'use strict';

const opentelemetry = require('@opentelemetry/core');
const { NodeTracerRegistry } = require('@opentelemetry/node');
const { SimpleSpanProcessor } = require('@opentelemetry/tracing');
const { JaegerExporter } = require('@opentelemetry/exporter-jaeger');
const { ZipkinExporter } = require('@opentelemetry/exporter-zipkin');
const EXPORTER = process.env.EXPORTER || '';

function setupTracerAndExporters(service) {
  const registry = new NodeTracerRegistry({
      plugins: {
          dns: {
            enabled: true,
            path: '@opentelemetry/plugin-dns',
            // Avoid dns lookup loop with http zipkin calls
            ignoreHostnames: ['localhost']
        }
      }
  });

  let exporter;
  if (EXPORTER.toLowerCase().startsWith('z')) {
    exporter = new ZipkinExporter({
      serviceName: service,
    });
  } else {
    exporter = new JaegerExporter({
      serviceName: service,
    });
  }

  registry.addSpanProcessor(new SimpleSpanProcessor(exporter));

  // Initialize the OpenTelemetry APIs to use the BasicTracerRegistry bindings
  opentelemetry.initGlobalTracerRegistry(registry);
}

exports.setupTracerAndExporters = setupTracerAndExporters;