Clean up gas chart code.

3 files changed, 373 insertions, 362 deletions

diff --git a/ui/app/components/gas-customization/gas-modal-page-container/gas-modal-page-container.container.js b/ui/app/components/gas-customization/gas-modal-page-container/gas-modal-page-container.container.js
index 3a62d21cc..67c1ff2e3 100644
--- a/ui/app/components/gas-customization/gas-modal-page-container/gas-modal-page-container.container.js
+++ b/ui/app/components/gas-customization/gas-modal-page-container/gas-modal-page-container.container.js
@@ -69,6 +69,10 @@ const mapStateToProps = state => {
 
   const customGasPrice = calcCustomGasPrice(customModalGasPriceInHex)
 
+  const priceAndTimeEstimates = state.gas.priceAndTimeEstimates
+  const gasPrices = priceAndTimeEstimates.map(({ gasprice }) => gasprice)
+  const estimatedTimes = priceAndTimeEstimates.map(({ expectedTime }) => expectedTime)
+
   return {
     hideBasic,
     isConfirm: isConfirm(state),
@@ -77,7 +81,7 @@ const mapStateToProps = state => {
     customGasPrice,
     customGasLimit: calcCustomGasLimit(customModalGasLimitInHex),
     newTotalFiat,
-    currentTimeEstimate: getRenderableTimeEstimate(customGasPrice, state.gas.priceAndTimeEstimates),
+    currentTimeEstimate: getRenderableTimeEstimate(customGasPrice, priceAndTimeEstimates),
     gasPriceButtonGroupProps: {
       buttonDataLoading,
       defaultActiveButtonIndex: getDefaultActiveButtonIndex(gasButtonInfo, customModalGasPriceInHex),
@@ -85,7 +89,10 @@ const mapStateToProps = state => {
     },
     gasChartProps: {
       currentPrice: customGasPrice,
-      priceAndTimeEstimates: state.gas.priceAndTimeEstimates,
+      gasPrices,
+      estimatedTimes,
+      gasPricesMax: gasPrices[gasPrices.length - 1] + 1,
+      estimatedTimesMax: estimatedTimes[0],
     },
     infoRowProps: {
       originalTotalFiat: addHexWEIsToRenderableFiat(value, gasTotal, currentCurrency, conversionRate),
diff --git a/ui/app/components/gas-customization/gas-price-chart/gas-price-chart.component.js b/ui/app/components/gas-customization/gas-price-chart/gas-price-chart.component.js
index 69bbd12f6..69f8b3a91 100644
--- a/ui/app/components/gas-customization/gas-price-chart/gas-price-chart.component.js
+++ b/ui/app/components/gas-customization/gas-price-chart/gas-price-chart.component.js
@@ -2,75 +2,18 @@ import React, { Component } from 'react'
 import PropTypes from 'prop-types'
 import * as d3 from 'd3'
 import c3 from 'c3'
-
-function setTickPosition (axis, n, newPosition, secondNewPosition) {
-  const positionToShift = axis === 'y' ? 'x' : 'y'
-  const secondPositionToShift = axis === 'y' ? 'y' : 'x'
-  d3.select('#chart')
-    .select(`.c3-axis-${axis}`)
-    .selectAll('.tick')
-    .filter((d, i) => i === n)
-    .select('text')
-    .attr(positionToShift, 0)
-    .select('tspan')
-    .attr(positionToShift, newPosition)
-    .attr(secondPositionToShift, secondNewPosition || 0)
-    .style('visibility', 'visible')
-}
-
-function appendOrUpdateCircle ({ circle, data, itemIndex, cx, cy, cssId, appendOnly }) {
-  if (appendOnly || circle.empty()) {
-    circle.data([data])
-      .enter().append('circle')
-      .attr('class', () => this.generateClass('c3-selected-circle', itemIndex))
-      .attr('id', cssId)
-      .attr('cx', cx)
-      .attr('cy', cy)
-      .attr('stroke', () => this.color(data))
-      .attr('r', 6)
-  } else {
-    circle.data([data])
-      .attr('cx', cx)
-      .attr('cy', cy)
-  }
-}
-
-function setSelectedCircle ({ chart, gasPrices, currentPrice, chartXStart, chartWidth }) {
-  const numberOfValues = chart.internal.data.xs.data1.length
-  const closestLowerValueIndex = gasPrices.findIndex((e, i, a) => {
-    return e <= currentPrice && a[i + 1] >= currentPrice
-  })
-  const closestHigherValueIndex = gasPrices.findIndex((e, i, a) => {
-    return e > currentPrice
-  })
-  const closestHigherValue = gasPrices[closestHigherValueIndex]
-  const closestLowerValue = gasPrices[closestLowerValueIndex]
-
-  if (closestHigherValue && closestLowerValue) {
-    const closestLowerCircle = d3.select(`.c3-circle-${closestLowerValueIndex}`)
-    const closestHigherCircle = d3.select(`.c3-circle-${closestHigherValueIndex}`)
-    const { x: lowerX, y: lowerY } = closestLowerCircle.node().getBoundingClientRect()
-    const { x: higherX, y: higherY } = closestHigherCircle.node().getBoundingClientRect()
-    const currentX = lowerX + (higherX - lowerX) * (currentPrice - closestLowerValue) / (closestHigherValue - closestLowerValue)
-    const slope = (higherY - lowerY) / (higherX - lowerX)
-    const newTimeEstimate = -1 * (slope * (higherX - currentX) - higherY)
-    chart.internal.selectPointB({
-      x: currentX,
-      value: newTimeEstimate,
-      id: 'data1',
-      index: numberOfValues,
-      name: 'data1',
-    }, numberOfValues)
-  } else {
-    const setCircle = d3.select('#set-circle')
-    if (!setCircle.empty()) {
-      setCircle.remove()
-    }
-    d3.select('.c3-tooltip-container').style('display', 'none !important')
-    chart.internal.hideXGridFocus()
-    return
-  }
-}
+import {
+  appendOrUpdateCircle,
+  generateChart,
+  generateDataUIObj,
+  getAdjacentGasPrices,
+  getCoordinateData,
+  getNewXandTimeEstimate,
+  handleChartUpdate,
+  hideDataUI,
+  setSelectedCircle,
+  setTickPosition,
+} from './gas-price-chart.utils.js'
 
