"use client";

import Script from "next/script";
import { ANALYTICS_PROXY_PATH, redactPayload, type UmamiPayload } from "@/lib/analytics";

/** Name of the global the tracker's `data-before-send` hook resolves. */
const BEFORE_SEND = "__umamiBeforeSend";

declare global {
  interface Window {
    [BEFORE_SEND]?: (type: string, payload: UmamiPayload) => UmamiPayload;
  }
}

// Registered at module scope rather than in an effect: the tracker reads
// `window[BEFORE_SEND]` at send time, and this client chunk is evaluated before
// next/script injects the tag, so there is no window in which an unredacted
// event could slip out.
if (typeof window !== "undefined") {
  window[BEFORE_SEND] = (_type, payload) => redactPayload(payload);
}

/**
 * Self-hosted Umami analytics.
 *
 * The tracker and its beacon are both served from this origin via the
 * `/_a` rewrite in next.config.mjs. That matters for more than ad-blockers: the
 * CSP in middleware.ts uses `'strict-dynamic'`, which makes browsers ignore host
 * allowlists in `script-src` entirely — so allowlisting the Umami domain there
 * would not have worked, and `connect-src 'self'` would still have blocked the
 * beacon. Proxying keeps both same-origin and the policy unrelaxed.
 */
export function UmamiAnalytics({ websiteId }: { websiteId: string }) {
  return (
    <Script
      src={`${ANALYTICS_PROXY_PATH}/script.js`}
      strategy="afterInteractive"
      data-website-id={websiteId}
      // Point the beacon at the proxied path instead of letting the tracker
      // derive it from its own src.
      data-host-url={ANALYTICS_PROXY_PATH}
      // Drop query strings and fragments at the source. /reset-password carries a
      // live reset token in `?token=` and /sign-in carries `?redirect=`.
      data-exclude-search="true"
      data-exclude-hash="true"
      data-before-send={BEFORE_SEND}
      // Honour the browser's Do Not Track signal.
      data-do-not-track="true"
    />
  );
}