import { NextRequest, NextResponse } from "next/server";
import { listOwnedOrders } from "@/lib/orders-store";
import { requireOrderOwner } from "@/src/auth/require-order-owner";
import { isSiaxError, siaxErrorResponseForLegacy } from "../../siax-error-mapping";

/**
 * GET /api/orders/export (våg 3.4, DoD §56) — CSV-export of the authenticated
 * owner's orders. Same fail-closed auth as GET/POST /api/orders (this path is
 * outside middleware.ts's /api/0pt matcher, so the Zitadel verifier runs here).
 *
 * RFC 4180: CRLF line endings, fields containing comma, quote or newline are
 * quoted with doubled quotes, header row always present.
 *
 * Locale note: deposit_ore / total_ore are exported as RAW ÖRE — öre is the
 * canonical unit in the order contract; formatting (SEK, thousand separators)
 * happens in the UI layer, never in the export.
 *
 * Cap note (DoD §56): NO row truncation/limiting — an export must be complete.
 */

function csvEscape(value: string): string {
  if (/[",\r\n]/.test(value)) return `"${value.replace(/"/g, '""')}"`;
  return value;
}

export async function GET(req: NextRequest) {
  const auth = await requireOrderOwner(req);
  if (auth.response) return auth.response;
  try {
    const orders = await listOwnedOrders(auth.owner.tenantId);
    const header = ["order_id", "flow", "status", "deposit_ore", "total_ore"];
    const rows = orders.map((o) =>
      [o.order_id, o.flow, o.status, String(o.deposit_ore), String(o.total_ore)].map(csvEscape).join(","),
    );
    const csv = [header.join(","), ...rows].join("\r\n") + "\r\n";
    const date = new Date().toISOString().slice(0, 10);
    return new NextResponse(csv, {
      status: 200,
      headers: {
        "Content-Type": "text/csv; charset=utf-8",
        "Content-Disposition": `attachment; filename="orders-${date}.csv"`,
      },
    });
  } catch (err: unknown) {
    if (isSiaxError(err)) return siaxErrorResponseForLegacy(err);
    throw err;
  }
}