 export default class GasPriceChart extends Component {
   static contextTypes = {
@@ -78,225 +21,23 @@ export default class GasPriceChart extends Component {
   }
 
   static propTypes = {
-    priceAndTimeEstimates: PropTypes.array,
+    gasPrices: PropTypes.array,
+    estimatedTimes: PropTypes.array,
+    gasPricesMax: PropTypes.number,
+    estimatedTimesMax: PropTypes.number,
     currentPrice: PropTypes.number,
     updateCustomGasPrice: PropTypes.func,
   }
 
-  renderChart (currentPrice, priceAndTimeEstimates, updateCustomGasPrice) {
-    const gasPrices = priceAndTimeEstimates.map(({ gasprice }) => gasprice)
-    const gasPricesMax = gasPrices[gasPrices.length - 1] + 1
-    const estimatedTimes = priceAndTimeEstimates.map(({ expectedTime }) => expectedTime)
-
-    const estimatedTimesMax = estimatedTimes[0]
-    const chart = c3.generate({
-      size: {
-        height: 165,
-      },
-      transition: {
-        duration: 0,
-      },
-      padding: {left: 20, right: 15, top: 6, bottom: 10},
-      data: {
-          x: 'x',
-          columns: [
-              ['x', ...gasPrices],
-              ['data1', ...estimatedTimes],
-          ],
-          types: {
-            data1: 'area',
-          },
-          selection: {
-            enabled: false,
-          },
-      },
-      color: {
-        data1: '#259de5',
-      },
-      axis: {
-        x: {
-          min: gasPrices[0],
-          max: gasPricesMax,
-          tick: {
-            values: [Math.floor(gasPrices[0]), Math.ceil(gasPricesMax)],
-            outer: false,
-            format: function (val) { return val + ' GWEI' },
-          },
-          padding: {left: gasPricesMax / 50, right: gasPricesMax / 50},
-          label: {
-            text: 'Gas Price ($)',
-            position: 'outer-center',
-          },
-        },
-        y: {
-          padding: {top: 7, bottom: 7},
-          tick: {
-            values: [Math.floor(estimatedTimesMax * 0.05), Math.ceil(estimatedTimesMax * 0.97)],
-            outer: false,
-          },
-          label: {
-            text: 'Confirmation time (sec)',
-            position: 'outer-middle',
-          },
-          min: 0,
-        },
-      },
-      legend: {
-          show: false,
-      },
-      grid: {
-          x: {},
-          lines: {
-            front: false,
-          },
-      },
-      point: {
-        focus: {
-          expand: {
-            enabled: false,
-            r: 3.5,
-          },
-        },
-      },
-      tooltip: {
-        format: {
-          title: (v) => v.toPrecision(4),
-        },
-        contents: function (d, defaultTitleFormat, defaultValueFormat, color) {
-          const config = this.config
-          const titleFormat = config.tooltip_format_title || defaultTitleFormat
-          let text
-          let title
-          d.forEach(el => {
-            if (el && (el.value || el.value === 0) && !text) {
-              title = titleFormat ? titleFormat(el.x) : el.x
-              text = "<table class='" + 'custom-tooltip' + "'>" + (title || title === 0 ? "<tr><th colspan='2'>" + title + '</th></tr>' : '')
-            }
-          })
-          return text + '</table>' + "<div class='tooltip-arrow'></div>"
-        },
-        position: function (data, width, height, element) {
-          const overlayedCircle = d3.select('#overlayed-circle')
-          if (overlayedCircle.empty()) {
-            return { top: -100, left: -100 }
-          }
-
-          const { x: circleX, y: circleY, width: circleWidth } = overlayedCircle.node().getBoundingClientRect()
-          const { x: chartXStart, y: chartYStart } = d3.select('.c3-chart').node().getBoundingClientRect()
-
-          // TODO: Confirm the below constants work with all data sets and screen sizes
-          // TODO: simplify l149-l159
-          let y = circleY - chartYStart - 19
-          if (circleY - circleWidth < chartYStart + 5) {
-            y = y + circleWidth + 38
-            d3.select('.tooltip-arrow').style('margin-top', '-16px')
