1 files changed, 468 insertions, 0 deletions
diff --git a/ui/app/ducks/gas.duck.js b/ui/app/ducks/gas.duck.js
new file mode 100644
index 000000000..8db24cc83
--- /dev/null
+++ b/ui/app/ducks/gas.duck.js
@@ -0,0 +1,468 @@
+import { clone, uniqBy, flatten } from 'ramda'
+import BigNumber from 'bignumber.js'
+import {
+  loadLocalStorageData,
+  saveLocalStorageData,
+} from '../../lib/local-storage-helpers'
+
+// Actions
+const BASIC_GAS_ESTIMATE_LOADING_FINISHED = 'metamask/gas/BASIC_GAS_ESTIMATE_LOADING_FINISHED'
+const BASIC_GAS_ESTIMATE_LOADING_STARTED = 'metamask/gas/BASIC_GAS_ESTIMATE_LOADING_STARTED'
+const GAS_ESTIMATE_LOADING_FINISHED = 'metamask/gas/GAS_ESTIMATE_LOADING_FINISHED'
+const GAS_ESTIMATE_LOADING_STARTED = 'metamask/gas/GAS_ESTIMATE_LOADING_STARTED'
+const RESET_CUSTOM_GAS_STATE = 'metamask/gas/RESET_CUSTOM_GAS_STATE'
+const RESET_CUSTOM_DATA = 'metamask/gas/RESET_CUSTOM_DATA'
+const SET_BASIC_GAS_ESTIMATE_DATA = 'metamask/gas/SET_BASIC_GAS_ESTIMATE_DATA'
+const SET_CUSTOM_GAS_ERRORS = 'metamask/gas/SET_CUSTOM_GAS_ERRORS'
+const SET_CUSTOM_GAS_LIMIT = 'metamask/gas/SET_CUSTOM_GAS_LIMIT'
+const SET_CUSTOM_GAS_PRICE = 'metamask/gas/SET_CUSTOM_GAS_PRICE'
+const SET_CUSTOM_GAS_TOTAL = 'metamask/gas/SET_CUSTOM_GAS_TOTAL'
+const SET_PRICE_AND_TIME_ESTIMATES = 'metamask/gas/SET_PRICE_AND_TIME_ESTIMATES'
+const SET_API_ESTIMATES_LAST_RETRIEVED = 'metamask/gas/SET_API_ESTIMATES_LAST_RETRIEVED'
+const SET_BASIC_API_ESTIMATES_LAST_RETRIEVED = 'metamask/gas/SET_BASIC_API_ESTIMATES_LAST_RETRIEVED'
+
+// TODO: determine if this approach to initState is consistent with conventional ducks pattern
+const initState = {
+  customData: {
+    price: null,
+    limit: '0x5208',
+  },
+  basicEstimates: {
+    average: null,
+    fastestWait: null,
+    fastWait: null,
+    fast: null,
+    safeLowWait: null,
+    blockNum: null,
+    avgWait: null,
+    blockTime: null,
+    speed: null,
+    fastest: null,
+    safeLow: null,
+  },
+  basicEstimateIsLoading: true,
+  gasEstimatesLoading: true,
+  priceAndTimeEstimates: [],
+  basicPriceAndTimeEstimates: [],
+  priceAndTimeEstimatesLastRetrieved: 0,
+  basicPriceAndTimeEstimatesLastRetrieved: 0,
+  errors: {},
+}
+
+// Reducer
+export default function reducer ({ gas: gasState = initState }, action = {}) {
+  const newState = clone(gasState)
+
+  switch (action.type) {
+    case BASIC_GAS_ESTIMATE_LOADING_STARTED:
+      return {
+        ...newState,
+        basicEstimateIsLoading: true,
+      }
+    case BASIC_GAS_ESTIMATE_LOADING_FINISHED:
+      return {
+        ...newState,
+        basicEstimateIsLoading: false,
+      }
+    case GAS_ESTIMATE_LOADING_STARTED:
+      return {
+        ...newState,
+        gasEstimatesLoading: true,
+      }
+    case GAS_ESTIMATE_LOADING_FINISHED:
+      return {
+        ...newState,
+        gasEstimatesLoading: false,
+      }
+    case SET_BASIC_GAS_ESTIMATE_DATA:
+      return {
+        ...newState,
+        basicEstimates: action.value,
+      }
+    case SET_CUSTOM_GAS_PRICE:
+      return {
+        ...newState,
+        customData: {
+          ...newState.customData,
+          price: action.value,
+        },
+      }
+    case SET_CUSTOM_GAS_LIMIT:
+      return {
+        ...newState,
+        customData: {
+          ...newState.customData,
+          limit: action.value,
+        },
+      }
+    case SET_CUSTOM_GAS_TOTAL:
+      return {
+        ...newState,
+        customData: {
+          ...newState.customData,
+          total: action.value,
+        },
+      }
+    case SET_PRICE_AND_TIME_ESTIMATES:
+      return {
+        ...newState,
+        priceAndTimeEstimates: action.value,
+      }
+    case SET_CUSTOM_GAS_ERRORS:
+      return {
