// ============================================================
// Product analytics + error capture (Phase 2)
//
// - OpenPanel (@openpanel/web): funnels/usage — initialized only when
//   VITE_OPENPANEL_URL and VITE_OPENPANEL_CLIENT_ID are set (build args),
//   so local dev and air-gapped environments stay silent.
// - GlitchTip (@sentry/react): frontend exception capture, only when
//   VITE_SENTRY_DSN is set.
//
// Both are no-ops without configuration; every helper is safe to call
// unconditionally from anywhere in the app.
// ============================================================
import * as Sentry from "@sentry/react";

type Props = Record<string, unknown>;

declare global {
  interface Window {
    op?: (...args: unknown[]) => void;
  }
}

const OPENPANEL_URL = (import.meta.env?.VITE_OPENPANEL_URL as string | undefined)?.trim();
const OPENPANEL_CLIENT_ID = (import.meta.env?.VITE_OPENPANEL_CLIENT_ID as string | undefined)?.trim();
const OPENPANEL_SCRIPT_URL = (import.meta.env?.VITE_OPENPANEL_SCRIPT_URL as string | undefined)?.trim();
const SENTRY_DSN = (import.meta.env?.VITE_SENTRY_DSN as string | undefined)?.trim();

/**
 * Load the OpenPanel browser script (op1.js) and its queueing shim.
 *
 * The shim is OpenPanel's documented snippet: `window.op` becomes a queue while the
 * script is in flight, so `op("init", …)` can be called immediately and the real
 * script drains the queue on load. Without it, every `window.op?.()` call here is a
 * silent no-op — which is what happened before this loader existed.
 */
function loadOpenPanelScript(src: string): void {
  if (document.querySelector("script[data-openpanel]")) return;
  const shim = document.createElement("script");
  shim.textContent =
    'window.op=window.op||function(){var n=[];return new Proxy(function(){arguments.length&&n.push([].slice.call(arguments))},{get:function(t,r){return"q"===r?n:function(){n.push([r].concat([].slice.call(arguments)))}},has:function(t,r){return"q"===r}}) }();';
  document.head.appendChild(shim);
  const script = document.createElement("script");
  script.src = src;
  script.async = true;
  script.defer = true;
  script.dataset.openpanel = "1";
  document.head.appendChild(script);
}

export function initAnalytics(): void {
  if (SENTRY_DSN) {
    Sentry.init({
      dsn: SENTRY_DSN,
      environment: (import.meta.env?.MODE as string | undefined) ?? "production",
      // Frontend traces are expensive and rarely needed — errors only.
      tracesSampleRate: 0,
    });
  }
  if (OPENPANEL_URL && OPENPANEL_CLIENT_ID) {
    try {
      if (OPENPANEL_SCRIPT_URL) loadOpenPanelScript(OPENPANEL_SCRIPT_URL);
      window.op?.("init", {
        apiUrl: OPENPANEL_URL,
        clientId: OPENPANEL_CLIENT_ID,
        trackScreenViews: true, // pageview → which pages users visit
      });
    } catch {
      /* analytics must never break the app */
    }
  }
}

/** Attach the ERP user identity to analytics (after login / app load). */
export function identifyUser(profile: {
  id?: string;
  name?: string;
  role?: string | null;
}): void {
  if (!profile.id) return;
  try {
    window.op?.("identify", {
      profileId: profile.id,
      firstName: profile.name || undefined,
      data: { role: profile.role ?? undefined },
    });
    track("user_identified", { role: profile.role ?? undefined });
  } catch {
    /* ignore */
  }
}

export function track(event: string, properties?: Props): void {
  try {
    window.op?.("track", event, properties ?? {});
  } catch {
    /* ignore */
  }
}

export function captureError(err: unknown): void {
  if (SENTRY_DSN) Sentry.captureException(err);
}

export const analyticsEnabled = Boolean(OPENPANEL_URL && OPENPANEL_CLIENT_ID);