P combobox 16

"use client";

import { useMemo } from "react";
import {
  Combobox,
  ComboboxEmpty,
  ComboboxInput,
  ComboboxItem,
  ComboboxList,
  ComboboxPopup,
} from "@/registry/default/ui/combobox";

export default function Particle() {
  const timezones = Intl.supportedValuesOf("timeZone");

  const formattedTimezones = useMemo(() => {
    return timezones
      .map((timezone) => {
        const formatter = new Intl.DateTimeFormat("en", {
          timeZone: timezone,
          timeZoneName: "shortOffset",
        });
        const parts = formatter.formatToParts(new Date());
        const offset =
          parts.find((part) => part.type === "timeZoneName")?.value || "";
        const modifiedOffset = offset === "GMT" ? "GMT+0" : offset;

        const offsetMatch = offset.match(/GMT([+-]?)(\d+)(?::(\d+))?/);
        const sign = offsetMatch?.[1] === "-" ? -1 : 1;
        const hours = Number.parseInt(offsetMatch?.[2] || "0", 10);
        const minutes = Number.parseInt(offsetMatch?.[3] || "0", 10);
        const totalMinutes = sign * (hours * 60 + minutes);

        return {
          label: `(${modifiedOffset}) ${timezone.replace(/_/g, " ")}`,
          numericOffset: totalMinutes,
          value: timezone,
        };
      })
      .sort((a, b) => a.numericOffset - b.numericOffset);
  }, [timezones]);

  const defaultTimezone = formattedTimezones.find(
    (tz) => tz.value === "Europe/London",
  );

  return (
    <Combobox
      autoHighlight
      defaultValue={defaultTimezone}
      items={formattedTimezones}
    >
      <ComboboxInput
        aria-label="Select timezone"
        placeholder="Select timezone..."
      />
      <ComboboxPopup>
        <ComboboxEmpty>No timezones found.</ComboboxEmpty>
        <ComboboxList>
          {(item) => (
            <ComboboxItem key={item.value} value={item}>
              {item.label}
            </ComboboxItem>
          )}
        </ComboboxList>
      </ComboboxPopup>
    </Combobox>
  );
}