-          } else {
-            d3.select('.tooltip-arrow').style('margin-top', '4px')
-          }
-          return {
-            top: y,
-            left: circleX - chartXStart + circleWidth - (gasPricesMax / 50),
-          }
-        },
-        show: true,
-      },
-    })
-
-    chart.internal.selectPoint = function (data, itemIndex = (data.index || 0)) {
-      const { x: circleX, y: circleY, width: circleWidth } = d3.select('#overlayed-circle')
-        .node()
-        .getBoundingClientRect()
-      const { x: chartXStart, y: chartYStart } = d3.select('.c3-areas-data1')
-        .node()
-        .getBoundingClientRect()
-
-      d3.select('#set-circle').remove()
-
-      const circle = this.main
-        .select('.' + 'c3-selected-circles' + this.getTargetSelectorSuffix(data.id))
-        .selectAll('.' + 'c3-selected-circle' + '-' + itemIndex)
-
-      appendOrUpdateCircle.bind(this)({
-        circle,
-        data,
-        itemIndex,
-        cx: () => circleX - chartXStart + circleWidth + 2,
-        cy: () => circleY - chartYStart + circleWidth + 1,
-        cssId: 'set-circle',
-        appendOnly: true,
-      })
-    }
-
-    chart.internal.selectPointB = function (data, itemIndex = (data.index || 0)) {
-      const { x: chartXStart, y: chartYStart } = d3.select('.c3-areas-data1')
-        .node()
-        .getBoundingClientRect()
-
-      d3.select('#set-circle').remove()
-
-      const circle = this.main
-        .select('.' + 'c3-selected-circles' + this.getTargetSelectorSuffix(data.id))
-        .selectAll('.' + 'c3-selected-circle' + '-' + itemIndex)
-
-      appendOrUpdateCircle.bind(this)({
-        circle,
-        data,
-        itemIndex,
-        cx: () => data.x - chartXStart + 11,
-        cy: () => data.value - chartYStart + 10,
-        cssId: 'set-circle',
-        appendOnly: true,
-      })
-    }
-
-    chart.internal.overlayPoint = function (data, itemIndex) {
-        const circle = this.main
-          .select('.' + 'c3-selected-circles' + this.getTargetSelectorSuffix(data.id))
-          .selectAll('.' + 'c3-selected-circle' + '-' + itemIndex)
-
-        appendOrUpdateCircle.bind(this)({
-          circle,
-          data,
-          itemIndex,
-          cx: this.circleX.bind(this),
-          cy: this.circleY.bind(this),
-          cssId: 'overlayed-circle',
-        })
-    }
-
-    chart.internal.setCurrentCircle = function (data, itemIndex) {
-      const circle = this.main
-        .select('.' + 'c3-selected-circles' + this.getTargetSelectorSuffix(data.id))
-        .selectAll('#current-circle')
-
-      appendOrUpdateCircle.bind(this)({
-        circle,
-        data,
-        itemIndex,
-        cx: this.circleX.bind(this),
-        cy: this.circleY.bind(this),
-        cssId: 'current-circle',
-      })
-    }
-
-    chart.internal.showTooltip = function (selectedData, element) {
-      const $$ = this
-      const config = $$.config
-      const forArc = $$.hasArcType()
-      const dataToShow = selectedData.filter((d) => d && (d.value || d.value === 0))
-      const positionFunction = config.tooltip_position || chart.internal.prototype.tooltipPosition
-      if (dataToShow.length === 0 || !config.tooltip_show) {
-        return
-      }
-      $$.tooltip.html(config.tooltip_contents.call($$, selectedData, $$.axis.getXAxisTickFormat(), $$.getYFormat(forArc), $$.color)).style('display', 'flex')
-
-      // Get tooltip dimensions
-      const tWidth = $$.tooltip.property('offsetWidth')
-      const tHeight = $$.tooltip.property('offsetHeight')
-      const position = positionFunction.call(this, dataToShow, tWidth, tHeight, element)
-      // Set tooltip
-      $$.tooltip.style('top', position.top + 'px').style('left', position.left + 'px')
-    }
+  renderChart ({
+    currentPrice,
+    gasPrices,
+    estimatedTimes,
+    gasPricesMax,
+    estimatedTimesMax,
+    updateCustomGasPrice,
+  }) {
+    const chart = generateChart(gasPrices, estimatedTimes, gasPricesMax, estimatedTimesMax) 
 
