Stage 2: Websocket Management

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const ws = new WebSocket('wss://demo.tradovateapi.com/v1/websocket');
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ws.onopen = function() {
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    // Send authentication message
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    const authMessage = `authorize\n0\n\n${accessToken}`;
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    ws.send(authMessage);
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};
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ws.onmessage = function(event) {
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    const data = JSON.parse(event.data);
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    if (data.i === 0) {
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        // Authentication response
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        console.log('Authentication successful:', data);
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    }
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};

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// Track last message time
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let lastMessageTime = new Date().getTime();
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ws.onmessage = function(event) {
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    const timestamp = new Date().getTime();
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    if(timestamp - lastMessageTime > 2500) {
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        ws.send('[]'); // Empty frame is a heartbeat in our protocol
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        lastMessageTime = timestamp; // Update last message time
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    }
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    // carry on with message handling
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    // ...
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};

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// Connect to the websocket
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const ws = new WebSocket('wss://demo.tradovateapi.com/v1/websocket');
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const requestBody = {
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    splitResponses: true,
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    // Optional, define sharding expression
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    shardingExpression: {
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        expressionType: 'modUserId', // | 'modAccountId'
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        divisor: 1,   // each instance should have the same divisor
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        remainder: 0, // modulus of the ID of user or account to process on this instance
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    },
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    entityTypes: [
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        'account',
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        'accountRiskStatus',
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        'cashBalance',
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        'commandReport',
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        'command',
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        'executionReport',
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        'fill', 
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        'fillPair', 
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        'order',
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        'orderStrategy', 
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        'position', 
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        'product', 
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        'user'
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    ],
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}
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ws.onopen = function() {
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    ws.send(`authorize\n0\n\n${accessToken}`);
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}
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ws.onmessage = function(event) {
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    const type = event.data.slice(0, 1);
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    let data = null;
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    if(type === 'a') {
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        data = JSON.parse(event.data.slice(1));
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    }
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    if(data.i === 0) {
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        // Authentication response
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        console.log('Authentication successful:', data);
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        // Send syncrequest
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        ws.send(`user/syncrequest\n1\n\n${JSON.stringify(requestBody)}`);
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    }
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}
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ws.onerror = function(event) {
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    console.error('WebSocket error:', event);
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}

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const send = requestData => {
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    return new Promise((res, rej) => {
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        let i = ++lastId;
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        let race = setTimeout(() => { reject(new Error('Request timeout'))}, 30000);
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        function handler(event) {
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            const type = event.data.slice(0, 1);
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            if(type === 'a') {
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                const data = JSON.parse(event.data.slice(1));
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                // data is always an array
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                for(const datum of data) {
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                    if(datum.i === i) {
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                        if(datum.d && 'p-ticket' in datum.d) {
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                            const pTicket = datum.d['p-ticket'];
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                            const pTime = datum.d['p-time'];
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                            const pCaptcha = datum.d['p-captcha'];
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                            if(pCaptcha) {
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                                // Handle captcha, if you receive it you have been locked out for 1 hour
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                                console.error('p-captcha received. Operations locked for 1 hour.');
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                                return;
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                            } else {
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                                // Handle rate limiting with P-Ticket, resend the request 
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                                // with the p-ticket after p-time seconds.
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                                setTimeout(() => {
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                                    send({
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                                        ...requestData, 
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                                        body: { ...requestData.body, 'p-ticket': pTicket }
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                                    });
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                                }, pTime * 1000);
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                                ws.removeEventListener('message', handler);
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                            }
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                        } else {
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                            clearTimeout(race);
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                            res(datum.d);
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                            ws.removeEventListener('message', handler);
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                        }
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                    }
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                }
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            }
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        }
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        // construct the message string
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        const queryString = requestData.query || ''
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        const bodyString = JSON.stringify(requestData.body || '')
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        const messageString = `${requestData.endpoint}\n${i}\n${queryString}\n${bodyString}`;
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        ws.addEventListener('message', handler);
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        ws.send(messageString);
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    });
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}

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let lastMessageTime = new Date().getTime();
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ws.onmessage = async function(event) {
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    const timestamp = new Date().getTime();
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    if(timestamp - lastMessageTime > 15000) {
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        // connection has been idle for 15 seconds, reconnect
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        await reconnect();
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    }
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    lastMessageTime = timestamp;
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}