/**
 * Test-environment setup for @suaveplan/server-keys.
 *
 * Wires a real in-memory OpenTelemetry `MeterProvider` BEFORE any source
 * module is imported, so the meter resolved by `instruments.ts` at module
 * load is the real provider's meter — not the noop fallback. Tests that
 * inspect emitted metrics flush via `flushTestMetrics`.
 *
 * Node ≥18 already exposes `crypto.subtle` and `crypto.getRandomValues`
 * globally, so no crypto polyfill is required.
 */
import { metrics } from "@opentelemetry/api";
import {
    AggregationTemporality,
    InMemoryMetricExporter,
    MeterProvider,
    PeriodicExportingMetricReader,
} from "@opentelemetry/sdk-metrics";

export const testInMemoryMetricExporter = new InMemoryMetricExporter(
    AggregationTemporality.CUMULATIVE
);

const reader = new PeriodicExportingMetricReader({
    exporter: testInMemoryMetricExporter,
    exportIntervalMillis: 60_000,
});

export const testMeterProvider = new MeterProvider({ readers: [reader] });
metrics.setGlobalMeterProvider(testMeterProvider);

/** Force-flush the test meter provider and return the captured snapshots. */
export async function flushTestMetrics() {
    await testMeterProvider.forceFlush();
    const collected = testInMemoryMetricExporter.getMetrics();
    testInMemoryMetricExporter.reset();
    return collected;
}