/**
 * Admin page: list duties for the month and reassign duty to another user.
 * Visible only to admins (link shown on calendar when GET /api/admin/me returns is_admin).
 * Logic and heavy UI live in components/admin (useAdminPage, AdminDutyList, ReassignSheet).
 */

"use client";

import { useAdminPage, AdminDutyList, ReassignSheet } from "@/components/admin";
import { useTranslation } from "@/i18n/use-translation";
import { MonthNavHeader } from "@/components/calendar/MonthNavHeader";
import { AccessDeniedScreen } from "@/components/states/AccessDeniedScreen";
import { LoadingState } from "@/components/states/LoadingState";
import { ErrorState } from "@/components/states/ErrorState";
import { MiniAppScreen, MiniAppScreenContent, MiniAppStickyHeader } from "@/components/layout/MiniAppScreen";
import { useScreenReady } from "@/hooks/use-screen-ready";

export default function AdminPage() {
  const { t, monthName } = useTranslation();
  const admin = useAdminPage();
  useScreenReady(true);

  if (!admin.isAllowed) {
    return (
      <MiniAppScreen>
        <MiniAppScreenContent>
          <AccessDeniedScreen primaryAction="reload" />
        </MiniAppScreenContent>
      </MiniAppScreen>
    );
  }

  if (admin.adminCheckComplete === null) {
    return (
      <MiniAppScreen>
        <MiniAppScreenContent>
        <div className="py-4 flex flex-col items-center gap-2">
          <LoadingState />
          <p className="text-sm text-muted-foreground">{t("admin.loading_users")}</p>
        </div>
        </MiniAppScreenContent>
      </MiniAppScreen>
    );
  }

  if (admin.adminAccessDenied) {
    return (
      <MiniAppScreen>
        <MiniAppScreenContent>
        <div className="flex flex-col gap-4 py-6">
          <p className="text-muted-foreground">
            {admin.adminAccessDeniedDetail ?? t("admin.access_denied")}
          </p>
        </div>
        </MiniAppScreenContent>
      </MiniAppScreen>
    );
  }

  const month = admin.adminMonth.getMonth();
  const year = admin.adminMonth.getFullYear();

  return (
    <MiniAppScreen>
      <MiniAppScreenContent>
      <MiniAppStickyHeader className="flex flex-col items-center border-b border-border py-3">
        <MonthNavHeader
          month={admin.adminMonth}
          disabled={admin.loading}
          onPrevMonth={admin.onPrevMonth}
          onNextMonth={admin.onNextMonth}
          titleAriaLabel={`${t("admin.title")}, ${monthName(month)} ${year}`}
          className="w-full px-1"
        />
      </MiniAppStickyHeader>

      {admin.successMessage && (
        <p className="mt-3 text-sm text-[var(--duty)]" role="status" aria-live="polite">
          {admin.successMessage}
        </p>
      )}

      {admin.loading && (
        <div className="py-4 flex flex-col items-center gap-2">
          <LoadingState />
          <p className="text-sm text-muted-foreground">{t("admin.loading_users")}</p>
        </div>
      )}

      {admin.error && !admin.loading && (
        <ErrorState
          message={admin.error}
          onRetry={() => window.location.reload()}
          className="my-3"
        />
      )}

      {!admin.loading && !admin.error && (
        <div className="mt-3 flex flex-col gap-2">
          {admin.visibleGroups.length > 0 && (
            <p className="text-sm text-muted-foreground">
              {t("admin.reassign_duty")}: {t("admin.select_user")}
            </p>
          )}
          <AdminDutyList
            groups={admin.visibleGroups}
            hasMore={admin.hasMore}
            sentinelRef={admin.sentinelRef}
            onSelectDuty={admin.openReassign}
            t={t}
          />
        </div>
      )}

      <ReassignSheet
        open={!admin.sheetExiting && admin.selectedDuty !== null}
        selectedDuty={admin.selectedDuty}
        selectedUserId={admin.selectedUserId}
        setSelectedUserId={admin.setSelectedUserId}
        users={admin.usersForSelect}
        saving={admin.saving}
        reassignErrorKey={admin.reassignErrorKey}
        onReassign={admin.handleReassign}
        onRequestClose={admin.requestCloseSheet}
        onCloseAnimationEnd={admin.closeReassign}
        t={t}
      />
      </MiniAppScreenContent>
    </MiniAppScreen>
  );
}