import { NextResponse } from "next/server";
import { getSessionUser } from "@/lib/session";
import { getInvoiceByNumberForOrg, getInvoicePdf } from "@/lib/db";

/**
 * GET /api/billing/invoices/[invoiceNumber]/pdf
 *
 * Customer-facing PDF download. Same Uint8Array.from() variance
 * fix as the admin route — see /api/admin/billing/invoices/[id]/pdf
 * for the rationale.
 *
 * Authorization: looks up the invoice by number with org scope
 * baked into the query, then re-fetches the PDF blob by id. A
 * customer can't probe another org's invoice numbers — they get
 * 404 either way.
 */
export async function GET(
  _request: Request,
  { params }: { params: Promise<{ invoiceNumber: string }> }
) {
  const user = await getSessionUser();
  if (!user) {
    return new NextResponse("Unauthorized", { status: 401 });
  }
  const { invoiceNumber } = await params;
  const detail = await getInvoiceByNumberForOrg(invoiceNumber, user.orgId);
  if (!detail) {
    return new NextResponse("Not found", { status: 404 });
  }
  const pdf = await getInvoicePdf(detail.invoice.id);
  if (!pdf) {
    return new NextResponse("PDF not available", { status: 404 });
  }
  const body = Uint8Array.from(pdf.data);
  return new NextResponse(body, {
    status: 200,
    headers: {
      "Content-Type": "application/pdf",
      "Content-Disposition": `inline; filename="${pdf.filename}"`,
      "Cache-Control": "private, max-age=0, must-revalidate",
    },
  });
}