks[0].Price - depthDataB.Bids[0].Price;
    // Reverse arbitrage spread(the latest buying price of contract A -the latest selling price of contract B )
    this.sabb = depthDataA.Bids[0].Price - depthDataB.Asks[0].Price;
}

// get position information
Data.prototype.mp = function (tradeType, type) {
    var positionData = this.positionData; // get position data
    for (var i = 0; i < positionData.length; i++) {
        if (positionData[i].ContractType == tradeType) {
            if (positionData[i].Type == type) {
                if (positionData[i].Amount > 0) {
                    return positionData[i].Amount;
                }
            }
        }
    }
    return false;
}

// Synthetize new K-line data and boll indicator data
Data.prototype.boll = function (num, timeCycle) {
    var self = {}; // Temporary object
    // the median of Positive arbitrage spread and reverse arbitrage spread
    self.Close = (this.basb + this.sabb) / 2;
    if (this.timeA == this.timeB) {
        self.Time = this.time;
    } // Comparing two depth data timestamps
    if (this.time - oldTime > timeCycle * 60000) {
        bars.push(self);
        oldTime = this.time;
    } // According to the specified time period, insert the spread data object in the K-line array.
    if (bars.length > num * 2) {
        bars.shift(); // Control K-line array length
    } else {
        return;
    }
    var boll = TA.BOLL(bars, num, 2); // Call the boll indicator in the Talib Library
    return {
        up: boll[0][boll[0].length - 1], // up rail of boll indicator
        middle: boll[1][boll[1].length - 1], // middle rail of boll indicator
        down: boll[2][boll[2].length - 1] // down rail of boll indicator
    } // Return a processed boll indicator data.
}

// place order
Data.prototype.trade = function (tradeType, type) {
    exchange.SetContractType(tradeType); // Resubscribe contract before placing order
    var askPrice, bidPrice;
    if (tradeType == tradeTypeA) { // if it's contract A
        askPrice = this.askA; // set askPrice
        bidPrice = this.bidA; // set bidPrice
    } else if (tradeType == tradeTypeB) { // if it's contract B
        askPrice = this.askB; // set askPrice
        bidPrice = this.bidB; // set bidPrice
    }
    switch (type) { // Match order mode
        case "buy":
            exchange.SetDirection(type); // Set order mode
            return exchange.Buy(askPrice, unit);
        case "sell":
            exchange.SetDirection(type); // Set order mode
            return exchange.Sell(bidPrice, unit);
        case "closebuy":
            exchange.SetDirection(type); // Set order mode
            return exchange.Sell(bidPrice, unit);
        case "closesell":
            exchange.SetDirection(type); // Set order mode
            return exchange.Buy(askPrice, unit);
        default:
            return false;
    }
}

// cancel order
Data.prototype.cancelOrders = function () {
    Sleep(500); // delay before canceling, because some exchanges you know...
    var orders = _C(exchange.GetOrders); // Get the array of pending orders
    if (orders.length > 0) { // if there is pending order
        for (var i = 0; i < orders.length; i++) { //check through the array of pending orders
            exchange.CancelOrder(orders[i].Id); //cancel pending orders one by one
            Sleep(500); //Delay 0.5 seconds
        }
        return false; // return false if pending orders have been cancelled
    }
    return true; //return true if there is no pending order
}

// handle holding single contract
Data.prototype.isEven = function () {
    var positionData = this.positionData; // get position data
    var type = null; // converse position direction 
    // If the length of the position array divided by some number and the remainder is 2, the result is not equal to 0 or the length of the position array is not equal to 2
    if (positionData.length % 2 != 0 || positionData.length != 2) {
        for (var i = 0; i < positionData.length; i++) { // check through the array of positions
            if (positionData[i].Type == 0) { // if it's long position
                type = 10; // Set order parameters
            } else if (positionData[i].Type == 1) { // if it's short position
                type = -10; // Set order parameters
            }
            // close all positions
            this.trade(positionData[i].ContractType, type, positionData[i].Amount);
        }
    }
}

// drawing chart
Data.prototype.drawingChart = function (boll) {
    var nowTime = new Date().getTime();
    ObjChart.add([0, [nowTime, boll.up]]);
    ObjChart.add([1, [nowTime, boll.middle]]);
    ObjChart.add([2, [nowTime, boll.down]]);
    ObjChart.add([3, [nowTime, this.basb]]);
    ObjChart.add([4, [nowTime, this.sabb]]);
    ObjChart.update(chart);
}

// trading condition
function onTick() {
    var data = new Data(tradeTypeA, tradeTypeB); // Create a base data object
    var accountStocks = data.accountData.Stocks; // account balance
    var boll = data.boll(dataLength, timeCycle); // get boll indicator data
    if (!boll) return; // return if there is no boll data
    // Spread description
    // basb = (the latest selling price of contract A - the latest buying price of contract B)
    // sabb = (the latest buying price of contract A - the latest selling price of contract B)
    if (data.sabb > boll.middle && data.sabb < boll.up) { // if sabb is higher than the middle rail
        if (data.mp(tradeTypeA, 0)) { // check if contract A has long positon before placing order
            data.trade(tradeTypeA, "closebuy"); // close long position of contract A
        }
        if (data.mp(tradeTypeB, 1)) { // check if contract B has short positon before placing order
            data.trade(tradeTypeB, "closesell"); // close short position of contract B
        }
    } else if (data.basb < boll.middle && data.basb > boll.down) { // if basb is lower than the middle rail
        if (data.mp(tradeTypeA, 1)) { // check if contract A has short positon before placing order
            data.trade(tradeTypeA, "closesell"); // close short position of contract A
        }
        if (data.mp(tradeTypeB, 0)) { // check if contract B has long positon before placing order
            data.trade(tradeTypeB, "closebuy"); // close long position of contract B
        }
    }
    if (accountStocks * Math.max(data.askA, data.askB) > 1) { // If there is balance in the account
        if (data.basb < boll.down) { // if basb spread is lower than the down rail
            if (!data.mp(tradeTypeA, 0)) { // check if contract A has long positon before placing order
                data.trade(tradeTypeA, "buy"); // open long position of contract A
            }
            if (!data.mp(tradeTypeB, 1)) { // check if contract B has short positon before placing order
                data.trade(tradeTypeB, "sell"); // open short position of contract B
            }
        } else if (data.sabb > boll.up) { // if sabb spread is higher than the up rail
            if (!data.mp(tradeTypeA, 1)) { // check if contract A has short positon before placing order
                data.trade(tradeTypeA, "sell"); // open short position of contract A
            }
            if (!data.mp(tradeTypeB, 0)) { // check if contract B has long positon before placing order
                data.trade(tradeTypeB, "buy"); // open long position of contract B
            }
        }
    }
    data.cancelOrders(); // cancel orders
    data.drawingChart(boll); // drawing chart
    data.isEven(); // process holding single contract
}

//enter function
function main() {
    // filter the information that is not very important in the console
    SetErrorFilter("429|GetRecords:|GetOrders:|GetDepth:|GetAccount|:Buy|Sell|timeout|Futures_OP");
    exchange.IO("currency", name + '_USDT'); //Set the cryptocurrency type to be traded
    ObjChart.reset(); //Empty the drawn charts before the program starts
    LogProfitReset(); //Empty the status bar information before the program starts
    while (true) { // Enter polling mode
        onTick(); // Execute onTick function
        Sleep(500); // sleep for o.5 seconds
    }
}