(() => {
  "use strict";
  if (window.HockeyPerformance) return;
  const metrics = { script_started_ms: performance.now() };
  let errors = 0;
  let readySent = false;

  function post(event, message = "", values = {}) {
    const payload = {
      event,
      build: String(window.UI_BUILDER_BOOT?.buildVersion || ""),
      message: String(message).slice(0, 2000),
      path: location.pathname,
      metrics: values,
    };
    // A diagnostic must not slow first paint or produce a diagnostic loop.
    fetch("/api/hockey/client-events", {
      method: "POST", credentials: "same-origin", cache: "no-store", keepalive: true,
      headers: { "Content-Type": "application/json" }, body: JSON.stringify(payload),
    }).catch(() => {});
  }

  window.HockeyPerformance = {
    mark(name, value) { if (Number.isFinite(value)) metrics[name] = value; },
    async measure(name, work) {
      const start = performance.now();
      try { return await work(); }
      finally { metrics[name] = performance.now() - start; }
    },
    getMetrics() { return { ...metrics }; },
    reportError(message) { if (errors++ < 10) post("error", message); },
  };

  window.addEventListener("hockey:runtime-ready", () => {
    if (readySent) return;
    readySent = true;
    metrics.runtime_ready_ms = performance.now();
    const navigation = performance.getEntriesByType("navigation")[0];
    if (navigation) {
      metrics.server_response_ms = Math.max(0, navigation.responseStart - navigation.requestStart);
      metrics.document_download_ms = Math.max(0, navigation.responseEnd - navigation.responseStart);
      metrics.connection_ms = Math.max(0, navigation.connectEnd - navigation.connectStart);
      metrics.dom_interactive_ms = Math.max(0, navigation.domInteractive);
    }
    const resources = performance.getEntriesByType("resource");
    metrics.resource_count = resources.length;
    metrics.transfer_bytes = resources.reduce((sum, item) => sum + (item.transferSize || 0), 0);
    metrics.decoded_bytes = resources.reduce((sum, item) => sum + (item.decodedBodySize || 0), 0);
    metrics.cached_resources = resources.filter(item => item.transferSize === 0 && item.decodedBodySize > 0).length;
    const send = () => {
      metrics.first_ready_paint_ms = performance.now();
      post("ready", "Интерфейс готов к работе", { ...metrics });
    };
    // Two frames include a paint, with a fallback for an inactive browser tab.
    let sent = false;
    const once = () => { if (!sent) { sent = true; send(); } };
    requestAnimationFrame(() => requestAnimationFrame(once));
    setTimeout(once, 1000);
  });

  window.addEventListener("error", event => {
    if (errors++ >= 10) return;
    const file = String(event.filename || "").split("?")[0];
    post("error", `${event.message || "Ошибка браузера"} · ${file}:${event.lineno || 0}:${event.colno || 0}`);
  });
  window.addEventListener("unhandledrejection", event => {
    if (errors++ >= 10) return;
    post("unhandledrejection", String(event.reason?.message || event.reason || "Необработанная ошибка"));
  });
})();