import { useEffect, useState } from "react";
import { Link, useSearchParams } from "react-router-dom";
import { useTranslation } from "react-i18next";
import { api } from "../api/client";
import type { Page, Vehicle } from "../api/types";
import { useLocaleFormat } from "../i18n/format";
import { StatusBadge } from "../components/Badge";
import { EmptyState, ErrorState, LoadingState, PageHeader } from "../components/PageChrome";
import { Pagination } from "../components/Pagination";

const STATUS_OPTIONS = ["available", "rented", "cleaning", "maintenance", "blocked"];

export function Vehicles() {
  const { t } = useTranslation("fleet");
  const { formatDateTime, formatNumber } = useLocaleFormat();
  const [searchParams, setSearchParams] = useSearchParams();
  const [vehicles, setVehicles] = useState<Page<Vehicle> | null>(null);
  const [error, setError] = useState<string | null>(null);
  const status = searchParams.get("status") ?? "";
  const attentionOnly = searchParams.get("attention_only") === "true";
  const query = searchParams.get("q") ?? "";
  const location = searchParams.get("location") ?? "";
  const page = Math.max(1, Number(searchParams.get("page") ?? "1") || 1);

  function updateFilters(updates: Record<string, string | boolean | number | null>) {
    const next = new URLSearchParams(searchParams);
    Object.entries(updates).forEach(([key, value]) => {
      if (value === null || value === "" || value === false) next.delete(key);
      else next.set(key, String(value));
    });
    setSearchParams(next, { replace: true });
  }

  useEffect(() => {
    setVehicles(null);
    setError(null);
    const params = new URLSearchParams();
    if (status) params.set("status", status);
    if (attentionOnly) params.set("attention_only", "true");
    if (query) params.set("query", query);
    if (location) params.set("location", location);
    params.set("page", String(page));
    params.set("page_size", "25");
    const controller = new AbortController();
    api
      .get<Page<Vehicle>>(`/api/v1/vehicles?${params.toString()}`, { signal: controller.signal })
      .then(setVehicles)
      .catch(() => {
        if (!controller.signal.aborted) setError(t("list.unavailable"));
      });
    return () => controller.abort();
  }, [status, attentionOnly, query, location, page, t]);

  return (
    <div className="page">
      <PageHeader eyebrow={t("list.eyebrow")} title={t("list.title")} description={t("list.description")} />

      <form className="filters" aria-label={t("list.title")}>
        <label>
          {t("list.searchLabel")}
          <input type="search" value={query} onChange={(e) => updateFilters({ q: e.target.value, page: 1 })} placeholder={t("list.searchPlaceholder")} />
        </label>
        <label>
          {t("list.statusLabel")}
          <select value={status} onChange={(e) => updateFilters({ status: e.target.value, page: 1 })}>
            <option value="">{t("list.statusAll")}</option>
            {STATUS_OPTIONS.map((s) => (
              <option key={s} value={s}>
                {t(`statuses.${s}`)}
              </option>
            ))}
          </select>
        </label>
        <label className="checkbox-label">
          <input
            type="checkbox"
            checked={attentionOnly}
            onChange={(e) => updateFilters({ attention_only: e.target.checked, page: 1 })}
          />
          {t("list.attentionOnly")}
        </label>
        <label>{t("list.locationFilter")}<input value={location} onChange={(event) => updateFilters({ location: event.target.value, page: 1 })} placeholder={t("list.locationPlaceholder")} /></label>
      </form>

      {error && <ErrorState message={error} />}
      {!error && !vehicles && <LoadingState label={t("list.loading")} />}
      {vehicles && vehicles.items.length === 0 && <EmptyState icon={query ? "search" : "fleet"} title={query ? t("list.noMatch") : t("list.empty")} detail={query ? t("list.noMatchDetail") : t("list.emptyDetail")} />}

      {vehicles && vehicles.items.length > 0 && <div className="table-shell"><div className="table-meta"><span>{t("list.count", { count: vehicles.total })}</span><span>{t("list.persisted")}</span></div><table className="data-table">
          <caption className="visually-hidden">{t("list.title")}</caption>
          <thead>
            <tr>
              <th scope="col">{t("list.columns.reference")}</th>
              <th scope="col">{t("list.columns.makeModel")}</th>
              <th scope="col">{t("list.columns.location")}</th>
              <th scope="col">{t("list.columns.status")}</th>
              <th scope="col">{t("list.columns.odometer")}</th>
              <th scope="col">{t("list.columns.service")}</th>
              <th scope="col">{t("list.columns.nextBooking")}</th>
              <th scope="col">{t("list.columns.attention")}</th>
            </tr>
          </thead>
          <tbody>
            {vehicles.items.map((v) => (
              <tr key={v.public_ref} className={`row-clickable ${v.attention ? "row-attention" : ""}`}>
                <th scope="row" data-label={t("list.columns.reference")}>
                  {v.public_ref}
                  <Link className="row-link" to={`/vehicles/${v.public_ref}`}><span className="visually-hidden">{v.public_ref}</span></Link>
                </th>
                <td data-label={t("list.columns.makeModel")}>
                  {v.make} {v.model} ({v.model_year})
                </td>
                <td data-label={t("list.columns.location")}>{v.location}</td>
                <td data-label={t("list.columns.status")}>
                  <StatusBadge status={v.operational_status} label={t(`statuses.${v.operational_status}`, { defaultValue: v.operational_status })} />
                </td>
                <td data-label={t("list.columns.odometer")}>{formatNumber(v.odometer_km)}</td>
                <td data-label={t("list.columns.service")} className={v.service_remaining_km <= 0 ? "is-overdue" : ""}>{v.service_remaining_km <= 0 ? t("list.serviceDue") : t("list.serviceRemaining", { count: formatNumber(v.service_remaining_km) })}</td>
                <td data-label={t("list.columns.nextBooking")}>{v.next_booking_ref && v.next_booking_at ? <Link className="cell-link" to={`/bookings/${v.next_booking_ref}`}>{v.next_booking_ref}<span className="table-secondary">{formatDateTime(v.next_booking_at)}</span></Link> : "—"}</td>
                <td data-label={t("list.columns.attention")}>{v.attention && v.attention_reason ? <span className="attention-flag">{t(`list.attentionReasons.${v.attention_reason}`)}</span> : "—"}</td>
              </tr>
            ))}
          </tbody>
        </table><Pagination page={vehicles.page} totalPages={vehicles.total_pages} onPageChange={(nextPage) => updateFilters({ page: nextPage })} /></div>}
    </div>
  );
}