[ML] Fix Single Metric Viewer for multi week bucket spans (#19759)

* [ML] Fix Single Metric Viewer for multi week bucket spans

* [ML] Edit to comment in ML time buckets calcEsInterval

Author: peteharverson

x-pack/plugins/ml/public/util/__tests__/ml_time_buckets.js

@@ -9,7 +9,10 @@
 import ngMock from 'ng_mock';
 import expect from 'expect.js';
 import moment from 'moment';
-import { IntervalHelperProvider, getBoundsRoundedToInterval } from '../ml_time_buckets';
+import {
+  IntervalHelperProvider,
+  getBoundsRoundedToInterval,
+  calcEsInterval } from '../ml_time_buckets';
 
 describe('ML - time buckets', () => {
 
@@ -125,7 +128,7 @@ describe('ML - time buckets', () => {
 
   });
 
-  describe('getBoundsRoundedToInterval ', () => {
+  describe('getBoundsRoundedToInterval', () => {
     // Must include timezone when creating moments for this test to ensure
     // checks are correct when running tests in different timezones.
     const testBounds = { min: moment('2017-01-05T10:11:12.000+00:00'), max: moment('2017-10-26T09:08:07.000+00:00') };
@@ -156,4 +159,24 @@ describe('ML - time buckets', () => {
 
   });
 
+  describe('calcEsInterval', () => {
+    it('returns correct interval for various durations', () => {
+      expect(calcEsInterval(moment.duration(500, 'ms'))).to.eql({ value: 500, unit: 'ms', expression: '500ms' });
+      expect(calcEsInterval(moment.duration(1000, 'ms'))).to.eql({ value: 1, unit: 's', expression: '1s' });
+      expect(calcEsInterval(moment.duration(15, 's'))).to.eql({ value: 15, unit: 's', expression: '15s' });
+      expect(calcEsInterval(moment.duration(60, 's'))).to.eql({ value: 1, unit: 'm', expression: '1m' });
+      expect(calcEsInterval(moment.duration(1, 'm'))).to.eql({ value: 1, unit: 'm', expression: '1m' });
+      expect(calcEsInterval(moment.duration(60, 'm'))).to.eql({ value: 1, unit: 'h', expression: '1h' });
+      expect(calcEsInterval(moment.duration(3, 'h'))).to.eql({ value: 3, unit: 'h', expression: '3h' });
+      expect(calcEsInterval(moment.duration(24, 'h'))).to.eql({ value: 1, unit: 'd', expression: '1d' });
+      expect(calcEsInterval(moment.duration(3, 'd'))).to.eql({ value: 3, unit: 'd', expression: '3d' });
+      expect(calcEsInterval(moment.duration(7, 'd'))).to.eql({ value: 1, unit: 'w', expression: '1w' });
+      expect(calcEsInterval(moment.duration(1, 'w'))).to.eql({ value: 1, unit: 'w', expression: '1w' });
+      expect(calcEsInterval(moment.duration(4, 'w'))).to.eql({ value: 28, unit: 'd', expression: '28d' });
+      expect(calcEsInterval(moment.duration(1, 'M'))).to.eql({ value: 1, unit: 'M', expression: '1M' });
+      expect(calcEsInterval(moment.duration(12, 'M'))).to.eql({ value: 1, unit: 'y', expression: '1y' });
+      expect(calcEsInterval(moment.duration(1, 'y'))).to.eql({ value: 1, unit: 'y', expression: '1y' });
+    });
+  });
+
 });

x-pack/plugins/ml/public/util/ml_time_buckets.js

@@ -6,17 +6,20 @@
 
 
 
-// custom TimeBuckets which inherits from the standrd kibana TimeBuckets
+// custom TimeBuckets which inherits from the standard kibana TimeBuckets
 // this adds the ability to override the barTarget and maxBars settings
 // allowing for a more granular visualization interval without having to
 // modify the global settings stored in the kibana config
 
 import _ from 'lodash';
 import moment from 'moment';
+import dateMath from '@kbn/datemath';
 
 import { TimeBucketsCalcAutoIntervalProvider } from 'plugins/ml/util/ml_calc_auto_interval';
 import { inherits } from 'plugins/ml/util/inherits';
-import { calcEsInterval } from 'ui/time_buckets/calc_es_interval';
+
+const unitsDesc = dateMath.unitsDesc;
+const largeMax = unitsDesc.indexOf('w');    // Multiple units of week or longer converted to days for ES intervals.
 
 import { TimeBuckets } from 'ui/time_buckets';
 export function IntervalHelperProvider(Private, timefilter, config) {
@@ -147,3 +150,39 @@ export function getBoundsRoundedToInterval(bounds, interval, inclusiveEnd = fals
   }
   return { min: moment(adjustedMinMs), max: moment(adjustedMaxMs) };
 }
+
+export function calcEsInterval(duration) {
+  // Converts a moment.duration into an Elasticsearch compatible interval expression,
+  // and provides associated metadata.
+
+  // Note this is a copy of Kibana's ui/time_buckets/calc_es_interval,
+  // but with the definition of a 'large' unit changed from 'M' to 'w',
+  // bringing it into line with the time units supported by Elasticsearch
+  for (let i = 0; i < unitsDesc.length; i++) {
+    const unit = unitsDesc[i];
+    const val = duration.as(unit);
+    // find a unit that rounds neatly
+    if (val >= 1 && Math.floor(val) === val) {
+
+      // if the unit is "large", like years, but isn't set to 1, ES will throw an error.
+      // So keep going until we get out of the "large" units.
+      if (i <= largeMax && val !== 1) {
+        continue;
+      }
+
+      return {
+        value: val,
+        unit: unit,
+        expression: val + unit
+      };
+    }
+  }
+
+  const ms = duration.as('ms');
+  return {
+    value: ms,
+    unit: 'ms',
+    expression: ms + 'ms'
+  };
+}
+