10 files changed, 475 insertions, 50 deletions

diff --git a/ui/app/components/eth-balance.js b/ui/app/components/eth-balance.js
index 4f538fd31..32ff4efdf 100644
--- a/ui/app/components/eth-balance.js
+++ b/ui/app/components/eth-balance.js
@@ -37,7 +37,17 @@ EthBalanceComponent.prototype.render = function () {
 }
 EthBalanceComponent.prototype.renderBalance = function (value) {
   var props = this.props
-  const { conversionRate, shorten, incoming, currentCurrency } = props
+  const {
+    conversionRate,
+    shorten,
+    incoming,
+    currentCurrency,
+    hideTooltip,
+    styleOveride,
+  } = props
+
+  const { fontSize, color, fontFamily, lineHeight } = styleOveride
+
   if (value === 'None') return value
   if (value === '...') return value
   var balanceObj = generateBalanceObject(value, shorten ? 1 : 3)
@@ -54,36 +64,41 @@ EthBalanceComponent.prototype.renderBalance = function (value) {
   }
 
   var label = balanceObj.label
+  const tooltipProps = hideTooltip ? {} : {
+    position: 'bottom',
+    title: `${ethNumber} ${ethSuffix}`,
+  };
 
   return (
-    h(Tooltip, {
-      position: 'bottom',
-      title: `${ethNumber} ${ethSuffix}`,
-    }, h('div.flex-column', [
-      h('.flex-row', {
-        style: {
-          alignItems: 'flex-end',
-          lineHeight: '13px',
-          fontFamily: 'Montserrat Light',
-          textRendering: 'geometricPrecision',
-        },
-      }, [
-        h('div', {
-          style: {
-            width: '100%',
-            textAlign: 'right',
-          },
-        }, incoming ? `+${balance}` : balance),
-        h('div', {
+    h(hideTooltip ? 'div' : Tooltip,
+      tooltipProps,
+      h('div.flex-column', [
+        h('.flex-row', {
           style: {
-            color: ' #AEAEAE',
-            fontSize: '12px',
-            marginLeft: '5px',
+            alignItems: 'flex-end',
+            lineHeight: lineHeight || '13px',
+            fontFamily: fontFamily || 'Montserrat Light',
+            textRendering: 'geometricPrecision',
           },
-        }, label),
-      ]),
+        }, [
+          h('div', {
+            style: {
+              width: '100%',
+              textAlign: 'right',
+              fontSize: fontSize || 'inherit',
+              color: color || 'inherit',
+            },
+          }, incoming ? `+${balance}` : balance),
+          h('div', {
+            style: {
+              color: color || '#AEAEAE',
+              fontSize: fontSize || '12px',
+              marginLeft: '5px',
+            },
+          }, label),
+        ]),
 
-      showFiat ? h(FiatValue, { value: props.value, conversionRate, currentCurrency }) : null,
-    ]))
+        showFiat ? h(FiatValue, { value: props.value, conversionRate, currentCurrency }) : null,
+      ]))
   )
 }
diff --git a/ui/app/components/fiat-value.js b/ui/app/components/fiat-value.js
index 8a64a1cfc..665789353 100644
--- a/ui/app/components/fiat-value.js
+++ b/ui/app/components/fiat-value.js
@@ -12,7 +12,7 @@ function FiatValue () {
 
 FiatValue.prototype.render = function () {
   const props = this.props
-  const { conversionRate, currentCurrency } = props
+  const { conversionRate, currentCurrency, style } = props
 
   const value = formatBalance(props.value, 6)
 
@@ -28,16 +28,18 @@ FiatValue.prototype.render = function () {
     fiatTooltipNumber = 'Unknown'
   }
 
-  return fiatDisplay(fiatDisplayNumber, currentCurrency)
+  return fiatDisplay(fiatDisplayNumber, currentCurrency, style)
 }
 
