Market Bias

// This source code is subject to the terms of the Mozilla Public License 2.0 at https://mozilla.org/MPL/2.0/
// © Professeur_X
//Ported from Tradingview to Trend Spider by colinweber@gmail.com

let tinycolor = library("tinycolor2");

describe_indicator('Market Bias');

// Inputs
const ha_len = input.number('Period', 20);
const ha_len2 = input.number('Smoothing', 7);
const col_bull = input.color('Color: Bullish', 'lime');
const col_bear = input.color('Bearish', 'red');
const osc_len = input.number("Oscillator Period", 7);
const showValues = input.boolean("Show Values", false);

//Using built in open,close, high, low variables 
//These change depending on what chart type the users chooses, 
//will only make sense if user has chart type set to OHLC type
//Backtest results won't make sense if chart type is Heikin-Ashi

// Smoothen the OHLC values 
const o = ema(open, ha_len);
const c = ema(close, ha_len);
const h = ema(high, ha_len);
const l = ema(low, ha_len);

// Initialize arrays to store Heikin-Ashi values
let haopen = [];
let hahigh = [];
let halow = [];
let haclose = [];

// Initialize the first Heikin-Ashi OHLC values
let aOpen = o.length > 0 ? o[0] : 0;
let aClose = c.length > 0 ? c[0] : 0;

for (let i = 0; i < o.length; i++) {
    const hopen = o[i];
    const hhigh = h[i];
    const hlow = l[i];
    const hclose = c[i];

    const haCloseCurrent = (hopen + hhigh + hlow + hclose) / 4;
    const haOpenCurrent = (aOpen + aClose) / 2;
    const haHighCurrent = Math.max(hhigh, haOpenCurrent, haCloseCurrent);
    const haLowCurrent = Math.min(hlow, haOpenCurrent, haCloseCurrent);

	if(hopen === null || hhigh ===null || hlow === null || hclose == null)
	{
		haopen.push(null);
	    hahigh.push(null);
	    halow.push(null);
	    haclose.push(null);
	}
	else{
	    haopen.push(haOpenCurrent);
	    hahigh.push(haHighCurrent);
	    halow.push(haLowCurrent);
	    haclose.push(haCloseCurrent);
	}

    // Update for the next iteration
    aOpen = haOpenCurrent;
    aClose = haCloseCurrent;
}

// Smoothen the Heiken Ashi Candles
let o2 = ema(haopen, ha_len2)
let c2 = ema(haclose, ha_len2)
let h2 = ema(hahigh, ha_len2)
let l2 = ema(halow, ha_len2)

o2 = shift(o2,-1);
c2 = shift(c2,-2);

//debugger;
// Oscillator
let osc_bias = c2.map((value, index) => 100 * (value - o2[index]));
let osc_smooth = ema(osc_bias, osc_len)

const doubleBullAreaTop = series_of(null);
const doubleBullAreaBottom = series_of(null);
const bullAreaTop = series_of(null);
const bullAreaBottom = series_of(null);
const doubleBearAreaTop = series_of(null);
const doubleBearAreaBottom = series_of(null);
const bearAreaTop = series_of(null);
const bearAreaBottom = series_of(null);

//debugger;
const sigcolor = for_every(osc_bias, osc_smooth, (bias, smooth ,prevValue, index) => {
    if (bias > 0 && bias >= smooth){
		doubleBullAreaTop[index] = h2[index];
		doubleBullAreaBottom[index] = l2[index];
		return tinycolor(col_bull).setAlpha(0.95).toRgbString();
	}
    if (bias > 0 && bias < smooth) {
		bullAreaTop[index] = h2[index];
		bullAreaBottom[index] = l2[index];
		return tinycolor(col_bull).setAlpha(0.15).toRgbString();
	}
    if (bias < 0 && bias <= smooth) {
		doubleBearAreaTop[index] = h2[index];
		doubleBearAreaBottom[index] = l2[index];
		return tinycolor(col_bear).setAlpha(0.95).toRgbString();
	}
    if (bias < 0 && bias > smooth) {
		bearAreaTop[index] = h2[index];
		bearAreaBottom[index] = l2[index];
		return tinycolor(col_bear).setAlpha(0.15).toRgbString();
	}
    return null;
});

