let num_days = cmd_read()

let counter = 0
let current_date = new Date(process.argv[2])



while (counter < num_days) {
    // date format conversion used for query string parameter in api call (yyyymmdd)
    Date.prototype.yyyymmdd = function() {
        var mm = this.getMonth() + 1; // getMonth() is zero-based
        var dd = this.getDate();

        return [this.getFullYear(),
                (mm>9 ? '' : '0') + mm,
                (dd>9 ? '' : '0') + dd
               ].join('');
    };

        // query string necessary in proper format for API call
    querystring = current_date.yyyymmdd();
    console.log(`Fetching data for ${current_date}`)
    api_call(querystring, function(response) {
        console.log(`Data Found: Decompressing zip file...${current_date}`)
        getGzipped(response, function(err, data) {

            const fs = require('fs')
            fs.writeFile("input.txt", data, function(err) {
                if (err) {
                    return console.log(err);
                }
                console.log(`Parsing through Speedcurve data for ${current_date}`)
                text_parser("input.txt", current_date, counter)
                console.log(counter)
            })
        });

    })

    current_date.setDate(current_date.getDate() + 1)
    counter ++
}


// function parses through raw data for given date and only pulls out Custom Vars via regex
function text_parser(input_file, current_date, day_num) {

    var fs = require('fs');

    var file = fs.readFile(input_file, 'utf8', function(err, doc) {
        // regex pattern to find custom data
        var invoca = doc.match(/invocaPhoneNumber\|([^,]*)/g);
        var alliance = doc.match(/allianceId\|([^,]*)/g);
        var ehealth = doc.match(/eHealthPhone\|([^,]*)/g);
        var fs1 = require('fs');
        console.log('Generating data to report file - output.csv')
        if (day_num == 1) {
            const writeStream = fs1.createWriteStream('output.csv');
            writeStream.write(`Alliance ID, Invoca Number, eHealth Number, Date\n`);
            alliance.forEach(value => writeStream.write(`${value.slice(11)}, ${invoca[alliance.indexOf(value)].slice(18)}, ${ehealth[alliance.indexOf(value)].slice(13)}, ${current_date}\n`));

        }
        // else condition simply adds onto existing output report file
        else {
            alliance.forEach(value => fs.appendFile("output.csv",`${value.slice(11)}, ${invoca[alliance.indexOf(value)].slice(18)}, ${ehealth[alliance.indexOf(value)].slice(13)}, ${current_date}\n`));

        }

    });
}


function api_call(querystring, callback) {
    var request = require("request");

    var options = { method: 'GET',
        url: 'https://api.speedcurve.com/v1/lux/export',
        qs: { date:   querystring },
        headers:
            {Connection: 'keep-alive',

            Host: 'api.speedcurve.com',
            'Postman-Token': '9058574c-529e-40ec-9781-0fbfa6720472',
            'Cache-Control': 'no-cache',
            Accept: '*/*',
            'User-Agent': 'PostmanRuntime/7.15.2',


            Authorization: 'Basic N3J0cGkwNHo4OXkybW14ajBsY2FhcWt5cjE0bzFzOng='
        }
    };

    process.env["NODE_TLS_REJECT_UNAUTHORIZED"] = 0;

    request(options, function (error, response, body) {
        if (error) throw new Error(error);

        const regex = /(?<=:")(.*)(?="})/gm;
        let m;

        while ((m = regex.exec(body)) !== null) {
        // This is necessary to avoid infinite loops with zero-width matches
            if (m.index === regex.lastIndex) {
                regex.lastIndex++;
            }
            var download_link = m[0]
            return callback(download_link);
        }

    });

}

function getGzipped(url, callback) {
    // buffer to contain streamed decompression
    var https = require("https"),
    zlib = require("zlib");
    var buffer = [];

    https.get(url, function(res) {
        // pipe the response into the gunzip to decompress
        var gunzip = zlib.createGunzip();
        res.pipe(gunzip);

        gunzip.on('data', function(data) {
         // decompression chunk ready, add it to the buffer
            buffer.push(data.toString())

        }).on("end", function() {
         // response and decompression complete, join the buffer and return
         callback(null, buffer.join(""));

        }).on("error", function(e) {
         callback(e);
        })
    }).on('error', function(e) {
     callback(e)
    });
}



// function sees which date(s) user wants to access and acts on it
function cmd_read() {
    if (process.argv.length < 3) {
        console.log('invalid input')
        process.exit(0)

    }
    if (process.argv.length == 3) { // only one date provided to search
        return 1

    }
    if (process.argv.length == 4) { // find date difference to extract data
        var start = process.argv[2].split('/')
        var end = process.argv[3].split('/')
        var startDate = new Date(start[2], start[0]-1, start[1])
        var endDate = new Date(end[2], end[0]-1, end[1])
        daysbetween = 1 + Math.round((endDate-startDate)/(1000*60*60*24))
        return daysbetween
    }

}