Created PieChart component. Refactored charts.

src/lib/charts.ts

@@ -0,0 +1,27 @@
+import { formatDate } from 'lib/date';
+import { formatLongNumber } from 'lib/format';
+
+export function renderNumberLabels(label: string) {
+  return +label > 1000 ? formatLongNumber(+label) : label;
+}
+
+export function renderDateLabels(unit: string, locale: string) {
+  return (label: string, index: number, values: any[]) => {
+    const d = new Date(values[index].value);
+
+    switch (unit) {
+      case 'minute':
+        return formatDate(d, 'h:mm', locale);
+      case 'hour':
+        return formatDate(d, 'p', locale);
+      case 'day':
+        return formatDate(d, 'MMM d', locale);
+      case 'month':
+        return formatDate(d, 'MMM', locale);
+      case 'year':
+        return formatDate(d, 'YYY', locale);
+      default:
+        return label;
+    }
+  };
+}