import { useTranslations, useFormatter } from "next-intl";
import { Card } from "@/components/ui/card";
import type { Invoice, InvoiceLine } from "@/types";
import { PayInvoiceButton } from "./pay-invoice-button";
import { PaymentStatusBanner } from "./payment-status-banner";

interface Props {
  invoice: Invoice;
  lines: InvoiceLine[];
}

const statusColors: Record<string, string> = {
  open: "text-text-secondary bg-surface-3",
  paid: "text-success bg-success/10",
  overdue: "text-error bg-error/10",
  void: "text-text-muted bg-surface-3",
};

/**
 * Read-only invoice detail. Flat list of lines — no per-tenant
 * grouping (one invoice per customer; the tenant context is
 * already embedded in each line description).
 *
 * The download link points at /api/billing/invoices/[n]/pdf
 * which serves the stored PDF blob inline. Customers using a
 * link from their email will hit the same route via this page.
 */
export function CustomerInvoiceDetail({ invoice, lines }: Props) {
  const t = useTranslations("customerBilling");
  const fmt = useFormatter();

  return (
    <div className="space-y-6 animate-in">
      <PaymentStatusBanner />
      <div className="flex items-start justify-between gap-4 flex-wrap">
        <div>
          <div className="flex items-center gap-3 mb-2">
            <h1 className="font-display text-2xl font-semibold">
              {invoice.invoiceNumber}
            </h1>
            <span
              className={`text-[10px] uppercase tracking-wider px-2 py-1 rounded-md font-semibold ${
                statusColors[invoice.status] ?? "text-text-muted bg-surface-3"
              }`}
            >
              {t(`status.${invoice.status}` as any)}
            </span>
          </div>
          <p className="text-sm text-text-secondary">
            {fmt.dateTime(new Date(invoice.periodStart), { dateStyle: "long" })}
            <span className="text-text-muted mx-1">→</span>
            {fmt.dateTime(new Date(invoice.periodEnd), { dateStyle: "long" })}
          </p>
        </div>
        <div className="flex items-start gap-2 flex-wrap">
          {/* Phase 4: Pay-with-card available for open + overdue.
              Paid/void/draft/uncollectible hide the button — the
              API also enforces this, so client-side hiding is just
              for the visible affordance. */}
          {(invoice.status === "open" || invoice.status === "overdue") && (
            <PayInvoiceButton invoiceNumber={invoice.invoiceNumber} />
          )}
          <a
            href={`/api/billing/invoices/${encodeURIComponent(invoice.invoiceNumber)}/pdf`}
            target="_blank"
            rel="noopener noreferrer"
            className="px-4 py-2 rounded-md bg-surface-3 hover:bg-surface-2 border border-border text-sm font-medium transition-colors"
          >
            {t("downloadPdf")}
          </a>
        </div>
      </div>

      <Card>
        <div className="space-y-2 mb-4">
          <div className="flex justify-between text-sm">
            <span className="text-text-muted">{t("billedToLabel")}</span>
            <span>{invoice.billingSnapshot.companyName}</span>
          </div>
          <div className="flex justify-between text-sm">
            <span className="text-text-muted">{t("issuedAtLabel")}</span>
            <span>
              {fmt.dateTime(new Date(invoice.issuedAt), { dateStyle: "medium" })}
            </span>
          </div>
          <div className="flex justify-between text-sm">
            <span className="text-text-muted">{t("dueAtLabel")}</span>
            <span>
              {fmt.dateTime(new Date(invoice.dueAt), { dateStyle: "medium" })}
            </span>
          </div>
          {invoice.status === "paid" && invoice.paidAt && (
            <div className="flex justify-between text-sm">
              <span className="text-text-muted">{t("paidAtLabel")}</span>
              <span>
                {fmt.dateTime(new Date(invoice.paidAt), { dateStyle: "medium" })}
              </span>
            </div>
          )}
        </div>
      </Card>

      <Card>
        <table className="w-full text-sm">
          <thead className="text-xs text-text-muted text-left">
            <tr>
              <th className="pb-2">{t("descriptionCol")}</th>
              <th className="pb-2 text-right">{t("qtyCol")}</th>
              <th className="pb-2 text-right">{t("unitCol")}</th>
              <th className="pb-2 text-right">{t("amountCol")}</th>
            </tr>
          </thead>
          <tbody>
            {lines.map((ln) => (
              <tr key={ln.id} className="border-t border-border align-top">
                <td className="py-2">{ln.description}</td>
                <td className="py-2 text-right font-mono text-xs">
                  {ln.quantity}
                  {ln.unitLabel ? ` ${ln.unitLabel}` : ""}
                </td>
                <td className="py-2 text-right font-mono text-xs">
                  {ln.unitPriceChf.toFixed(2)}
                </td>
                <td className="py-2 text-right font-mono">
                  {ln.amountChf.toFixed(2)}
                </td>
              </tr>
            ))}
          </tbody>
          <tfoot>
            <tr className="border-t border-border">
              <td colSpan={3} className="pt-3 text-right text-text-muted">
                {t("subtotalLabel")}
              </td>
              <td className="pt-3 text-right font-mono">
                {invoice.subtotalChf.toFixed(2)}
              </td>
            </tr>
            <tr>
              <td colSpan={3} className="pt-1 text-right text-text-muted">
                {t("vatLabel", { rate: invoice.vatRate.toFixed(2) })}
              </td>
              <td className="pt-1 text-right font-mono">
                {invoice.vatAmountChf.toFixed(2)}
              </td>
            </tr>
            <tr>
              <td colSpan={3} className="pt-2 text-right font-semibold">
                {t("totalLabel")}
              </td>
              <td className="pt-2 text-right font-mono font-semibold text-base">
                CHF {invoice.totalChf.toFixed(2)}
              </td>
            </tr>
          </tfoot>
        </table>
      </Card>
    </div>
  );
}