+        ...newState,
+        errors: {
+          ...newState.errors,
+          ...action.value,
+        },
+      }
+    case SET_API_ESTIMATES_LAST_RETRIEVED:
+      return {
+        ...newState,
+        priceAndTimeEstimatesLastRetrieved: action.value,
+      }
+    case SET_BASIC_API_ESTIMATES_LAST_RETRIEVED:
+      return {
+        ...newState,
+        basicPriceAndTimeEstimatesLastRetrieved: action.value,
+      }
+    case RESET_CUSTOM_DATA:
+      return {
+        ...newState,
+        customData: clone(initState.customData),
+      }
+    case RESET_CUSTOM_GAS_STATE:
+      return clone(initState)
+    default:
+      return newState
+  }
+}
+
+// Action Creators
+export function basicGasEstimatesLoadingStarted () {
+  return {
+    type: BASIC_GAS_ESTIMATE_LOADING_STARTED,
+  }
+}
+
+export function basicGasEstimatesLoadingFinished () {
+  return {
+    type: BASIC_GAS_ESTIMATE_LOADING_FINISHED,
+  }
+}
+
+export function gasEstimatesLoadingStarted () {
+  return {
+    type: GAS_ESTIMATE_LOADING_STARTED,
+  }
+}
+
+export function gasEstimatesLoadingFinished () {
+  return {
+    type: GAS_ESTIMATE_LOADING_FINISHED,
+  }
+}
+
+export function fetchBasicGasEstimates () {
+  return (dispatch) => {
+    dispatch(basicGasEstimatesLoadingStarted())
+
+    return fetch('https://dev.blockscale.net/api/gasexpress.json', {
+      'headers': {},
+      'referrer': 'https://dev.blockscale.net/api/',
+      'referrerPolicy': 'no-referrer-when-downgrade',
+      'body': null,
+      'method': 'GET',
+      'mode': 'cors'}
+    )
+      .then(r => r.json())
+      .then(({
+        safeLow,
+        standard: average,
+        fast,
+        fastest,
+        block_time: blockTime,
+        blockNum,
+      }) => {
+        const basicEstimates = {
+          safeLow,
+          average,
+          fast,
+          fastest,
+          blockTime,
+          blockNum,
+        }
+        dispatch(setBasicGasEstimateData(basicEstimates))
+        dispatch(basicGasEstimatesLoadingFinished())
+        return basicEstimates
+      })
+  }
+}
+
+export function fetchBasicGasAndTimeEstimates () {
+  return (dispatch, getState) => {
+    const {
+      basicPriceAndTimeEstimatesLastRetrieved,
+      basicPriceAndTimeEstimates,
+    } = getState().gas
+    const timeLastRetrieved = basicPriceAndTimeEstimatesLastRetrieved || loadLocalStorageData('BASIC_GAS_AND_TIME_API_ESTIMATES_LAST_RETRIEVED') || 0
+
+    dispatch(basicGasEstimatesLoadingStarted())
+
+    const promiseToFetch = Date.now() - timeLastRetrieved > 75000
+      ? fetch('https://ethgasstation.info/json/ethgasAPI.json', {
+        'headers': {},
+        'referrer': 'http://ethgasstation.info/json/',
+        'referrerPolicy': 'no-referrer-when-downgrade',
+        'body': null,
+        'method': 'GET',
+        'mode': 'cors'}
+      )
+        .then(r => r.json())
+        .then(({
+          average: averageTimes10,
+          avgWait,
+          block_time: blockTime,
+          blockNum,
+          fast: fastTimes10,
+          fastest: fastestTimes10,
+          fastestWait,
+          fastWait,
+          safeLow: safeLowTimes10,
+          safeLowWait,
+          speed,
+        }) => {
+          const [average, fast, fastest, safeLow] = [
+            averageTimes10,
+            fastTimes10,
+            fastestTimes10,
+            safeLowTimes10,
+          ].map(price => (new BigNumber(price)).div(10).toNumber())
+
+          const basicEstimates = {
+            average,
+            avgWait,
+            blockTime,
+            blockNum,
+            fast,
+            fastest,
+            fastestWait,
+            fastWait,
+            safeLow,
+            safeLowWait,
