Function handler

api/feedback.ts:117–182

(req: VercelRequest, res: VercelResponse)

// ---------- Handler ----------

export default async function handler(req: VercelRequest, res: VercelResponse) {
  if (req.method !== "POST") {
    return res.status(405).json({ error: "Method not allowed" });
  }

  // Rate limiting is handled by Vercel Firewall (project dashboard)

  // Validate
  const {
    page_url: pageUrl,
    rating,
    reason,
    timestamp,
  } = req.body as FeedbackBody;

  if (!pageUrl || !rating || !["yes", "no"].includes(rating)) {
    return res
      .status(400)
      .json({ error: "page_url and rating (yes/no) are required" });
  }

  if (!isValidPageUrl(pageUrl)) {
    return res.status(400).json({ error: "invalid page_url" });
  }

  const cleanReason = reason ? sanitizeFeedbackText(reason) : "";

  if (rating === "no" && !cleanReason) {
    return res
      .status(400)
      .json({ error: "reason is required for negative feedback" });
  }
  const ts = timestamp ?? new Date().toISOString();

  // Google Sheet — every submission
  try {
    await appendToSheet([
      ts,
      pageUrl,
      rating,
      cleanReason,
      getDeviceType((req.headers["user-agent"] as string) ?? ""),
    ]);
  } catch (err) {
    console.error("Google Sheets append failed:", err);
    // Don't block the response
  }

  // Negative + reason → GitHub issue, then Slack with issue link
  if (rating === "no" && cleanReason) {
    let issueUrl: string | null = null;
    try {
      issueUrl = await createGitHubIssue(pageUrl, cleanReason);
    } catch (err) {
      console.error("GitHub issue failed:", err);
    }

    try {