{# Shared chart-readiness coordinator for the Playwright PDF
   renderer. Owns window.fsReportReady. Exposes fsBeaconAcquire()
   to register a pending chart and fsBeaconRelease() to mark it
   done; fsReportReady flips to true when the pending counter
   reaches zero.

   Used by both _chart_ready.html (Chart.js wrapper) and
   _echarts_ready.html (ECharts wrapper) so PDFs that include
   both libraries are captured only after BOTH finish painting.

   COMPATIBILITY: also exposes window.fsReportPendingCharts as a
   live numeric view of the internal counter. pdf_renderer.py uses
   this for BEACON_TIMEOUT diagnostics — preserving the name lets
   us replace the coordinator without changing the diagnostic.

   EMPTY-DATA / NO-CHART SAFETY NET: if no chart has acquired the
   beacon by paint time (e.g., the recipe declared charts in YAML
   but the data was empty, or the chart library CDN was blocked),
   we flip fsReportReady=true after DOMContentLoaded + setTimeout(0)
   so the PDF renderer doesn't hang waiting for a beacon that will
   never fire. Mirrors the empty-data safety net the prior
   _chart_ready.html shipped (which is being delegated to here).

   IDEMPOTENT: including this partial twice in the same document
   (e.g., a template that includes both chart-ready partials) is
   safe — the bootstrap script guards with a typeof check, so
   only the first include initializes the coordinator. Subsequent
   includes are no-ops and do NOT reset the flag or counter. #}
<script>
(function () {
    if (typeof window.fsBeaconAcquire !== 'function') {
        window.fsReportReady = false;
        var pending = 0;
        // Live view of the counter for pdf_renderer.py BEACON_TIMEOUT
        // diagnostics. Defined via property accessor so it always
        // reflects the current value.
        Object.defineProperty(window, 'fsReportPendingCharts', {
            get: function () { return pending; },
            configurable: true,
        });
        window.fsBeaconAcquire = function () {
            // Late-acquire safety: if the empty-data safety net already
            // flipped fsReportReady=true and a delayed script then calls
            // acquire (async chart init, deferred render), reset to false
            // so Playwright doesn't capture before the new chart paints.
            // Release will flip it back true when the counter returns
            // to zero.
            if (window.fsReportReady === true) {
                window.fsReportReady = false;
            }
            pending++;
        };
        window.fsBeaconRelease = function () {
            pending--;
            if (pending < 0) {
                // Over-release: more releases than acquires. Indicates a wrapper
                // bug or manual misuse. We clamp pending to 0 so fsReportReady
                // doesn't flip multiple times, but log the issue loudly so
                // developers see it in dev tools / Playwright console capture.
                console.error(
                    'fsBeaconRelease called more times than fsBeaconAcquire. ' +
                    'Pending went negative — clamping to 0. This indicates a chart-' +
                    'wrapper bug or double-release; investigate.'
                );
                pending = 0;
            }
            if (pending <= 0) {
                pending = 0;
                window.fsReportReady = true;
            }
        };
        // Empty-data safety net: if nobody acquired by paint time, flip
        // ready so the PDF renderer doesn't hang. (Late acquires reset
        // the flag via fsBeaconAcquire above.)
        window.addEventListener('DOMContentLoaded', function () {
            setTimeout(function () {
                if (pending === 0 && !window.fsReportReady) {
                    window.fsReportReady = true;
                }
            }, 0);
        });
    }
})();
</script>