     setTimeout(function () {
       setTickPosition('y', 0, -5, 8)
@@ -310,84 +51,42 @@ export default class GasPriceChart extends Component {
       d3.select('.c3-xgrid-focus line').attr('y2', 98)
 
       d3.select('.c3-chart').on('mouseout', () => {
-        const overLayedCircle = d3.select('#overlayed-circle')
-        if (!overLayedCircle.empty()) {
-          overLayedCircle.remove()
-        }
-        d3.select('.c3-tooltip-container').style('display', 'none !important')
+        hideDataUI(chart, '#overlayed-circle')
       })
 
-      const chartRect = d3.select('.c3-areas-data1')
-      const { x: chartXStart, width: chartWidth } = chartRect.node().getBoundingClientRect()
-
       d3.select('.c3-chart').on('click', () => {
-        const overlayedCircle = d3.select('#overlayed-circle')
-        const numberOfValues = chart.internal.data.xs.data1.length
-        const { x: circleX, y: circleY } = overlayedCircle.node().getBoundingClientRect()
-        const { x: xData } = overlayedCircle.datum()
-        chart.internal.selectPoint({
-          x: circleX - chartXStart,
-          value: circleY - 1.5,
-          id: 'data1',
-          index: numberOfValues,
-          name: 'data1',
-        }, numberOfValues)
-        updateCustomGasPrice(xData)
+        const { x: newGasPrice } = d3.select('#overlayed-circle').datum()
+        updateCustomGasPrice(newGasPrice)
       })
 
