import type { Metadata } from "next";
import { noticeUrl } from "@/lib/notice";
import { noIndexPrivate } from "@/lib/seo";
import { notFound, redirect } from "next/navigation";
import { Container } from "@/components/ui";
import { BackLink } from "@/components/back-link";
import { getCurrentCustomer } from "@/lib/auth";
import { getInvoiceForCustomer } from "@/lib/account-data";
import { formatPrice, formatDate } from "@/lib/format";
import { getCompanyInfo } from "@/lib/company-info";
import { invoiceVatBreakdown } from "@/lib/vat";
import { getLocale } from "@/i18n/locale";
import { getDictionary } from "@/i18n/get-dictionary";

// Rechnungen enthalten Name, Anschrift und Kaufhistorie. noIndexPrivate
// unterbindet zusaetzlich Cache-Kopie und Snippet (siehe lib/seo.ts).
export const metadata: Metadata = { title: "Rechnung", robots: noIndexPrivate };
export const dynamic = "force-dynamic";

export default async function InvoicePage(props: PageProps<"/rechnung/[invoiceNumber]">) {
  const t = getDictionary(await getLocale());
  const { invoiceNumber } = await props.params;
  const customer = await getCurrentCustomer();
  if (!customer) redirect(noticeUrl("invoice-login"));

  const invoice = await getInvoiceForCustomer(invoiceNumber, customer.id);
  if (!invoice) notFound();

  const { order } = invoice;
  const company = await getCompanyInfo();
  // Aufstellung je Steuersatz — eine Bestellung kann Honig (ermaessigt) und
  // eine Bienenwachskerze (voll) zugleich enthalten. Dieselbe Funktion nutzt
  // das PDF, damit beide Darstellungen desselben Belegs uebereinstimmen.
  const vatLines = invoiceVatBreakdown(order);
  const isSmallBusiness = vatLines.length > 0 && vatLines.every((line) => line.ratePercent === 0);

  return (
    <div className="py-16 print:py-0">
      <Container className="max-w-2xl">
        <div className="print:hidden flex items-center justify-between">
          <BackLink href="/konto/bestellungen" label={t.invoicePage.backToOrders} />
          <a
            href={`/rechnung/${invoice.invoiceNumber}/pdf`}
            className="mb-6 text-sm text-heading underline"
          >
            {t.invoicePage.downloadPdf}
          </a>
        </div>
        <div className="flex justify-between items-start">
          <div>
            <p className="text-2xl tracking-[0.2em] font-serif text-heading">{company.name.toUpperCase()}</p>
            <p className="mt-2 text-sm text-ink/70">
              {company.address.street}
              <br />
              {company.address.zip} {company.address.city}
            </p>
          </div>
          <div className="text-right text-sm text-ink/70">
            <p className="text-heading">{t.invoicePage.invoiceLabel(invoice.invoiceNumber)}</p>
            <p>{t.invoicePage.orderLabel(order.orderNumber)}</p>
            <p>{formatDate(invoice.issuedAt)}</p>
          </div>
        </div>

        <div className="mt-10 text-sm text-ink/75">
          <p>{order.firstName} {order.lastName}</p>
          <p>{order.street}</p>
          <p>{order.zip} {order.city}</p>
        </div>

        <table className="mt-10 w-full text-sm">
          <thead className="text-left text-ink/65 border-b border-ink/10">
            <tr>
              <th className="py-2">{t.invoicePage.itemHeader}</th>
              <th className="py-2 text-right">{t.invoicePage.quantityHeader}</th>
              <th className="py-2 text-right">{t.invoicePage.priceHeader}</th>
              <th className="py-2 text-right">{t.invoicePage.totalHeader}</th>
            </tr>
          </thead>
          <tbody className="divide-y divide-ink/10">
            {order.items.map((item) => (
              <tr key={item.id}>
                <td className="py-2">{item.productName} ({item.weightGrams} g)</td>
                <td className="py-2 text-right">{item.quantity}</td>
                <td className="py-2 text-right">{formatPrice(item.unitPriceCents)}</td>
                <td className="py-2 text-right">{formatPrice(item.totalCents)}</td>
              </tr>
            ))}
          </tbody>
        </table>

        <div className="mt-6 flex justify-end">
          <div className="w-56 space-y-2 text-sm">
            <div className="flex justify-between">
              <span className="text-ink/70">{t.invoicePage.subtotalLabel}</span>
              <span>{formatPrice(order.subtotalCents, order.currency)}</span>
            </div>
            <div className="flex justify-between">
              <span className="text-ink/70">{t.invoicePage.shippingLabel}</span>
              <span>
                {order.shippingCents === 0 ? t.invoicePage.freeShipping : formatPrice(order.shippingCents, order.currency)}
              </span>
            </div>
            {order.discountCents > 0 ? (
              <div className="flex justify-between">
                <span className="text-ink/70">
                  {t.invoicePage.discountLabel}{order.discountCode ? ` (${order.discountCode.code})` : ""}
                </span>
                <span>−{formatPrice(order.discountCents, order.currency)}</span>
              </div>
            ) : null}
            {/* Steuerausweis mit demselben an der Rechnung festgeschriebenen
                Satz wie im PDF — beide Darstellungen desselben Belegs muessen
                uebereinstimmen. */}
            {vatLines
              .filter((line) => line.ratePercent > 0)
              .map((line) => (
                <div key={line.ratePercent}>
                  <div className="flex justify-between">
                    <span className="text-ink/70">{t.invoicePage.netLabel}</span>
                    <span>{formatPrice(line.netCents, order.currency)}</span>
                  </div>
                  <div className="flex justify-between">
                    <span className="text-ink/70">{t.invoicePage.vatLabel(line.ratePercent)}</span>
                    <span>{formatPrice(line.vatCents, order.currency)}</span>
                  </div>
                </div>
              ))}
            <div className="flex justify-between text-heading pt-2 border-t border-ink/10">
              <span>{t.invoicePage.totalLabel}</span>
              <span>{formatPrice(invoice.totalCents, order.currency)}</span>
            </div>
            {/* Pflichtangabe bei Kleinunternehmerregelung — steht anstelle der
                Steuerzeilen, nicht zusaetzlich. */}
            {isSmallBusiness ? (
              <p className="pt-2 text-xs text-ink/65">{t.invoicePage.smallBusinessNote}</p>
            ) : null}
          </div>
        </div>

        <p className="mt-16 text-xs text-ink/65">{t.invoicePage.legalNote}</p>
      </Container>
    </div>
  );
}