-function fiatDisplay (fiatDisplayNumber, fiatSuffix) {
+function fiatDisplay (fiatDisplayNumber, fiatSuffix, styleOveride = {}) {
+  const { fontSize, color, fontFamily, lineHeight } = styleOveride
+
   if (fiatDisplayNumber !== 'N/A') {
     return h('.flex-row', {
       style: {
         alignItems: 'flex-end',
-        lineHeight: '13px',
-        fontFamily: 'Montserrat Light',
+        lineHeight: lineHeight || '13px',
+        fontFamily: fontFamily || 'Montserrat Light',
         textRendering: 'geometricPrecision',
       },
     }, [
@@ -45,15 +47,15 @@ function fiatDisplay (fiatDisplayNumber, fiatSuffix) {
         style: {
           width: '100%',
           textAlign: 'right',
-          fontSize: '12px',
-          color: '#333333',
+          fontSize: fontSize || '12px',
+          color: color || '#333333',
         },
       }, fiatDisplayNumber),
       h('div', {
         style: {
-          color: '#AEAEAE',
+          color: color || '#AEAEAE',
           marginLeft: '5px',
-          fontSize: '12px',
+          fontSize: fontSize || '12px',
         },
       }, fiatSuffix),
     ])
diff --git a/ui/app/components/gas-tooltip.js b/ui/app/components/gas-tooltip.js
new file mode 100644
index 000000000..68b7aea61
--- /dev/null
+++ b/ui/app/components/gas-tooltip.js
@@ -0,0 +1,102 @@
+const Component = require('react').Component
+const h = require('react-hyperscript')
+const inherits = require('util').inherits
+const InputNumber = require('./input-number.js')
+const findDOMNode = require('react-dom').findDOMNode
+
+module.exports = GasTooltip
+
+inherits(GasTooltip, Component)
+function GasTooltip () {
+  Component.call(this)
+  this.state = {
+    gasLimit: 0,
+    gasPrice: 0,
+  }
+
+  this.updateGasPrice = this.updateGasPrice.bind(this);
+  this.updateGasLimit = this.updateGasLimit.bind(this);
+  this.onClose = this.onClose.bind(this);
+}
+
+GasTooltip.prototype.componentWillMount = function () {
+  const { gasPrice = 0, gasLimit = 0} = this.props
+  
+  this.setState({
+    gasPrice: parseInt(gasPrice, 16) / 1000000000,
+    gasLimit: parseInt(gasLimit, 16),
+  })
+}
+
+GasTooltip.prototype.updateGasPrice = function (newPrice) {
+  const { onFeeChange } = this.props
+  const { gasLimit } = this.state
+
+  this.setState({ gasPrice: newPrice })
+  onFeeChange({
+    gasLimit: gasLimit.toString(16),
+    gasPrice: (newPrice * 1000000000).toString(16)
+  })
+}
+
+GasTooltip.prototype.updateGasLimit = function (newLimit) {
+  const { onFeeChange } = this.props
+  const { gasPrice } = this.state
+
+  this.setState({ gasLimit: newLimit })
+  onFeeChange({
+    gasLimit: newLimit.toString(16),
+    gasPrice: (gasPrice * 1000000000).toString(16)
+  })
+}
+
+GasTooltip.prototype.onClose = function (e) {
+  e.stopPropagation();
+  this.props.onClose();
+}
+
+GasTooltip.prototype.render = function () {
+  const { position, title, children, className } = this.props
+  const { gasPrice, gasLimit } = this.state
+
+  return h('div.gas-tooltip', {}, [
+    h('div.gas-tooltip-close-area', {
+      onClick: this.onClose
+    }),
+    h('div.customize-gas-tooltip-container', {}, [
+      h('div.customize-gas-tooltip', {}, [
+        h('div.gas-tooltip-header.gas-tooltip-label', {}, ['Customize Gas']),
+        h('div.gas-tooltip-input-label', {}, [
+          h('span.gas-tooltip-label', {}, ['Gas Price']),
+          h('i.fa.fa-info-circle')
+        ]),
+        h(InputNumber, {
+          unitLabel: 'GWEI',
+          step: 1,
+          min: 0,
+          placeholder: '0',
+          initValue: gasPrice,
+          onChange: (newPrice) => this.updateGasPrice(newPrice), 
+        }),
+        h('div.gas-tooltip-input-label', {
+          style: {
+            'marginTop': '81px',
+          },
+        }, [
+          h('span.gas-tooltip-label', {}, ['Gas Limit']),
+          h('i.fa.fa-info-circle')
+        ]),
+        h(InputNumber, {
+          unitLabel: 'UNITS',
+          step: 1,
+          min: 0,
+          placeholder: '0',
+          initValue: gasLimit,
+          onChange: (newLimit) => this.updateGasLimit(newLimit),  
+        }),
+      ]),
+      h('div.gas-tooltip-arrow', {}),
+    ])
+  ])
+}
+
diff --git a/ui/app/components/input-number.js b/ui/app/components/input-number.js
new file mode 100644
index 000000000..c8bdd5ec5
--- /dev/null
+++ b/ui/app/components/input-number.js
@@ -0,0 +1,57 @@
+const Component = require('react').Component
+const h = require('react-hyperscript')
+const inherits = require('util').inherits
+const findDOMNode = require('react-dom').findDOMNode
+
+module.exports = InputNumber
+
+inherits(InputNumber, Component)
+function InputNumber () {
+  Component.call(this)
+
+  this.state = {
+    value: 0,
+  }
+
+  this.setValue = this.setValue.bind(this);
+}
+
+InputNumber.prototype.componentWillMount = function () {
+  const { initValue = 0 } = this.props
+  
+  this.setState({ value: initValue });
+}
+
+InputNumber.prototype.setValue = function (newValue) {
+  const { fixed, min, onChange } = this.props
+
+  if (fixed) newValue = Number(newValue.toFixed(4))
+
+  if (newValue >= min) {
+    this.setState({ value: newValue })
+    onChange(newValue)
+  }
+}
+
+InputNumber.prototype.render = function () {
+  const { unitLabel, step = 1, min, placeholder } = this.props
+  const { value } = this.state
+  
+  return h('div.customize-gas-input-wrapper', {}, [
+    h('input.customize-gas-input', {
+      placeholder,
+      type: 'number',
+      value,
+      onChange: (e) => this.setValue(Number(e.target.value))
+    }),
+    h('span.gas-tooltip-input-detail', {}, [unitLabel]),
+    h('div.gas-tooltip-input-arrows', {}, [
+      h('i.fa.fa-angle-up', {
+        onClick: () => this.setValue(value + step)
+      }),
+      h('i.fa.fa-angle-down', {
+        onClick: () => this.setValue(value - step)
+      }),
+    ]),
+  ])
+}
diff --git a/ui/app/components/tooltip.js b/ui/app/components/tooltip.js
index edbc074bb..74cf1ae43 100644
--- a/ui/app/components/tooltip.js
+++ b/ui/app/components/tooltip.js
@@ -12,7 +12,7 @@ function Tooltip () {
 