-      setSelectedCircle({ chart, gasPrices, currentPrice, chartXStart, chartWidth })
+      const { x: chartXStart, width: chartWidth } = getCoordinateData('.c3-areas-data1')
 
-      d3.select('.c3-chart').on('mousemove', function () {
-        const chartMouseXPos = d3.event.clientX - chartXStart
-        const posPercentile = chartMouseXPos / chartWidth
+      handleChartUpdate ({
+        chart,
+        gasPrices,
+        newPrice: currentPrice,
+        cssId: '#set-circle',
+      })
 
-        const currentPosValue = (gasPrices[gasPrices.length - 1] - gasPrices[0]) * posPercentile + gasPrices[0]
-        const closestLowerValueIndex = gasPrices.findIndex((e, i, a) => {
-          return e <= currentPosValue && a[i + 1] >= currentPosValue
+      d3.select('.c3-chart').on('mousemove', function () {
+        const { currentPosValue, newTimeEstimate } = getNewXandTimeEstimate({
+          xMousePos: d3.event.clientX,
+          chartXStart,
+          chartWidth,
+          gasPrices,
+          estimatedTimes,
         })
-        const closestLowerValue = gasPrices[closestLowerValueIndex]
-        const estimatedClosestLowerTimeEstimate = estimatedTimes[closestLowerValueIndex]
 
-        const closestHigherValueIndex = gasPrices.findIndex((e, i, a) => {
-          return e > currentPosValue
-        })
-        const closestHigherValue = gasPrices[closestHigherValueIndex]
-        if (!closestHigherValue || !closestLowerValue) {
-          const overLayedCircle = d3.select('#overlayed-circle')
-          if (!overLayedCircle.empty()) {
-            overLayedCircle.remove()
-          }
-          d3.select('.c3-tooltip-container').style('display', 'none !important')
-          chart.internal.hideXGridFocus()
-          return
+        if (currentPosValue === null && newTimeEstimate === null) {
+          hideDataUI(chart, '#overlayed-circle')
         }
-        const estimatedClosestHigherTimeEstimate = estimatedTimes[closestHigherValueIndex]
 
-        const slope = (estimatedClosestHigherTimeEstimate - estimatedClosestLowerTimeEstimate) / (closestHigherValue - closestLowerValue)
-        const newTimeEstimate = -1 * (slope * (closestHigherValue - currentPosValue) - estimatedClosestHigherTimeEstimate)
+        const indexOfNewCircle = estimatedTimes.length + 1
+        const dataUIObj = generateDataUIObj(currentPosValue, indexOfNewCircle, newTimeEstimate)
 
-        const newEstimatedTimes = [...estimatedTimes, newTimeEstimate]
-        chart.internal.overlayPoint({
-          x: currentPosValue,
-          value: newTimeEstimate,
-          id: 'data1',
-          index: newEstimatedTimes.length,
-          name: 'data1',
-        }, newEstimatedTimes.length)
-        chart.internal.showTooltip([{
-          x: currentPosValue,
-          value: newTimeEstimate,
-          id: 'data1',
-          index: newEstimatedTimes.length,
-          name: 'data1',
-        }], chartRect._groups[0])
-        chart.internal.showXGridFocus([{
-          x: currentPosValue,
-          value: newTimeEstimate,
-          id: 'data1',
-          index: newEstimatedTimes.length,
-          name: 'data1',
-        }])
+        chart.internal.overlayPoint(dataUIObj, indexOfNewCircle)
+        chart.internal.showTooltip([dataUIObj], d3.select('.c3-areas-data1')._groups[0])
+        chart.internal.showXGridFocus([dataUIObj])
       })
     }, 0)
 
