import { useEffect, useMemo, useState } from "react";
import { useLocation, useNavigate, useParams } from "react-router-dom";
import Icon from "../components/Icon";
import { CafeEvent, mockCafeEvents } from "../data/mockCafeEvents";
import { EventReservation, fetchEventReservations } from "../services/campaignApi";
import { getCafeUuid } from "../utils/cafe";
import HostBanner from "../assets/images/banners/Host-banner.jpg";
import { formatPersianNumber } from "../utils/formatNumber";

function toEnglishDigits(value: string) {
  const persianDigits = "۰۱۲۳۴۵۶۷۸۹";
  return value.replace(/[۰-۹]/g, (digit) =>
    String(persianDigits.indexOf(digit)),
  );
}

function reservationMatches(reservation: EventReservation, query: string) {
  if (!query) return true;
  const haystack = toEnglishDigits(
    `${reservation.full_name} ${reservation.phone_number} ${reservation.people_count} ${formatPersianNumber(reservation.people_count)} ${reservation.reserve_code}`,
  ).toLowerCase();
  return haystack.includes(toEnglishDigits(query).toLowerCase());
}

function downloadReservationsCsv(reservations: EventReservation[]) {
  const header = ["کد رزرو", "تعداد", "نام", "شماره تماس"];
  const rows = reservations.map((r) => [
    r.reserve_code,
    String(r.people_count),
    r.full_name,
    toEnglishDigits(r.phone_number),
  ]);
  const csvContent = [header, ...rows]
    .map((row) => row.map((cell) => `"${cell.replace(/"/g, '""')}"`).join(","))
    .join("\n");

  const blob = new Blob(["" + csvContent], {
    type: "text/csv;charset=utf-8;",
  });
  const url = URL.createObjectURL(blob);
  const link = document.createElement("a");
  link.href = url;
  link.download = "reservations.csv";
  link.click();
  URL.revokeObjectURL(url);
}

function ReservationCard({
  reservation,
  selected,
  onToggle,
}: {
  reservation: EventReservation;
  selected: boolean;
  onToggle: () => void;
}) {
  return (
    <div className="flex items-center justify-between rounded-2xl shadow-[0px_4px_12px_0px_#0000001F] p-6">
      <div className="flex flex-col items-start gap-2 text-right">
        <div className="flex items-center gap-2">
          <span className="font-medium rounded-full bg-[#ECF2F8] px-3 py-1 text-sm text-gray-700 h-9 flex items-center">
            {reservation.reserve_code}
          </span>
          <span className="font-medium rounded-full bg-[#ECF2F8] px-3 py-1 text-sm text-gray-700 h-9 flex items-center">
            {formatPersianNumber(reservation.people_count)} نفر
          </span>
        </div>
        <p className="text-gray-900">{reservation.full_name}</p>
        <p className="text-gray-500">{reservation.phone_number}</p>
      </div>
      <button
        type="button"
        onClick={onToggle}
        className={`flex h-6 w-6 shrink-0 items-center justify-center rounded-md border-2 border-[#223D5D] ${selected ? "bg-[#223D5D]" : "bg-transparent"}`}
      >
        {selected && <Icon name="check" className="h-3 w-3 text-white" />}
      </button>
    </div>
  );
}

export default function EventReservations() {
  const { id } = useParams();
  const location = useLocation();
  const navigate = useNavigate();
  const [query, setQuery] = useState("");
  const [selectedIds, setSelectedIds] = useState<string[]>([]);
  const [reservations, setReservations] = useState<EventReservation[]>([]);

  const event: CafeEvent | undefined =
    (location.state as { event?: CafeEvent } | null)?.event ??
    mockCafeEvents.find((e) => e.id === Number(id));

  useEffect(() => {
    const cafeUuid = getCafeUuid();
    if (!cafeUuid || !id) return;
    fetchEventReservations(cafeUuid, id)
      .then(setReservations)
      .catch(() => {});
  }, [id]);

  const filteredReservations = useMemo(
    () =>
      reservations.filter((reservation) =>
        reservationMatches(reservation, query),
      ),
    [reservations, query],
  );

  const toggleSelected = (reservationId: string) => {
    setSelectedIds((prev) =>
      prev.includes(reservationId)
        ? prev.filter((id) => id !== reservationId)
        : [...prev, reservationId],
    );
  };

  const handleDownload = () => {
    downloadReservationsCsv(reservations);
  };

  return (
    <div className="min-h-screen bg-white pb-24">
      <img src={HostBanner} alt="" className="w-full" />

      <button
        type="button"
        onClick={() => navigate(-1)}
        className="mt-4 flex w-full items-center justify-start gap-2 px-4"
      >
        <Icon name="arrowRight" className="h-5 w-5 -scale-x-100 text-gray-900" />
        <span className="text-md font-semibold text-gray-900">
          رزروهای {event?.matchLabel ?? ""}
        </span>
      </button>

      <div className="relative mt-4 px-4">
        <input
          type="text"
          value={query}
          onChange={(e) => setQuery(e.target.value)}
          placeholder="جستجو"
          className="w-full rounded-2xl shadow-[0px_4px_12px_0px_#0000001F] bg-white py-3 pr-6 pl-4 text-right placeholder:font-light placeholder:text-[#999999]"
        />
        <Icon
          name="search"
          className="pointer-events-none absolute left-8 top-1/2 h-5 w-5 -translate-y-1/2 text-[#666666]"
        />
      </div>

      <div className="mt-4 flex flex-col gap-3 px-4">
        {filteredReservations.map((reservation) => (
          <ReservationCard
            key={reservation.uuid}
            reservation={reservation}
            selected={selectedIds.includes(reservation.uuid)}
            onToggle={() => toggleSelected(reservation.uuid)}
          />
        ))}
      </div>

      <div className="fixed inset-x-0 bottom-0 bg-white px-4 py-4">
        <button
          type="button"
          onClick={handleDownload}
          className="w-full rounded-2xl bg-[#223D5D] py-4 text-lg font-semibold text-white"
        >
          دانلود لیست
        </button>
      </div>
    </div>
  );
}