 Tooltip.prototype.render = function () {
   const props = this.props
-  const { position, title, children } = props
+  const { position, title, children, show = true } = props
 
   return h(ReactTooltip, {
     position: position || 'left',
diff --git a/ui/app/css/itcss/components/send.scss b/ui/app/css/itcss/components/send.scss
index 7c84d3b9f..507351cd1 100644
--- a/ui/app/css/itcss/components/send.scss
+++ b/ui/app/css/itcss/components/send.scss
@@ -6,6 +6,7 @@
   z-index: $send-card-z-index;
   position: absolute;
   top: 5%;
+  font-family: 'DIN OT';
 
   @media screen and (max-width: $break-small) {
     top: 33px;
@@ -45,6 +46,7 @@
 
 .send-screen-input-wrapper {
   width: 95%;
+  position: relative;
 }
 
 .send-screen-input {
@@ -53,9 +55,18 @@
 
 .send-screen-gas-input {
   width: 100%;
-  background-color: $concrete;
+  height: 41px;
+  border-radius: 3px;
+  background-color: #f3f3f3;
   border-width: 0px;
   border-style: none;
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  padding-left: 10px;
+  padding-right: 12px;
+  font-size: 16px;
+  color: $scorpion;
 }
 
 .send-screen-amount-labels {
@@ -70,4 +81,128 @@
   justify-content: space-between;
 }
 