@@ -395,22 +94,20 @@ export default class GasPriceChart extends Component {
   }
 
   componentDidUpdate (prevProps) {
-    if (prevProps.currentPrice !== this.props.currentPrice) {
-      const chartRect = d3.select('.c3-areas-data1')
-      const { x: chartXStart, width: chartWidth } = chartRect.node().getBoundingClientRect()
-      setSelectedCircle({
+    const { gasPrices, currentPrice: newPrice } = this.props
+
+    if (prevProps.currentPrice !== newPrice) {
+      handleChartUpdate ({
         chart: this.chart,
-        currentPrice: this.props.currentPrice,
-        gasPrices: this.props.priceAndTimeEstimates.map(({ gasprice }) => gasprice),
-        chartXStart,
-        chartWidth,
+        gasPrices,
+        newPrice,
+        cssId: '#set-circle',
       })
     }
   }
 
   componentDidMount () {
-    const { currentPrice, priceAndTimeEstimates, updateCustomGasPrice } = this.props
-    this.renderChart(currentPrice, priceAndTimeEstimates, updateCustomGasPrice)
+    this.renderChart(this.props)
   }
 
   render () {
diff --git a/ui/app/components/gas-customization/gas-price-chart/gas-price-chart.utils.js b/ui/app/components/gas-customization/gas-price-chart/gas-price-chart.utils.js
new file mode 100644
index 000000000..43bbfd9ab
--- /dev/null
+++ b/ui/app/components/gas-customization/gas-price-chart/gas-price-chart.utils.js
@@ -0,0 +1,307 @@
+import * as d3 from 'd3'
+import c3 from 'c3'
+
+export function getCoordinateData (selector) {
+   return d3.select(selector).node().getBoundingClientRect()
+}
+
+export function generateDataUIObj (x, index, value) {
+  return {
+    x,
+    value,
+    index,
+    id: 'data1',
+    name: 'data1',
+  }
+}
+
+export function handleChartUpdate ({ chart, gasPrices, newPrice, cssId }) {
+  const {
+    closestLowerValueIndex,
+    closestLowerValue,
+    closestHigherValueIndex,
+    closestHigherValue,
+  } = getAdjacentGasPrices({ gasPrices, priceToPosition: newPrice })
+
+  if (closestLowerValue && closestHigherValue) {
+    setSelectedCircle({
+      chart,
+      newPrice,
+      closestLowerValueIndex,
+      closestLowerValue,
+      closestHigherValueIndex,
+      closestHigherValue,
+    })
+  } else {
+    hideDataUI(chart, cssId)
+  }
+}
+
+export function getAdjacentGasPrices({ gasPrices, priceToPosition }) {
+  const closestLowerValueIndex = gasPrices.findIndex((e, i, a) => e <= priceToPosition && a[i + 1] >= priceToPosition)
+  const closestHigherValueIndex = gasPrices.findIndex((e, i, a) => e > priceToPosition)
+  return {
+    closestLowerValueIndex,
+    closestHigherValueIndex,
+    closestHigherValue: gasPrices[closestHigherValueIndex],
+    closestLowerValue: gasPrices[closestLowerValueIndex],
+  }
+}
+
+export function extrapolateY ({ higherY, lowerY, higherX, lowerX, xForExtrapolation }) {
+  const slope = (higherY - lowerY) / (higherX - lowerX)
+  const newTimeEstimate = -1 * (slope * (higherX - xForExtrapolation) - higherY)
+
+  return newTimeEstimate
+}
+
+
+export function getNewXandTimeEstimate ({ xMousePos, chartXStart, chartWidth, gasPrices, estimatedTimes }) {
+  const chartMouseXPos = xMousePos - chartXStart
+  const posPercentile = chartMouseXPos / chartWidth
+
+  const currentPosValue = (gasPrices[gasPrices.length - 1] - gasPrices[0]) * posPercentile + gasPrices[0]
+
+  const {
+    closestLowerValueIndex,
+    closestLowerValue,
+    closestHigherValueIndex,
+    closestHigherValue,
+  } = getAdjacentGasPrices({ gasPrices, priceToPosition: currentPosValue })
+
+  return  !closestHigherValue || !closestLowerValue
