import type { Metadata } from "next";
import { CalendarPlus, Phone } from "lucide-react";
import Link from "next/link";
import { notFound } from "next/navigation";
import { auth } from "@/auth";
import { Card } from "@/components/ui/card";
import { StatusPill } from "@/components/ui/status-pill";
import { TopNav } from "@/components/navigation/top-nav";
import { getPrimaryBusiness } from "@/lib/business/get-primary-business";
import { prisma } from "@/lib/db/prisma";
import { getAppointmentById } from "@/services/scheduling/appointment.service";
import {
  assertCanAccessAppointment,
  PermissionDeniedError,
} from "@/features/booking/authorization";
import { BookAgainButton } from "@/features/booking/components/book-again-button";
import { CancelAppointmentDialog } from "@/features/booking/components/cancel-appointment-dialog";
import type { AppointmentStatus } from "@/types/domain";

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

const STATUS_MAP: Record<string, AppointmentStatus> = {
  PENDING: "pending_approval",
  CONFIRMED: "confirmed",
  CHECKED_IN: "arrived",
  IN_PROGRESS: "in_progress",
  COMPLETED: "completed",
  CANCELLED: "cancelled",
  NO_SHOW: "no_show",
};
const RESCHEDULABLE_STATUSES = new Set(["PENDING", "CONFIRMED", "CHECKED_IN"]);
const CANCELLABLE_STATUSES = new Set(["PENDING", "CONFIRMED", "CHECKED_IN"]);
const REBOOKABLE_STATUSES = new Set(["COMPLETED", "CANCELLED", "NO_SHOW"]);

export default async function AppointmentDetailsPage({
  params,
  searchParams,
}: {
  params: Promise<{ id: string }>;
  searchParams: Promise<{ token?: string }>;
}) {
  const { id } = await params;
  const { token } = await searchParams;
  const appointment = await getAppointmentById(prisma, id);
  if (!appointment) notFound();

  const session = await auth();
  try {
    await assertCanAccessAppointment(prisma, appointment, { sessionUserId: session?.user?.id, guestToken: token });
  } catch (error) {
    if (error instanceof PermissionDeniedError) notFound(); // don't confirm the id exists to someone who can't see it
    throw error;
  }

  const business = await getPrimaryBusiness();
  const totalDuration = appointment.services.reduce(
    (sum, s) => sum + s.durationAtBookingMinutes,
    0,
  );
  const totalPrice = appointment.services.reduce((sum, s) => sum + Number(s.priceAtBooking), 0);
  let cancelledByLabel: string | null = null;
  if (appointment.status === "CANCELLED" && appointment.cancelledByUserId) {
    const canceller = await prisma.user.findUnique({
      where: { id: appointment.cancelledByUserId },
      select: { name: true },
    });
    cancelledByLabel = canceller?.name ?? null;
  }

  return (
    <div className="pb-12">
      <TopNav title="Appointment Details" onBack={true} sticky className="bg-stone" />

      <main className="mx-auto max-w-2xl space-y-4 px-6 py-6">
        <Card className="space-y-6 p-6">
          <div className="flex items-center justify-between">
            <StatusPill status={STATUS_MAP[appointment.status] ?? "confirmed"} />
            <span className="text-muted text-[10px] font-bold tracking-widest uppercase">
              Ref: {appointment.id.slice(-8)}
            </span>
          </div>

          <div className="border-line space-y-1 border-t pt-4">
            <p className="text-lg font-bold">
              {appointment.services.map((s) => s.service.name).join(" + ")}
            </p>
            <p className="text-muted text-sm">
              with {appointment.staff.user.name} · {business.name}
            </p>
          </div>

          <div className="border-line grid grid-cols-2 gap-4 border-t pt-4 text-sm">
            <div>
              <span className="text-muted block text-[10px] font-bold tracking-widest uppercase">
                Date
              </span>
              {appointment.startAt.toLocaleDateString("en-GB", {
                weekday: "short",
                day: "numeric",
                month: "short",
                timeZone: business.timezone,
              })}
            </div>
            <div>
              <span className="text-muted block text-[10px] font-bold tracking-widest uppercase">
                Time
              </span>
              {appointment.startAt.toLocaleTimeString("en-GB", {
                hour: "2-digit",
                minute: "2-digit",
                timeZone: business.timezone,
              })}
            </div>
            <div>
              <span className="text-muted block text-[10px] font-bold tracking-widest uppercase">
                Duration
              </span>
              {totalDuration} min
            </div>
            <div>
              <span className="text-muted block text-[10px] font-bold tracking-widest uppercase">
                Total
              </span>
              £{totalPrice.toFixed(2)}
            </div>
          </div>

          {appointment.notes && (
            <div className="border-line border-t pt-4">
              <span className="text-muted block text-[10px] font-bold tracking-widest uppercase">
                Your Notes
              </span>
              <p className="text-muted mt-1 text-sm italic">{appointment.notes}</p>
            </div>
          )}

          {appointment.status === "CANCELLED" && (
            <div className="border-line border-t pt-4 text-sm">
              <span className="text-muted block text-[10px] font-bold tracking-widest uppercase">
                Cancellation
              </span>
              <p className="text-muted mt-1">
                Cancelled{" "}
                {appointment.cancelledAt?.toLocaleString("en-GB", { timeZone: business.timezone })}
                {cancelledByLabel ? ` by ${cancelledByLabel}` : ""}
              </p>
              {appointment.cancellationReason && (
                <p className="text-muted mt-1 italic">
                  &ldquo;{appointment.cancellationReason}&rdquo;
                </p>
              )}
            </div>
          )}
        </Card>

        <div className="flex flex-col gap-3">
          <a
            href={`/api/appointments/${appointment.id}/calendar.ics${token ? `?token=${token}` : ""}`}
            className="rounded-md border-line flex w-full items-center justify-center gap-2 border bg-white px-5 py-3 text-sm font-bold"
          >
            <CalendarPlus className="text-accent h-4 w-4" aria-hidden="true" /> Add to Calendar
          </a>
          {business.phone && (
            <a
              href={`tel:${business.phone}`}
              className="rounded-md border-line flex w-full items-center justify-center gap-2 border bg-white px-5 py-3 text-sm font-bold"
            >
              <Phone className="text-accent h-4 w-4" aria-hidden="true" /> Contact Business
            </a>
          )}
          {RESCHEDULABLE_STATUSES.has(appointment.status) && (
            <Link
              href={`/appointments/${appointment.id}/reschedule${token ? `?token=${token}` : ""}`}
              className="rounded-md border-line block w-full border bg-white px-5 py-3 text-center text-sm font-bold"
            >
              Reschedule
            </Link>
          )}
          {CANCELLABLE_STATUSES.has(appointment.status) && (
            <CancelAppointmentDialog appointmentId={appointment.id} guestToken={token} className="w-full" />
          )}
          {REBOOKABLE_STATUSES.has(appointment.status) && (
            <BookAgainButton appointmentId={appointment.id} guestToken={token} className="w-full" />
          )}
        </div>
      </main>
    </div>
  );
}