import type { Metadata } from "next";
import { Plus, Search, Upload, Users } from "lucide-react";
import Link from "next/link";
import { redirect } from "next/navigation";
import { EmptyState } from "@/components/feedback/empty-state";
import { TopNav } from "@/components/navigation/top-nav";
import { Permission } from "@/generated/prisma/enums";
import { hasPermission } from "@/lib/auth/permissions";
import { prisma } from "@/lib/db/prisma";
import { getActingBusinessContext } from "@/lib/business/get-acting-business-context";
import { getUnreadNotificationCount } from "@/services/notifications/notification.service";
import { clientDirectoryWhere } from "@/services/customer/client-directory";
import { matchesCustomerSearch } from "@/services/customer/customer.service";
import { getLoyaltySummariesForCustomers } from "@/services/loyalty/loyalty.service";
import { NoShowBadge } from "@/features/staff/components/no-show-badge";
import { countNoShows, evaluateStanding, getNoShowThresholds } from "@/services/customer/no-show.service";
import { InlineNotificationBell } from "@/features/notifications/components/notification-bell";
import { cn } from "@/lib/utils/cn";

export const metadata: Metadata = { title: "Clients" };
export const dynamic = "force-dynamic";

const UPCOMING_STATUSES = ["PENDING", "CONFIRMED", "CHECKED_IN"];

export default async function StaffClientsPage({
  searchParams,
}: {
  searchParams: Promise<{ q?: string; sort?: string }>;
}) {
  const context = await getActingBusinessContext();
  if (!context) redirect("/home");

  const { q = "", sort } = await searchParams;

  const [unreadNotificationCount, canImport] = await Promise.all([
    getUnreadNotificationCount(prisma, context.userId),
    hasPermission(context.userId, Permission.MANAGE_BUSINESS_PROFILE),
  ]);

  // Who counts as a client is defined once, in clientDirectoryWhere (shared with
  // the detail page so the two can't disagree). `select`-scoped rather than a
  // full row + appointment `include`: the card only ever reads status/startAt
  // off each appointment, never the service lines/notes/discount a full
  // include would pull down for every appointment of every client on every
  // page view (see the Phase 7 performance pass).
  const customers = await prisma.customerProfile.findMany({
    where: clientDirectoryWhere(context.businessId),
    select: {
      id: true,
      firstName: true,
      lastName: true,
      email: true,
      phone: true,
      noShowResetAt: true,
      appointments: {
        where: { businessId: context.businessId },
        orderBy: { startAt: "desc" },
        select: { status: true, startAt: true },
      },
    },
  });

  const noShowThresholds = await getNoShowThresholds(prisma, context.businessId);

  const loyaltySummaries = await getLoyaltySummariesForCustomers(prisma, {
    businessId: context.businessId,
    customerIds: customers.map((c) => c.id),
  });

  const filtered = customers.filter((c) => matchesCustomerSearch(c, q));

  const sorted = [...filtered].sort((a, b) => {
    if (sort === "recent") {
      const aLatest = a.appointments[0]?.startAt.getTime() ?? 0;
      const bLatest = b.appointments[0]?.startAt.getTime() ?? 0;
      return bLatest - aLatest;
    }
    return `${a.lastName} ${a.firstName}`.localeCompare(`${b.lastName} ${b.firstName}`);
  });

  const now = new Date();

  return (
    <div className="pb-8">
      <TopNav
        title="Clients"
        sticky
        className="bg-stone"
        leftAction={<InlineNotificationBell href="/staff/notifications" unreadCount={unreadNotificationCount} />}
        action={
          <div className="flex gap-2">
            {canImport && (
              <Link
                href="/staff/clients/import"
                className="border-line flex h-10 w-10 items-center justify-center rounded-full border bg-white"
                aria-label="Import clients from a spreadsheet"
              >
                <Upload className="h-4 w-4" aria-hidden="true" />
              </Link>
            )}
            <Link
              href="/staff/clients/add"
              className="bg-ink flex h-10 w-10 items-center justify-center rounded-full text-white"
              aria-label="Add client"
            >
              <Plus className="h-4 w-4" aria-hidden="true" />
            </Link>
          </div>
        }
      />