-.send-screen-bolt-icon {}
\ No newline at end of file
+.selected-currency {
+  color: $curious-blue;
+}
+
+.unselected-currency {
+  cursor: pointer;
+}
+
+.send-screen-gas-input-customize {
+  color: $curious-blue;
+  font-size: 12px;
+  cursor: pointer;
+}
+
+.gas-tooltip-close-area {
+  position: fixed;
+  top: 0;
+  left: 0;
+  z-index: 1000;
+  width: 100%;
+  height: 100%;
+}
+
+.customize-gas-tooltip-container {
+  position: absolute;
+  bottom: 50px;
+  width: 237px;
+  height: 307px;
+  background-color: white;
+  opacity: 1;
+  box-shadow: grey 0px 0px 5px;
+  z-index: 1050;
+  padding: 13px 19px;
+  font-size: 16px;
+  border-radius: 4px;
+  font-family: 'Lato';
+  font-weigth: 500;
+}
+
+.gas-tooltip-arrow {
+  height: 25px;
+  width: 25px;
+  z-index: 1200;
+  background: white;
+  position: absolute;
+  -webkit-transform: rotate(45deg);
+  transform: rotate(45deg);
+  left: 107px;
+  top: 294px;
+  -webkit-box-shadow: 0 0 5px grey;
+  box-shadow: 2px 2px 2px $alto;
+}
+
+.customize-gas-tooltip-container input[type=number]::-webkit-inner-spin-button { 
+    -webkit-appearance: none;
+    display:none;
+}
+
+.customize-gas-tooltip-container input[type=number]:hover::-webkit-inner-spin-button { 
+    -webkit-appearance: none;
+    display:none;
+}  
+
+.customize-gas-tooltip {
+  position: relative;
+}
+
+.gas-tooltip {
+  display: flex;
+  justify-content: center;
+}
+
+.gas-tooltip-label {
+  font-size: 16px;
+  color: $tundora;
+}
+
+.gas-tooltip-header {
+  padding-bottom: 12px;
+}
+
+.gas-tooltip-input-label {
+  margin-bottom: 5px;
+}
+
+.gas-tooltip-input-label i {
+  color: $silver-chalice;
+  margin-left: 6px;
+}
+
+.customize-gas-input {
+  width: 178px;
+  height: 28px;
+  border: 1px solid $alto;
+  font-size: 16px;
+  color: $nile-blue;
+  padding-left: 8px;
+}
+
+.customize-gas-input-wrapper {
+  position: relative;
+}
+
+.gas-tooltip-input-detail {
+  position: absolute;
+  top: 4px;
+  right: 26px;
+  font-size: 12px;
+  color: $silver-chalice;
+}
+
+.gas-tooltip-input-arrows {
+  position: absolute;
+  top: 0px;
+  left: 178px;
+  width: 17px;
+  height: 28px;
+  border: 1px solid #dadada;
+  border-left: 0px;
+  display: flex;
+  flex-direction: column;
+  color: #9b9b9b;
+  font-size: 0.8em;
+  padding: 1px 4px;
+}
\ No newline at end of file
diff --git a/ui/app/css/itcss/settings/typography.scss b/ui/app/css/itcss/settings/typography.scss
index e18a1979d..8051b5fe3 100644
--- a/ui/app/css/itcss/settings/typography.scss
+++ b/ui/app/css/itcss/settings/typography.scss
@@ -41,3 +41,10 @@
   font-weight: 400;
   font-style: normal;
 }
+
+@font-face {
+  font-family: 'Lato';
+  src: url('/fonts/Lato/Lato-Regular.ttf') format('truetype');
+  font-weight: 400;
+  font-style: normal;
+}
diff --git a/ui/app/css/itcss/settings/variables.scss b/ui/app/css/itcss/settings/variables.scss
index 2f5f17f17..ac719e50b 100644
--- a/ui/app/css/itcss/settings/variables.scss
+++ b/ui/app/css/itcss/settings/variables.scss
@@ -29,6 +29,7 @@ $curious-blue: #2f9ae0;
 $concrete: #f3f3f3;
 $tundora: #4d4d4d;
 $nile-blue: #1b344d;
+$scorpion: #5d5d5d;
 
 /*
   Z-Indicies
diff --git a/ui/app/send.js b/ui/app/send.js
index ef4e92e26..848f53f7c 100644
--- a/ui/app/send.js
+++ b/ui/app/send.js
@@ -5,13 +5,19 @@ const connect = require('react-redux').connect
 const Identicon = require('./components/identicon')
 const actions = require('./actions')
 const util = require('./util')
+const ethUtil = require('ethereumjs-util')
+const BN = ethUtil.BN
+const hexToBn = require('../../app/scripts/lib/hex-to-bn')
 const numericBalance = require('./util').numericBalance
 const addressSummary = require('./util').addressSummary
+const bnMultiplyByFraction = require('./util').bnMultiplyByFraction
 const isHex = require('./util').isHex
 const EthBalance = require('./components/eth-balance')
 const EnsInput = require('./components/ens-input')
-const ethUtil = require('ethereumjs-util')
+const FiatValue = require('./components/fiat-value.js')
+const GasTooltip = require('./components/gas-tooltip.js')
 const { getSelectedIdentity } = require('./selectors')
+const getTxFeeBn = require('./util').getTxFeeBn
 
 const ARAGON = '960b236A07cf122663c4303350609A66A7B288C0'
 
