import Link from "next/link";
import { TerminStatus, TerminType, UserRole } from "@prisma/client";
import { ArrowRight, ShieldAlert } from "lucide-react";
import { Manrope } from "next/font/google";

import { requireRole } from "@/lib/auth-utils";
import { prisma } from "@/lib/prisma";
import { formatDateKey, getTargetMonthData } from "@/lib/date-utils";
import { Button } from "@/components/ui/button";
import { NotdienstEntry } from "./notdienst-entry";

export const metadata = { title: "Notdienst · Kita-Planer" };

const manrope = Manrope({
  subsets: ["latin"],
  weight: ["400", "500", "600", "700"],
});

export default async function NotdienstPage() {
  // ELTERN können eintragen; Admins/Koordinatoren haben hier eigentlich
  // andere Ansichten (Plan-Generierung), aber wir lassen sie zur Demonstration
  // ebenfalls durch, falls sie selbst Kinder haben.
  const session = await requireRole([
    UserRole.ELTERN,
    UserRole.ADMIN,
    UserRole.KOORDINATOR,
  ]);

  const kitaId = session.user.kitaId;
  if (!kitaId) {
    return <div className="p-8">Kein Mandant zugeordnet.</div>;
  }

  // Kita-Einstellungen laden
  const kita = await prisma.kita.findUniqueOrThrow({
    where: { id: kitaId },
    select: { notdienstMinPerChildPerMonth: true },
  });

  // Nur aktive Kinder des eigenen Haushalts laden.
  const children = session.user.familyId
    ? await prisma.child.findMany({
        where: {
          kitaId,
          familyId: session.user.familyId,
          active: true,
        },
        select: { id: true, firstName: true },
      })
    : [];

  const targetData = getTargetMonthData();
  const { targetYear, targetMonth, isLocked } = targetData;
  const targetMonthStart = new Date(Date.UTC(targetYear, targetMonth - 1, 1));
  const targetMonthEnd = new Date(Date.UTC(targetYear, targetMonth, 1));

  const requiredDaysTotal = children.length * kita.notdienstMinPerChildPerMonth;
  const childIds = children.map((child) => child.id);

  // Bisherige Einträge für den Zielmonat laden, haushaltsweit über die Kinder.
  const [availabilities, termine] =
    children.length > 0
      ? await Promise.all([
          prisma.notdienstAvailability.findMany({
            where: {
              kitaId,
              childId: { in: childIds },
              date: {
                gte: targetMonthStart,
                lt: targetMonthEnd,
              },
            },
            select: { date: true },
          }),
          prisma.termin.findMany({
            where: {
              kitaId,
              status: TerminStatus.CONFIRMED,
              startDate: { lt: targetMonthEnd },
              endDate: { gte: targetMonthStart },
            },
            select: {
              id: true,
              title: true,
              description: true,
              type: true,
              startDate: true,
              endDate: true,
              allDay: true,
            },
            orderBy: { startDate: "asc" },
          }),
        ])
      : [[], []];

  const selectedDates = availabilities.map((a) => formatDateKey(a.date));

  return (
    <div className={`${manrope.className} mx-auto max-w-7xl px-4 py-8 sm:px-8`}>
      {children.length === 0 ? (
        <NotdienstLockout />
      ) : (
        <NotdienstEntry
          targetYear={targetYear}
          targetMonth={targetMonth}
          isLocked={isLocked}
          requiredDaysTotal={requiredDaysTotal}
          initialSelectedDates={selectedDates}
          childrenIds={childIds}
          calendarItems={termine.map((termin) => ({
            id: termin.id,
            title: termin.title,
            category: getTerminCategory(termin.type),
            startDate: termin.startDate,
            endDate: termin.endDate,
            allDay: termin.allDay,
            note: termin.description,
          }))}
        />
      )}
    </div>
  );
}

function getTerminCategory(type: TerminType) {
  switch (type) {
    case TerminType.SCHLIESSTAG:
      return "closure" as const;
    case TerminType.TEAMTAG:
      return "team" as const;
    case TerminType.KITA_FEST:
    case TerminType.MITMACH_TAG:
      return "social" as const;
    case TerminType.ELTERNABEND:
    case TerminType.MITGLIEDERVERSAMMLUNG:
    case TerminType.ELTERNCAFE:
      return "parents" as const;
    case TerminType.GEBURTSTAG_INTERN:
    case TerminType.GEBURTSTAG_EXTERN:
      return "birthday" as const;
    default:
      return "social" as const;
  }
}

function NotdienstLockout() {
  return (
    <div className="flex min-h-[420px] items-center justify-center rounded-lg border border-dashed border-[var(--hairline)] bg-[var(--surface-2)] p-8 text-center">
      <div className="mx-auto max-w-lg">
        <div className="mx-auto flex h-20 w-20 items-center justify-center rounded-2xl bg-[var(--accent-soft)] text-[var(--accent-deep)]">
          <ShieldAlert className="h-10 w-10 [stroke-width:1.7]" />
        </div>
        <h2 className="mt-6 text-2xl font-medium tracking-[-0.02em] text-[var(--ink)]">
          Erst Kinder hinterlegen
        </h2>
        <p className="mt-3 text-sm leading-6 text-[var(--ink-soft)]">
          Bitte lege zuerst deine Kinder im Profil an, bevor du Notdienste
          übernimmst.
        </p>
        <Button asChild className="mt-6">
          <Link href="/dashboard/profil">
            Zum Profil
            <ArrowRight className="h-4 w-4" />
          </Link>
        </Button>
      </div>
    </div>
  );
}