+            speed,
+          }
+
+          const timeRetrieved = Date.now()
+          dispatch(setBasicApiEstimatesLastRetrieved(timeRetrieved))
+          saveLocalStorageData(timeRetrieved, 'BASIC_GAS_AND_TIME_API_ESTIMATES_LAST_RETRIEVED')
+          saveLocalStorageData(basicEstimates, 'BASIC_GAS_AND_TIME_API_ESTIMATES')
+
+          return basicEstimates
+        })
+      : Promise.resolve(basicPriceAndTimeEstimates.length
+          ? basicPriceAndTimeEstimates
+          : loadLocalStorageData('BASIC_GAS_AND_TIME_API_ESTIMATES')
+        )
+
+      return promiseToFetch.then(basicEstimates => {
+        dispatch(setBasicGasEstimateData(basicEstimates))
+        dispatch(basicGasEstimatesLoadingFinished())
+        return basicEstimates
+      })
+  }
+}
+
+function extrapolateY ({ higherY, lowerY, higherX, lowerX, xForExtrapolation }) {
+  higherY = new BigNumber(higherY, 10)
+  lowerY = new BigNumber(lowerY, 10)
+  higherX = new BigNumber(higherX, 10)
+  lowerX = new BigNumber(lowerX, 10)
+  xForExtrapolation = new BigNumber(xForExtrapolation, 10)
+  const slope = (higherY.minus(lowerY)).div(higherX.minus(lowerX))
+  const newTimeEstimate = slope.times(higherX.minus(xForExtrapolation)).minus(higherY).negated()
+
+  return Number(newTimeEstimate.toPrecision(10))
+}
+
+function getRandomArbitrary (min, max) {
+  min = new BigNumber(min, 10)
+  max = new BigNumber(max, 10)
+  const random = new BigNumber(String(Math.random()), 10)
+  return new BigNumber(random.times(max.minus(min)).plus(min)).toPrecision(10)
+}
+
+function calcMedian (list) {
+  const medianPos = (Math.floor(list.length / 2) + Math.ceil(list.length / 2)) / 2
+  return medianPos === Math.floor(medianPos)
+    ? (list[medianPos - 1] + list[medianPos]) / 2
+    : list[Math.floor(medianPos)]
+}
+
+function quartiles (data) {
+  const lowerHalf = data.slice(0, Math.floor(data.length / 2))
+  const upperHalf = data.slice(Math.floor(data.length / 2) + (data.length % 2 === 0 ? 0 : 1))
+  const median = calcMedian(data)
+  const lowerQuartile = calcMedian(lowerHalf)
+  const upperQuartile = calcMedian(upperHalf)
+  return {
+    median,
+    lowerQuartile,
+    upperQuartile,
+  }
+}
+
+function inliersByIQR (data, prop) {
+  const { lowerQuartile, upperQuartile } = quartiles(data.map(d => prop ? d[prop] : d))
+  const IQR = upperQuartile - lowerQuartile
+  const lowerBound = lowerQuartile - 1.5 * IQR
+  const upperBound = upperQuartile + 1.5 * IQR
+  return data.filter(d => {
+    const value = prop ? d[prop] : d
+    return value >= lowerBound && value <= upperBound
+  })
+}
+
+export function fetchGasEstimates (blockTime) {
+  return (dispatch, getState) => {
+    const {
+      priceAndTimeEstimatesLastRetrieved,
+      priceAndTimeEstimates,
+    } = getState().gas
+    const timeLastRetrieved = priceAndTimeEstimatesLastRetrieved || loadLocalStorageData('GAS_API_ESTIMATES_LAST_RETRIEVED') || 0
+
+    dispatch(gasEstimatesLoadingStarted())
+
+    const promiseToFetch = Date.now() - timeLastRetrieved > 75000
+      ? fetch('https://ethgasstation.info/json/predictTable.json', {
+          'headers': {},
+          'referrer': 'http://ethgasstation.info/json/',
+          'referrerPolicy': 'no-referrer-when-downgrade',
+          'body': null,
+          'method': 'GET',
+          'mode': 'cors'}
+        )
+        .then(r => r.json())
+        .then(r => {
+          const estimatedPricesAndTimes = r.map(({ expectedTime, expectedWait, gasprice }) => ({ expectedTime, expectedWait, gasprice }))
+          const estimatedTimeWithUniquePrices = uniqBy(({ expectedTime }) => expectedTime, estimatedPricesAndTimes)
+
