// 


// data will be sorted by earliest to latest

const rawAudits = rawJson.audits;
const latest = rawAudits.reverse();

const sdmAudits = rawAudits.filter( row => row.company === "SDM");

const todayMoment = moment(new Date()); 

// Landing - 4 Dates - a week apart 

const isDaysApart = (row, range) => {
  
  const start = moment(new Date()).subtract(range.start, 'days');
  const end = moment(new Date()).subtract(range.end, 'days');
  const test = moment(row.created_on);
  
  const isBetween = test.isBetween(start, end, 'days');
  //const difference = todayMoment 
  return isBetween;
}

const thisWeekfilter = row => {
  const isBetween = isDaysApart(row, {start: 7, end: 0});
  
  if (row.label === "Landing" && isBetween){
    return row;
  }
}

const lastWeekfilter = row => {
  const isBetween = isDaysApart(row, {start: 14, end: 7});
  
  if (row.label === "Landing" && isBetween){
    return row;
  }
}

const threeWeeksAgofilter = row => {
  const isBetween = isDaysApart(row, {start: 21, end: 14});
  
  if (row.label === "Landing" && isBetween){
    return row;
  }
}

const fourWeeksAgofilter = row => {
  const isBetween = isDaysApart(row, {start: 28, end: 21});
  
  if (row.label === "Landing" && isBetween){
    return row;
  }
}

// currently we can go only go back 3 weeks

const landingMomentsThisWeek = sdmAudits.find(thisWeekfilter);
const landingMomentsLastWeek = sdmAudits.find(lastWeekfilter);
const landingMomentsThreeWeeksAgo = sdmAudits.find(threeWeeksAgofilter);
// const landingMomentsFourWeeksAgo = sdmAudits.find(fourWeeksAgofilter);

console.log("y landingMomentsThreeWeeksAgo: ", landingMomentsThreeWeeksAgo)

function addRow(arrHead, tableId, label, prop) {
  
  const empTab = document.getElementById(tableId);
        
        var rowCnt = empTab.rows.length;        // GET TABLE ROW COUNT.
        var tr = empTab.insertRow(rowCnt);      // TABLE ROW.
        tr = empTab.insertRow(rowCnt);

        for (var c = 0; c < arrHead.length; c++) {
            var td = document.createElement('td');          // TABLE DEFINITION.
            td = tr.insertCell(c);

            // CREATE AND ADD TEXTBOX IN EACH CELL.
            var ele = document.createElement('input');
            ele.setAttribute('type', 'text');
            ele.setAttribute('value', arrHead[c]);

            td.appendChild(ele);
            
        }
    }


// https://stackoverflow.com/questions/6195335/linear-regression-in-javascript

function linearRegression(y,x){
        var lr = {};
        var n = y.length;
        var sum_x = 0;
        var sum_y = 0;
        var sum_xy = 0;
        var sum_xx = 0;
        var sum_yy = 0;

        for (var i = 0; i < y.length; i++) {

            sum_x += x[i];
            sum_y += y[i];
            sum_xy += (x[i]*y[i]);
            sum_xx += (x[i]*x[i]);
            sum_yy += (y[i]*y[i]);
        } 

        lr['slope'] = (n * sum_xy - sum_x * sum_y) / (n*sum_xx - sum_x * sum_x);
        lr['intercept'] = (sum_y - lr.slope * sum_x)/n;
        lr['r2'] = Math.pow((n*sum_xy - sum_x*sum_y)/Math.sqrt((n*sum_xx-sum_x*sum_x)*(n*sum_yy-sum_y*sum_y)),2);

        return lr;
}

function linearRegressionGain(x, y)
{
    var xs = 0;  // sum(x)
    var ys = 0;  // sum(y)
    var xxs = 0; // sum(x*x)
    var xys = 0; // sum(x*y)
    var yys = 0; // sum(y*y)

    var n = 0;
    for (; n < x.length && n < y.length; n++)
    {
        xs += x[n];
        ys += y[n];
        xxs += x[n] * x[n];
        xys += x[n] * y[n];
        yys += y[n] * y[n];
    }

    var div = n * xxs - xs * xs;
    var gain = (n * xys - xs * ys) / div;
    var offset = (ys * xxs - xs * xys) / div;
    var correlation = Math.abs((xys * n - xs * ys) / Math.sqrt((xxs * n - xs * xs) * (yys * n - ys * ys)));

    return { gain: gain, offset: offset, correlation: correlation };
}

const thisWeek = Number(landingMomentsThisWeek.performance_score);
const lastWeek =  Number(landingMomentsLastWeek.performance_score);
const threeWeeksAgo = Number(landingMomentsThreeWeeksAgo.performance_score);

var known_y = [1, 2, 3];
var known_x = [threeWeeksAgo, lastWeek, thisWeek];

var slope = linearRegression(known_y, known_x);
var lr = linearRegressionGain(known_y, known_x);
 
const getTrend = lr => {
  let trend;
  if (lr.gain > 0){
  trend = `Up ${lr.gain.toFixed(1)}`
} else if (lr.gain < 0) {
  trend = `Down ${lr.gain.toFixed(1)}`
} else {
  trend = "No Change"; 
}
  return trend; 
}


const perfArr = [
  landingMomentsThisWeek.label,
  "unavailable",
  String(landingMomentsThreeWeeksAgo.performance_score),
  String(landingMomentsLastWeek.performance_score),
  String(landingMomentsThisWeek.performance_score),
  getTrend(lr)
]

addRow(perfArr, "performanceMonthTable")

const thisWeekInt = Number(landingMomentsThisWeek.time_to_interactive.slice(0,-1));
const lastWeekInt =  Number(landingMomentsLastWeek.time_to_interactive.slice(0,-1));
const threeWeeksAgoInt = Number(landingMomentsThreeWeeksAgo.time_to_interactive.slice(0,-1));

var known_y_int = [1, 2, 3];
var known_x_int = [threeWeeksAgoInt, lastWeekInt, thisWeekInt];
var lr_int = linearRegressionGain(known_y_int, known_x_int);

const interactiveArr = [
  "time to interactive",
  "unavailable",
  String(landingMomentsThreeWeeksAgo.time_to_interactive),
  String(landingMomentsLastWeek.time_to_interactive),
  String(landingMomentsThisWeek.time_to_interactive),
  getTrend(lr_int)
]

const addRows = () => {
 
  const rows = ["time_to_contentful_paint","time_to_meaningful_paint","time_to_interactive"];
  
  rows.forEach( row => {
    
    const thisWInt = Number(landingMomentsThisWeek[row].slice(0,-1));
    const lastWInt =  Number(landingMomentsLastWeek[row].slice(0,-1));
    const threeWInt = Number(landingMomentsThreeWeeksAgo[row].slice(0,-1));

    const known_y_int = [1, 2, 3];
    const known_x_int = [threeWInt, lastWInt, thisWInt];
    const lr_int = linearRegressionGain(known_y_int, known_x_int);
    
    const arr = [
            row.split("_").join(" "),
            "unavailable",
            String(landingMomentsThreeWeeksAgo[row]),
            String(landingMomentsLastWeek[row]),
            String(landingMomentsThisWeek[row]),
            getTrend(lr_int)
	 ]
    
    addRow(arr, "interactiveMonthTable")
    
  })
  
}

addRows()