@@ -28,6 +34,7 @@ function mapStateToProps (state) {
     addressBook: state.metamask.addressBook,
     conversionRate: state.metamask.conversionRate,
     currentCurrency: state.metamask.currentCurrency,
+    blockGasLimit: state.metamask.currentBlockGasLimit,
   }
 
   result.error = result.warning && result.warning.split('.')[0]
@@ -51,12 +58,20 @@ function SendTransactionScreen () {
       to: '',
       // these values are hardcoded, so "Next" can be clicked
       amount: '0.0001', // see L544
-      gasPrice: '4a817c800',
+      gasPrice: '0x5d21dba00',
       gas: '0x7b0d',
       txData: null,
       memo: '',
     },
+    tooltipIsOpen: false,
   }
+
+  this.back = this.back.bind(this)
+  this.closeTooltip = this.closeTooltip.bind(this)
+  this.onSubmit = this.onSubmit.bind(this)
+  this.recipientDidChange = this.recipientDidChange.bind(this)
+  this.setCurrentCurrency = this.setCurrentCurrency.bind(this)
+  this.toggleTooltip = this.toggleTooltip.bind(this)
 }
 
 SendTransactionScreen.prototype.render = function () {
@@ -74,6 +89,8 @@ SendTransactionScreen.prototype.render = function () {
     conversionRate,
     currentCurrency,
   } = props
+  const { blockGasLimit, newTx } = this.state
+  const { gas, gasPrice } = newTx
 
   console.log({ selectedIdentity, identities })
   console.log("SendTransactionScreen state:", this.state)
@@ -174,7 +191,17 @@ SendTransactionScreen.prototype.render = function () {
 
           h('div.send-screen-amount-labels', {}, [
             h('span', {}, ['Amount']),
-            h('span', {}, ['ETH <> USD']), //holding on icon from design
+            h('span', {}, [
+              h('span', {
+                className: currentCurrency === 'ETH' ? 'selected-currency' : 'unselected-currency',
+                onClick: () => this.setCurrentCurrency('ETH') 
+              }, ['ETH']),
+              '<>',
+              h('span', {
+                className: currentCurrency === 'USD' ? 'selected-currency' : 'unselected-currency',
+                onClick: () => this.setCurrentCurrency('USD'), 
+              }, ['USD']),
+            ]), //holding on icon from design
           ]),
 
           h('input.large-input.send-screen-input', {
@@ -195,6 +222,21 @@ SendTransactionScreen.prototype.render = function () {
         ]),
 
         h('div.send-screen-input-wrapper', {}, [
+          this.state.tooltipIsOpen && h(GasTooltip, {
+            className: 'send-tooltip',
+            gasPrice,
+            gasLimit: gas,
+            onClose: this.closeTooltip,
+            onFeeChange: ({gasLimit, gasPrice}) => {
+              this.setState({
+                newTx: {
+                  ...this.state.newTx,
+                  gas: gasLimit,
+                  gasPrice,
+                },
+              })
+            }
+          }),
 
           h('div.send-screen-gas-labels', {}, [
             h('span', {}, [
@@ -212,9 +254,39 @@ SendTransactionScreen.prototype.render = function () {
             h('span', {}, ['What\'s this?']),
           ]),
 
-          h('input.large-input.send-screen-gas-input', {
-            placeholder: '0',
-          }, []),
+          // TODO: handle loading time when switching to USD
+          h('div.large-input.send-screen-gas-input', {}, [
+            currentCurrency === 'USD'
+            ? h(FiatValue, {
+              value: getTxFeeBn(gas, gasPrice, blockGasLimit),
+              conversionRate,
+              currentCurrency,
+              style: {
+                color: '#5d5d5d',
+                fontSize: '16px',
+                fontFamily: 'DIN OT',
+                lineHeight: '22.4px'
+              }
+            })
+            : h(EthBalance, {
+                value: getTxFeeBn(gas, gasPrice, blockGasLimit),
+                currentCurrency,
+                conversionRate,
+                showFiat: false,
+                hideTooltip: true,
+                styleOveride: {
+                  color: '#5d5d5d',
+                  fontSize: '16px',
+                  fontFamily: 'DIN OT',
+                  lineHeight: '22.4px'
+                }
+            }),
+            h('div.send-screen-gas-input-customize', {
+              onClick: this.toggleTooltip,
+            }, [
+              'Customize'
+            ]),
+          ]),
 
