Refactor chart components.

components/metrics/Legend.js

@@ -0,0 +1,40 @@
+import React from 'react';
+import classNames from 'classnames';
+import Dot from 'components/common/Dot';
+import useLocale from 'hooks/useLocale';
+import styles from './Legend.module.css';
+import useForceUpdate from '../../hooks/useForceUpdate';
+
+export default function Legend({ chart }) {
+  const [locale] = useLocale();
+  const forceUpdate = useForceUpdate();
+
+  function handleClick(index) {
+    const meta = chart.getDatasetMeta(index);
+
+    meta.hidden = meta.hidden === null ? !chart.data.datasets[index].hidden : null;
+
+    chart.update();
+
+    forceUpdate();
+  }
+
+  if (!chart?.legend?.legendItems.find(({ text }) => text)) {
+    return null;
+  }
+
+  return (
+    <div className={styles.legend}>
+      {chart.legend.legendItems.map(({ text, fillStyle, datasetIndex, hidden }) => (
+        <div
+          key={text}
+          className={classNames(styles.label, { [styles.hidden]: hidden })}
+          onClick={() => handleClick(datasetIndex)}
+        >
+          <Dot color={fillStyle} />
+          <span className={locale}>{text}</span>
+        </div>
+      ))}
+    </div>
+  );
+}