      <div className="px-6 pt-6">
        <form action="/staff/clients" method="GET" className="relative mb-4">
          {sort && <input type="hidden" name="sort" value={sort} />}
          <Search
            className="text-muted absolute top-1/2 left-4 h-4 w-4 -translate-y-1/2"
            aria-hidden="true"
          />
          <label htmlFor="client-search" className="sr-only">
            Search clients by name, email, or phone
          </label>
          <input
            id="client-search"
            type="search"
            name="q"
            defaultValue={q}
            placeholder="Search by name, email, or phone"
            className="border-line focus:ring-ink w-full rounded-xl border bg-white py-3 pr-4 pl-11 text-sm outline-none focus:ring-2"
          />
        </form>

        <div className="mb-4 flex gap-2">
          <Link
            href={`/staff/clients?q=${encodeURIComponent(q)}&sort=name`}
            className={cn(
              "rounded-full px-4 py-1.5 text-xs font-bold tracking-widest uppercase",
              sort !== "recent" ? "bg-ink text-white" : "border-line text-muted border bg-white",
            )}
          >
            Alphabetical
          </Link>
          <Link
            href={`/staff/clients?q=${encodeURIComponent(q)}&sort=recent`}
            className={cn(
              "rounded-full px-4 py-1.5 text-xs font-bold tracking-widest uppercase",
              sort === "recent" ? "bg-ink text-white" : "border-line text-muted border bg-white",
            )}
          >
            Recent
          </Link>
        </div>

        {sorted.length === 0 ? (
          <EmptyState
            icon={Users}
            title={q ? "No matching clients" : "No clients yet"}
            description={
              q
                ? "Try a different name, email, or phone number."
                : "Clients will show up here once they've booked with you."
            }
          />
        ) : (
          <div className="grid gap-3 lg:grid-cols-2 xl:grid-cols-3 2xl:grid-cols-4">
            {sorted.map((customer) => {
              const completedVisits = customer.appointments.filter(
                (a) => a.status === "COMPLETED",
              ).length;
              const lastVisit = customer.appointments.find((a) => a.status === "COMPLETED");
              const upcoming = customer.appointments.find(
                (a) => UPCOMING_STATUSES.includes(a.status) && a.startAt > now,
              );
              const loyalty = loyaltySummaries.get(customer.id);
              const noShow = evaluateStanding(
                countNoShows(customer.appointments, customer.noShowResetAt),
                noShowThresholds,
              );

              return (
                <Link
                  key={customer.id}
                  href={`/staff/clients/${customer.id}`}
                  className="rounded-md border-line hover:bg-stone flex items-center gap-3 border bg-white px-5 py-4"
                >
                  <div className="bg-stone text-muted flex h-11 w-11 shrink-0 items-center justify-center rounded-full text-sm font-bold">
                    {customer.firstName.charAt(0)}
                    {customer.lastName.charAt(0)}
                  </div>
                  <div className="min-w-0 flex-1">
                    <p className="flex items-center gap-2 text-sm font-bold">
                      <span className="truncate">
                        {customer.firstName} {customer.lastName}
                      </span>
                      <NoShowBadge count={noShow.count} flagged={noShow.flagged} blocked={noShow.blocked} />
                    </p>
                    <p className="text-muted truncate text-xs">
                      {customer.phone ?? customer.email}
                      {lastVisit &&
                        ` · Last visit ${lastVisit.startAt.toLocaleDateString("en-GB", { day: "numeric", month: "short" })}`}
                    </p>
                    <p className="text-muted mt-0.5 text-[10px] font-bold tracking-widest uppercase">
                      {completedVisits} visit{completedVisits === 1 ? "" : "s"}
                      {upcoming && <span className="text-accent"> · Upcoming</span>}
                      {loyalty && (
                        <span className={loyalty.hasAvailableReward ? "text-accent-loyalty" : ""}>
                          {" "}
                          · {loyalty.currentStamps}/{loyalty.rewardThreshold} stamps
                        </span>
                      )}
                    </p>
                  </div>
                </Link>
              );
            })}
          </div>
        )}
      </div>
    </div>
  );
}