'use strict';

const { NodeSDK } = require('@opentelemetry/sdk-node');
const { getNodeAutoInstrumentations } = require('@opentelemetry/auto-instrumentations-node');
const { OTLPTraceExporter } = require('@opentelemetry/exporter-trace-otlp-grpc');
const { OTLPMetricExporter } = require('@opentelemetry/exporter-metrics-otlp-grpc');
const { PeriodicExportingMetricReader } = require('@opentelemetry/sdk-metrics');

const otlpEndpoint = process.env.OTEL_EXPORTER_OTLP_ENDPOINT || 'http://otel-collector-opentelemetry-collector.monitoring:4317';
const serviceName = process.env.OTEL_SERVICE_NAME || 'demo-app';

const traceExporter = new OTLPTraceExporter({
  url: otlpEndpoint,
});

const metricExporter = new OTLPMetricExporter({
  url: otlpEndpoint,
});

const metricReader = new PeriodicExportingMetricReader({
  exporter: metricExporter,
  exportIntervalMillis: 15000,
});

const sdk = new NodeSDK({
  serviceName,
  traceExporter,
  metricReader,
  instrumentations: [
    getNodeAutoInstrumentations({
      '@opentelemetry/instrumentation-fs': { enabled: false },
    }),
  ],
});

sdk.start();

process.on('SIGTERM', () => {
  sdk.shutdown()
    .then(() => console.log('OpenTelemetry SDK shut down'))
    .catch((err) => console.error('Error shutting down OpenTelemetry SDK', err))
    .finally(() => process.exit(0));
});

console.log(`OpenTelemetry initialized for service "${serviceName}" -> ${otlpEndpoint}`);