chore(server): Move api-server in to it's own DIR

api-server/server/utils/user-stats.js

@@ -0,0 +1,91 @@
+import compose from 'lodash/fp/compose';
+import map from 'lodash/fp/map';
+import sortBy from 'lodash/fp/sortBy';
+import trans from 'lodash/fp/transform';
+import last from 'lodash/fp/last';
+import forEachRight from 'lodash/fp/forEachRight';
+import moment from 'moment-timezone';
+import { dayCount } from '../utils/date-utils';
+
+const transform = trans.convert({ cap: false });
+
+const hoursBetween = 24;
+const hoursDay = 24;
+
+export function prepUniqueDaysByHours(cals, tz = 'UTC') {
+
+  let prev = null;
+
+  // compose goes bottom to top (map > sortBy > transform)
+  return compose(
+    transform((data, cur, i) => {
+      if (i < 1) {
+        data.push(cur);
+        prev = cur;
+      } else if (
+        moment(cur)
+          .tz(tz)
+          .diff(moment(prev).tz(tz).startOf('day'), 'hours')
+        >= hoursDay
+      ) {
+        data.push(cur);
+        prev = cur;
+      }
+    }, []),
+    sortBy(e => e),
+    map(ts => moment(ts).tz(tz).startOf('hours').valueOf())
+  )(cals);
+}
+
+export function calcCurrentStreak(cals, tz = 'UTC') {
+
+  let prev = last(cals);
+  if (
+    moment()
+      .tz(tz)
+      .startOf('day')
+      .diff(moment(prev).tz(tz), 'hours')
+    > hoursBetween
+  ) {
+    return 0;
+  }
+  let currentStreak = 0;
+  let streakContinues = true;
+  forEachRight(cur => {
+    if (
+      moment(prev)
+        .tz(tz)
+        .startOf('day')
+        .diff(moment(cur).tz(tz), 'hours')
+      <= hoursBetween
+    ) {
+      prev = cur;
+      currentStreak++;
+    } else {
+      // current streak found
+      streakContinues = false;
+    }
+    return streakContinues;
+  })(cals);
+
+  return currentStreak;
+}
+
+export function calcLongestStreak(cals, tz = 'UTC') {
+
+  let tail = cals[0];
+  const longest = cals.reduce((longest, head, index) => {
+    const last = cals[index === 0 ? 0 : index - 1];
+    // is streak broken
+    if (moment(head).tz(tz).startOf('day').diff(moment(last).tz(tz), 'hours')
+        > hoursBetween) {
+      tail = head;
+    }
+    if (dayCount(longest, tz) < dayCount([head, tail], tz)) {
+      return [head, tail];
+    }
+    return longest;
+  }, [cals[0], cals[0]]);
+
+  return dayCount(longest, tz);
+}