// tracing.ts — Import ANTES que cualquier otro módulo
import { NodeSDK } from "@opentelemetry/sdk-node";
import { OTLPTraceExporter } from "@opentelemetry/exporter-trace-otlp-http";
import { OTLPMetricExporter } from "@opentelemetry/exporter-metrics-otlp-http";
import { getNodeAutoInstrumentations } from "@opentelemetry/auto-instrumentations-node";
import { Resource } from "@opentelemetry/resources";

// NutriFlow — SigNoz self-hosted @ signoz.nutriflow.internal:4318
const SIGNOZ_ENDPOINT = process.env.OTEL_ENDPOINT
  ?? "http://signoz.nutriflow.internal:4318";

const sdk = new NodeSDK({
  resource: new Resource({
    "service.name": process.env.SERVICE_NAME,    // api-gateway | nutrition-service
    "service.version": process.env.IMAGE_TAG,
    "deployment.environment": "production",
    "cloud.provider": "aws",
    "cloud.region": "eu-west-1",
  }),
  traceExporter: new OTLPTraceExporter({
    url: `${SIGNOZ_ENDPOINT}/v1/traces`,
  }),
  instrumentations: [
    getNodeAutoInstrumentations({
      // Auto-detecta: Express, pg, Redis, HTTP, SQS, gRPC
      "@opentelemetry/instrumentation-fs": { enabled: false },
    }),
  ],
});

sdk.start();
process.on("SIGTERM", () => sdk.shutdown());

import { metrics } from "@opentelemetry/api";

const meter = metrics.getMeter("nutriflow-business");

// Planes contratados (counter — solo sube)
export const subsProcessed = meter.createCounter(
  "subs.processed", { unit: "subscriptions" }
);

// Usuarios activos (up/down counter)
export const activeUsers = meter.createUpDownCounter(
  "users.active"
);

// Revenue por pedido (histograma para percentiles)
export const revenueEur = meter.createHistogram(
  "revenue.eur", { unit: "EUR" }
);

// Recetas consultadas
export const recipeViews = meter.createCounter(
  "recipe.views"
);

// Uso en el flujo de negocio:
function onSubscriptionCreated(sub: Subscription) {
  subsProcessed.add(1, {
    "plan.tier": sub.tier,          // "pro" | "team" | "enterprise"
    "plan.billing": sub.billing,   // "monthly" | "annual"
    "company.size": sub.companySize,
  });
  revenueEur.record(sub.amountEur, {
    "plan.tier": sub.tier,
  });
}