/**
 * Test setup for @suaveplan/api-tenant-resolver-subdomain.
 *
 * Installs a real in-memory OpenTelemetry MeterProvider BEFORE any source
 * module imports, so the meter resolved on first call binds to it and
 * test assertions can observe every counter / histogram emission.
 */
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);

export async function flushTestMetrics() {
    await testMeterProvider.forceFlush();
    const collected = testInMemoryMetricExporter.getMetrics();
    testInMemoryMetricExporter.reset();
    return collected;
}