//set first 25 values to null.
for (let y = 0; y < 25; y++) {
	h2[y] = null;
	l2[y] = null;
}


//PLOTS
let p_h = paint(h2, "Bias High", sigcolor,'line',1, false, false, true);
let p_l = paint(l2, "Bias Low", sigcolor,'line',1, false, false, true);

if(showValues)
{
for (let i = 0; i < h2.length; i++) {
    paint_label_at_line(p_h, i, ''+(Math.round(h2[i] * 10) / 10));
	paint_label_at_line(p_l, i, ''+(Math.round(l2[i] * 10) / 10));
}
}


//Given a sigcolor will return the array it corresponds to
const getBottomArrayByColor = (color) => {
	if(color === null) return null;
	if (color == tinycolor(col_bull).setAlpha(0.95).toRgbString())
		return doubleBullAreaBottom
	if (color == tinycolor(col_bull).setAlpha(0.15).toRgbString())
		return bullAreaBottom
	if (color == tinycolor(col_bear).setAlpha(0.95).toRgbString())
		return doubleBearAreaBottom
	if (color == tinycolor(col_bear).setAlpha(0.15).toRgbString())
		return bearAreaBottom
}

const getTopArrayByColor = (color) => {
	if(color === null) return null;
	if (color == tinycolor(col_bull).setAlpha(0.95).toRgbString())
		return doubleBullAreaTop
	if (color == tinycolor(col_bull).setAlpha(0.15).toRgbString())
		return bullAreaTop
	if (color == tinycolor(col_bear).setAlpha(0.95).toRgbString())
		return doubleBearAreaTop
	if (color == tinycolor(col_bear).setAlpha(0.15).toRgbString())
		return bearAreaTop
}

//Fills in blank spaces in the background color
function fillTopArray(arr)  {
// Create a copy of the original array
  let newArr = [...arr];
  for (let i = 1; i < arr.length; i++) {
    if (arr[i] === null && arr[i-1] !== null) {
	  let nextArray = getTopArrayByColor(sigcolor[i]);
      if(nextArray === null) continue;
      newArr[i] = nextArray[i];
    }
  }
  return newArr;
}

function fillBottomArray(arr)  {
// Create a copy of the original array
  let newArr = [...arr];
  for (let i = 1; i < arr.length; i++) {
    if (arr[i] === null && arr[i-1] !== null) {
	  let nextArray = getBottomArrayByColor(sigcolor[i]);
      if(nextArray === null) continue;
      newArr[i] = nextArray[i];
    }
  }
  return newArr;
}

fill(
	paint(fillTopArray(doubleBullAreaTop ), "", "random color", "line", 1, true, true),
	paint(fillBottomArray(doubleBullAreaBottom), "", "random color", "line", 1, true, true),
	col_bull, 0.95,""
);

fill(
	paint(fillTopArray(bullAreaTop), "", "random color", "line", 1, true, true),
	paint(fillBottomArray(bullAreaBottom), "", "random color", "line", 1, true, true),
	col_bull ,0.15,""
);

fill(
	paint(fillTopArray(doubleBearAreaTop), "", "random color", "line", 1, true, true),
	paint(fillBottomArray(doubleBearAreaBottom), "", "random color", "line", 1, true, true),
	col_bear, 0.95,""
);

fill(
	paint(fillTopArray(bearAreaTop,sigcolor), "", "random color", "line", 1, true, true),
	paint(fillBottomArray(bearAreaBottom,sigcolor), "", "random color", "line", 1, true, true),
	col_bear, 0.15, ""
);