+    ? {
+      currentPosValue: null,
+      newTimeEstimate: null,
+    }
+    : {
+      currentPosValue,
+      newTimeEstimate: extrapolateY ({
+        higherY: estimatedTimes[closestHigherValueIndex],
+        lowerY: estimatedTimes[closestLowerValueIndex],
+        higherX: closestHigherValue,
+        lowerX: closestLowerValue,
+        xForExtrapolation: currentPosValue,
+      }),
+    }
+}
+
+export function hideDataUI (chart, dataNodeId) {
+  const overLayedCircle = d3.select(dataNodeId)
+  if (!overLayedCircle.empty()) {
+    overLayedCircle.remove()
+  }
+  d3.select('.c3-tooltip-container').style('display', 'none !important')
+  chart.internal.hideXGridFocus()
+}
+
+export function setTickPosition (axis, n, newPosition, secondNewPosition) {
+  const positionToShift = axis === 'y' ? 'x' : 'y'
+  const secondPositionToShift = axis === 'y' ? 'y' : 'x'
+  d3.select('#chart')
+    .select(`.c3-axis-${axis}`)
+    .selectAll('.tick')
+    .filter((d, i) => i === n)
+    .select('text')
+    .attr(positionToShift, 0)
+    .select('tspan')
+    .attr(positionToShift, newPosition)
+    .attr(secondPositionToShift, secondNewPosition || 0)
+    .style('visibility', 'visible')
+}
+
+export function appendOrUpdateCircle ({ data, itemIndex, cx, cy, cssId, appendOnly }) {
+  const circle = this.main
+    .select('.' + 'c3-selected-circles' + this.getTargetSelectorSuffix(data.id))
+    .selectAll('.' + 'c3-selected-circle' + '-' + itemIndex)
+
+  if (appendOnly || circle.empty()) {
+    circle.data([data])
+      .enter().append('circle')
+      .attr('class', () => this.generateClass('c3-selected-circle', itemIndex))
+      .attr('id', cssId)
+      .attr('cx', cx)
+      .attr('cy', cy)
+      .attr('stroke', () => this.color(data))
+      .attr('r', 6)
+  } else {
+    circle.data([data])
+      .attr('cx', cx)
+      .attr('cy', cy)
+  }
+}
+
+export function setSelectedCircle ({
+  chart,
+  newPrice,
+  closestLowerValueIndex,
+  closestLowerValue,
+  closestHigherValueIndex,
+  closestHigherValue,
+}) {
+  const numberOfValues = chart.internal.data.xs.data1.length
+  const { x: lowerX, y: lowerY } = getCoordinateData(`.c3-circle-${closestLowerValueIndex}`)
+  const { x: higherX, y: higherY } = getCoordinateData(`.c3-circle-${closestHigherValueIndex}`)
+
+  const currentX = lowerX + (higherX - lowerX) * (newPrice - closestLowerValue) / (closestHigherValue - closestLowerValue)
+  const newTimeEstimate = extrapolateY ({ higherY, lowerY, higherX, lowerX, xForExtrapolation: currentX })
+
+  chart.internal.selectPoint(
+    generateDataUIObj(currentX, numberOfValues, newTimeEstimate),
+    numberOfValues
+  )
+}
+
+
+export function generateChart (gasPrices, estimatedTimes, gasPricesMax, estimatedTimesMax) {
+  const chart = c3.generate({
+    size: {
+      height: 165,
+    },
+    transition: {
+      duration: 0,
+    },
+    padding: {left: 20, right: 15, top: 6, bottom: 10},
+    data: {
+        x: 'x',
+        columns: [
+            ['x', ...gasPrices],
+            ['data1', ...estimatedTimes],
+        ],
+        types: {
+          data1: 'area',
+        },
+        selection: {
+          enabled: false,
+        },
+    },
+    color: {
+      data1: '#259de5',
+    },
+    axis: {
+      x: {
+        min: gasPrices[0],
+        max: gasPricesMax,
+        tick: {
+          values: [Math.floor(gasPrices[0]), Math.ceil(gasPricesMax)],
+          outer: false,
+          format: function (val) { return val + ' GWEI' },
+        },
+        padding: {left: gasPricesMax / 50, right: gasPricesMax / 50},
