import { NextRequest, NextResponse } from "next/server";

// Same-origin proxy for the URL-shortener create endpoint. Client components
// (text-selection toolbar, share modal) call /api/share so the actual BFF
// request happens server-side — this is the only way to read `BFF_URL`,
// since Next.js does not expose non-`NEXT_PUBLIC_` env vars to the browser
// bundle. Same pattern as /api/search.
const BFF_BASE = process.env.BFF_URL || "http://localhost:8080";

export async function POST(request: NextRequest) {
  let body: unknown;
  try {
    body = await request.json();
  } catch {
    return NextResponse.json(
      { success: false, error: { code: 400, message: "invalid JSON body" } },
      { status: 400 },
    );
  }

  const url =
    body && typeof body === "object" && "url" in body
      ? (body as { url: unknown }).url
      : null;
  if (typeof url !== "string" || !url.startsWith("/")) {
    return NextResponse.json(
      {
        success: false,
        error: { code: 400, message: "url must be a same-site path" },
      },
      { status: 400 },
    );
  }

  try {
    const res = await fetch(new URL("/api/v1/share", BFF_BASE).toString(), {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
        Accept: "application/json",
      },
      body: JSON.stringify({ url }),
      cache: "no-store",
    });

    const text = await res.text();
    return new NextResponse(text, {
      status: res.status,
      headers: { "Content-Type": "application/json" },
    });
  } catch {
    return NextResponse.json(
      { success: false, error: { code: 502, message: "BFF unreachable" } },
      { status: 502 },
    );
  }
}