first commit

resources/client/people/person-age.tsx

@@ -0,0 +1,43 @@
+import {Person} from '@app/titles/models/person';
+import {FormattedDateTimeRange} from '@common/i18n/formatted-date-time-range';
+import {Fragment, memo} from 'react';
+
+interface Props {
+  person: Person;
+  showRange?: boolean;
+}
+export const PersonAge = memo(({person, showRange}: Props) => {
+  if (showRange && person.birth_date && person.death_date) {
+    return (
+      <FormattedDateTimeRange
+        start={person.birth_date}
+        end={person.death_date}
+        options={{year: 'numeric'}}
+      />
+    );
+  }
+
+  if (person.birth_date) {
+    return (
+      <Fragment>
+        {calculateAgeFromBirthDate(person.birth_date, person.death_date)}
+      </Fragment>
+    );
+  }
+
+  return null;
+});
+
+function calculateAgeFromBirthDate(
+  _birthDate: string,
+  _deathDate?: string
+): number {
+  const until = _deathDate ? new Date(_deathDate) : new Date();
+  const birthDate = new Date(_birthDate);
+  let age = until.getFullYear() - birthDate.getFullYear();
+  const m = until.getMonth() - birthDate.getMonth();
+  if (m < 0 || (m === 0 && until.getDate() < birthDate.getDate())) {
+    age--;
+  }
+  return age;
+}