+        label: {
+          text: 'Gas Price ($)',
+          position: 'outer-center',
+        },
+      },
+      y: {
+        padding: {top: 7, bottom: 7},
+        tick: {
+          values: [Math.floor(estimatedTimesMax * 0.05), Math.ceil(estimatedTimesMax * 0.97)],
+          outer: false,
+        },
+        label: {
+          text: 'Confirmation time (sec)',
+          position: 'outer-middle',
+        },
+        min: 0,
+      },
+    },
+    legend: {
+        show: false,
+    },
+    grid: {
+        x: {},
+        lines: {
+          front: false,
+        },
+    },
+    point: {
+      focus: {
+        expand: {
+          enabled: false,
+          r: 3.5,
+        },
+      },
+    },
+    tooltip: {
+      format: {
+        title: (v) => v.toPrecision(4),
+      },
+      contents: function (d) {
+        const titleFormat = this.config.tooltip_format_title
+        let text
+        d.forEach(el => {
+          if (el && (el.value || el.value === 0) && !text) {
+            text = "<table class='" + 'custom-tooltip' + "'>" + "<tr><th colspan='2'>" + titleFormat(el.x) + '</th></tr>'
+          }
+        })
+        return text + '</table>' + "<div class='tooltip-arrow'></div>"
+      },
+      position: function (data) {
+        if (d3.select('#overlayed-circle').empty()) {
+          return { top: -100, left: -100 }
+        }
+
+        const { x: circleX, y: circleY, width: circleWidth } = getCoordinateData('#overlayed-circle')
+        const { x: chartXStart, y: chartYStart } = getCoordinateData('.c3-chart')
+
+        // TODO: Confirm the below constants work with all data sets and screen sizes
+        const flipTooltip = circleY - circleWidth < chartYStart + 5
+
+        d3
+        .select('.tooltip-arrow')
+        .style('margin-top', flipTooltip ? '-16px' : '4px')
+
+        return {
+          top: circleY - chartYStart - 19 + (flipTooltip ? circleWidth + 38 : 0),
+          left: circleX - chartXStart + circleWidth - (gasPricesMax / 50),
+        }
+      },
+      show: true,
+    },
+  })
+
+  chart.internal.selectPoint = function (data, itemIndex = (data.index || 0)) {
+    const { x: chartXStart, y: chartYStart } = getCoordinateData('.c3-areas-data1')
+
+    d3.select('#set-circle').remove()
+
+    appendOrUpdateCircle.bind(this)({
+      data,
+      itemIndex,
+      cx: () => data.x - chartXStart + 11,
+      cy: () => data.value - chartYStart + 10,
+      cssId: 'set-circle',
+      appendOnly: true,
+    })
+  }
+
+  chart.internal.overlayPoint = function (data, itemIndex) {
+    appendOrUpdateCircle.bind(this)({
+      data,
+      itemIndex,
+      cx: this.circleX.bind(this),
+      cy: this.circleY.bind(this),
+      cssId: 'overlayed-circle',
+    })
+  }
+
+  chart.internal.showTooltip = function (selectedData, element) {
+    const dataToShow = selectedData.filter((d) => d && (d.value || d.value === 0))
+
+    if (dataToShow.length) {
+      this.tooltip.html(
+        this.config.tooltip_contents.call(this, selectedData, this.axis.getXAxisTickFormat(), this.getYFormat(), this.color)
+      ).style('display', 'flex')
+
+      // Get tooltip dimensions
+      const tWidth = this.tooltip.property('offsetWidth')
+      const tHeight = this.tooltip.property('offsetHeight')
+      const position = this.config.tooltip_position.call(this, dataToShow, tWidth, tHeight, element)
+      // Set tooltip
+      this.tooltip.style('top', position.top + 'px').style('left', position.left + 'px')
+    }
+  }
+
+  return chart
+}