import type { TFunction } from "next-i18next";
import { useEffect, useRef } from "react";

import { useIsPlatform } from "@calcom/atoms/monorepo";
import { useIsEmbed } from "@calcom/embed-core/embed-iframe";
import { useBookerStore } from "@calcom/features/bookings/Booker/store";
import type { BookerEvent } from "@calcom/features/bookings/types";
import { classNames } from "@calcom/lib";
import { useLocale } from "@calcom/lib/hooks/useLocale";
import { useShouldShowArrows, Icon } from "@calcom/ui";

/** Render X mins as X hours or X hours Y mins instead of in minutes once >= 60 minutes */
export const getDurationFormatted = (mins: number | undefined, t: TFunction) => {
  if (!mins) return null;

  const hours = Math.floor(mins / 60);
  mins %= 60;
  // format minutes string
  let minStr = "";
  if (mins > 0) {
    minStr =
      mins === 1
        ? t("minute_one_short", { count: 1 })
        : t("multiple_duration_timeUnit_short", { count: mins, unit: "minute" });
  }
  // format hours string
  let hourStr = "";
  if (hours > 0) {
    hourStr =
      hours === 1
        ? t("hour_one_short", { count: 1 })
        : t("multiple_duration_timeUnit_short", { count: hours, unit: "hour" });
  }

  if (hourStr && minStr) return `${hourStr} ${minStr}`;
  return hourStr || minStr;
};

export const EventDuration = ({
  event,
}: {
  event: Pick<BookerEvent, "length" | "metadata" | "isDynamic">;
}) => {
  const { t } = useLocale();
  const itemRefs = useRef<(HTMLLIElement | null)[]>([]);
  const isPlatform = useIsPlatform();
  const [selectedDuration, setSelectedDuration, state] = useBookerStore((state) => [
    state.selectedDuration,
    state.setSelectedDuration,
    state.state,
  ]);

  const { ref, calculateScroll, leftVisible, rightVisible } = useShouldShowArrows();

  const handleLeft = () => {
    if (ref.current) {
      ref.current.scrollLeft -= 100;
    }
  };

  const handleRight = () => {
    if (ref.current) {
      ref.current.scrollLeft += 100;
    }
  };

  const isDynamicEvent = "isDynamic" in event && event.isDynamic;
  const isEmbed = useIsEmbed();
  // Sets initial value of selected duration to the default duration.
  useEffect(() => {
    // Only store event duration in url if event has multiple durations.
    if (!selectedDuration && (event.metadata?.multipleDuration || isDynamicEvent))
      setSelectedDuration(event.length);
  }, [selectedDuration, setSelectedDuration, event.metadata?.multipleDuration, event.length, isDynamicEvent]);

  useEffect(() => {
    const timeout = setTimeout(() => {
      if (isEmbed) return;
      if (selectedDuration && itemRefs.current[selectedDuration]) {
        // eslint-disable-next-line @calcom/eslint/no-scroll-into-view-embed -- Called on !isEmbed case
        itemRefs.current[selectedDuration]?.scrollIntoView({
          behavior: "smooth",
          block: "center",
          inline: "center",
        });
      }
    }, 100);
    return () => clearTimeout(timeout);
  }, [selectedDuration, isEmbed]);

  if (!event?.metadata?.multipleDuration && !isDynamicEvent)
    return <>{getDurationFormatted(event.length, t)}</>;

  const durations = event?.metadata?.multipleDuration || [15, 30, 60, 90];

  return selectedDuration ? (
    <div className="border-default relative mr-5 flex flex-row items-center justify-between rounded-md border">
      {leftVisible && (
        <button onClick={handleLeft} className="absolute bottom-0 left-0 flex">
          <div className="bg-default flex h-9 w-5 items-center justify-end rounded-md">
            <Icon name="chevron-left" className="text-subtle h-4 w-4" />
          </div>
          <div className="to-default flex h-9 w-5 bg-gradient-to-l from-transparent" />
        </button>
      )}
      <ul
        className="bg-default no-scrollbar flex max-w-full items-center gap-0.5 overflow-x-auto rounded-md p-1"
        onScroll={(e) => calculateScroll(e)}
        ref={ref}>
        {durations
          .filter((dur) => state !== "booking" || dur === selectedDuration)
          .map((duration, index) => (
            <li
              data-testId={`multiple-choice-${duration}mins`}
              data-active={selectedDuration === duration ? "true" : "false"}
              key={index}
              onClick={() => setSelectedDuration(duration)}
              ref={(el) => (itemRefs.current[duration] = el)}
              className={classNames(
                selectedDuration === duration ? "bg-emphasis" : "hover:text-emphasis",
                "text-default cursor-pointer rounded-[4px] px-3 py-1.5 text-sm leading-tight transition"
              )}>
              <div className="w-max">{getDurationFormatted(duration, t)}</div>
            </li>
          ))}
      </ul>
      {rightVisible && (
        <button onClick={handleRight} className="absolute bottom-0 right-0 flex">
          <div className="to-default flex h-9 w-5 bg-gradient-to-r from-transparent" />
          <div className="bg-default flex h-9 w-5 items-center justify-end rounded-md">
            <Icon name="chevron-right" className="text-subtle h-4 w-4" />
          </div>
        </button>
      )}
    </div>
  ) : null;
};