         ]),
 
@@ -264,7 +336,7 @@ SendTransactionScreen.prototype.render = function () {
       h('section.flex-column.flex-center', [
 
         h('button.btn-light', {
-          onClick: this.onSubmit.bind(this),
+          onClick: this.onSubmit,
           style: {
             marginTop: '8px',
             width: '8em',
@@ -273,7 +345,7 @@ SendTransactionScreen.prototype.render = function () {
         }, 'Next'),
 
         h('button.btn-light', {
-          onClick: this.back.bind(this),
+          onClick: this.back,
           style: {
             background: '#F7F7F7', // $alabaster
             border: 'none',
@@ -392,7 +464,7 @@ SendTransactionScreen.prototype.renderSendToken = function () {
           h(EnsInput, {
             name: 'address',
             placeholder: 'Recipient Address',
-            onChange: this.recipientDidChange.bind(this),
+            onChange: this.recipientDidChange,
             network,
             identities,
             addressBook,
@@ -484,7 +556,7 @@ SendTransactionScreen.prototype.renderSendToken = function () {
       h('section.flex-column.flex-center', [
 
         h('button.btn-light', {
-          onClick: this.onSubmit.bind(this),
+          onClick: this.onSubmit,
           style: {
             marginTop: '8px',
             width: '8em',
@@ -493,7 +565,7 @@ SendTransactionScreen.prototype.renderSendToken = function () {
         }, 'Next'),
 
         h('button.btn-light', {
-          onClick: this.back.bind(this),
+          onClick: this.back,
           style: {
             background: '#F7F7F7', // $alabaster
             border: 'none',
@@ -507,6 +579,18 @@ SendTransactionScreen.prototype.renderSendToken = function () {
   )
 }
 
+SendTransactionScreen.prototype.toggleTooltip = function () {
+  this.setState({ tooltipIsOpen: !this.state.tooltipIsOpen })
+}
+
+SendTransactionScreen.prototype.closeTooltip = function () {
+  this.setState({ tooltipIsOpen: false })
+}
+
+SendTransactionScreen.prototype.setCurrentCurrency = function (newCurrency) {
+  this.props.dispatch(actions.setCurrentCurrency(newCurrency))
+}
+
 SendTransactionScreen.prototype.navigateToAccounts = function (event) {
   event.stopPropagation()
   this.props.dispatch(actions.showAccountsPage())
diff --git a/ui/app/util.js b/ui/app/util.js
index 4dd0e30f3..a624726e2 100644
--- a/ui/app/util.js
+++ b/ui/app/util.js
@@ -1,4 +1,5 @@
 const ethUtil = require('ethereumjs-util')
+const hexToBn = require('../../app/scripts/lib/hex-to-bn')
 const vreme = new (require('vreme'))()
 
 // formatData :: ( date: <Unix Timestamp> ) -> String
@@ -43,6 +44,8 @@ module.exports = {
   bnTable: bnTable,
   isHex: isHex,
   formatDate,
+  bnMultiplyByFraction,
+  getTxFeeBn,
 }
 
 function valuesFor (obj) {
@@ -222,3 +225,22 @@ function readableDate (ms) {
 function isHex (str) {
   return Boolean(str.match(/^(0x)?[0-9a-fA-F]+$/))
 }
+
+function bnMultiplyByFraction (targetBN, numerator, denominator) {
+  const numBN = new ethUtil.BN(numerator)
+  const denomBN = new ethUtil.BN(denominator)
+  return targetBN.mul(numBN).div(denomBN)
+}
+
+function getTxFeeBn (gas, gasPrice = MIN_GAS_PRICE_BN.toString(16), blockGasLimit) {
+  // Gas Limit
+  const gasBn = hexToBn(gas)
+  const gasLimit = new ethUtil.BN(parseInt(blockGasLimit))
+  const safeGasLimit = bnMultiplyByFraction(gasLimit, 19, 20).toString(10)
+
+  // Gas Price
+  const gasPriceBn = hexToBn(gasPrice)
+  const txFeeBn = gasBn.mul(gasPriceBn)
+
+  return txFeeBn.toString(16);
+}