+          const withSupplementalTimeEstimates = flatten(estimatedTimeWithUniquePrices.map(({ expectedWait, gasprice }, i, arr) => {
+            const next = arr[i + 1]
+            if (!next) {
+              return [{ expectedWait, gasprice }]
+            } else {
+              const supplementalPrice = getRandomArbitrary(gasprice, next.gasprice)
+              const supplementalTime = extrapolateY({
+                higherY: next.expectedWait,
+                lowerY: expectedWait,
+                higherX: next.gasprice,
+                lowerX: gasprice,
+                xForExtrapolation: supplementalPrice,
+              })
+              const supplementalPrice2 = getRandomArbitrary(supplementalPrice, next.gasprice)
+              const supplementalTime2 = extrapolateY({
+                higherY: next.expectedWait,
+                lowerY: supplementalTime,
+                higherX: next.gasprice,
+                lowerX: supplementalPrice,
+                xForExtrapolation: supplementalPrice2,
+              })
+              return [
+                { expectedWait, gasprice },
+                { expectedWait: supplementalTime, gasprice: supplementalPrice },
+                { expectedWait: supplementalTime2, gasprice: supplementalPrice2 },
+              ]
+            }
+          }))
+          const withOutliersRemoved = inliersByIQR(withSupplementalTimeEstimates.slice(0).reverse(), 'expectedWait').reverse()
+          const timeMappedToSeconds = withOutliersRemoved.map(({ expectedWait, gasprice }) => {
+            const expectedTime = (new BigNumber(expectedWait)).times(Number(blockTime), 10).toNumber()
+            return {
+              expectedTime,
+              gasprice: (new BigNumber(gasprice, 10).toNumber()),
+            }
+          })
+
+          const timeRetrieved = Date.now()
+          dispatch(setApiEstimatesLastRetrieved(timeRetrieved))
+          saveLocalStorageData(timeRetrieved, 'GAS_API_ESTIMATES_LAST_RETRIEVED')
+          saveLocalStorageData(timeMappedToSeconds, 'GAS_API_ESTIMATES')
+
+          return timeMappedToSeconds
+        })
+      : Promise.resolve(priceAndTimeEstimates.length
+          ? priceAndTimeEstimates
+          : loadLocalStorageData('GAS_API_ESTIMATES')
+        )
+
+      return promiseToFetch.then(estimates => {
+        dispatch(setPricesAndTimeEstimates(estimates))
+        dispatch(gasEstimatesLoadingFinished())
+      })
+  }
+}
+
+export function setBasicGasEstimateData (basicGasEstimateData) {
+  return {
+    type: SET_BASIC_GAS_ESTIMATE_DATA,
+    value: basicGasEstimateData,
+  }
+}
+
+export function setPricesAndTimeEstimates (estimatedPricesAndTimes) {
+  return {
+    type: SET_PRICE_AND_TIME_ESTIMATES,
+    value: estimatedPricesAndTimes,
+  }
+}
+
+export function setCustomGasPrice (newPrice) {
+  return {
+    type: SET_CUSTOM_GAS_PRICE,
+    value: newPrice,
+  }
+}
+
+export function setCustomGasLimit (newLimit) {
+  return {
+    type: SET_CUSTOM_GAS_LIMIT,
+    value: newLimit,
+  }
+}
+
+export function setCustomGasTotal (newTotal) {
+  return {
+    type: SET_CUSTOM_GAS_TOTAL,
+    value: newTotal,
+  }
+}
+
+export function setCustomGasErrors (newErrors) {
+  return {
+    type: SET_CUSTOM_GAS_ERRORS,
+    value: newErrors,
+  }
+}
+
+export function setApiEstimatesLastRetrieved (retrievalTime) {
+  return {
+    type: SET_API_ESTIMATES_LAST_RETRIEVED,
+    value: retrievalTime,
+  }
+}
+
+export function setBasicApiEstimatesLastRetrieved (retrievalTime) {
+  return {
+    type: SET_BASIC_API_ESTIMATES_LAST_RETRIEVED,
+    value: retrievalTime,
+  }
+}
+
+export function resetCustomGasState () {
+  return { type: RESET_CUSTOM_GAS_STATE }
+}
+
+export function resetCustomData () {
+  return { type: RESET_CUSTOM_DATA }
+}