package com.ankurm.otel;

import java.util.ArrayList;
import java.util.List;
import java.util.TreeSet;

import org.junit.jupiter.api.Test;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.web.client.RestClient;

import static org.assertj.core.api.Assertions.assertThat;

/**
 * What a dashboard query sees. Scrapes /actuator/prometheus after one request and lists the
 * http_server* families and one labelled sample, for the default conventions and for the
 * open-telemetry conventions (spelled the way RC1 accepts it).
 */
class PrometheusNamesTest {

	@Test
	void promNames() throws Exception {
		Transcript t = new Transcript("06-prometheus-names");
		List<String> modes = List.of("micrometer", "opentelemetry");
		java.util.Map<String, List<String>> families = new java.util.LinkedHashMap<>();
		for (String mode : modes) {
			ConfigurableApplicationContext ctx = Apps.start("management.observations.conventions=" + mode,
					"management.otlp.metrics.export.enabled=false");
			Apps.call(ctx, "/hello/ankur");
			io.micrometer.core.instrument.MeterRegistry registry = ctx.getBean(io.micrometer.core.instrument.MeterRegistry.class);
			Apps.awaitHttpMeter(registry);
			String port = ctx.getEnvironment().getProperty("local.server.port");
			String body = RestClient.create().get().uri("http://localhost:" + port + "/actuator/prometheus")
				.retrieve().body(String.class);
			TreeSet<String> names = new TreeSet<>();
			String sample = "";
			for (String line : body.split("\n")) {
				if (line.startsWith("http_server")) {
					names.add(line.substring(0, line.indexOf('{') > 0 ? line.indexOf('{') : line.indexOf(' ')));
					if (line.contains("_count{") && sample.isEmpty()) {
						sample = line.substring(0, line.lastIndexOf(' '));
					}
				}
			}
			t.line("");
			t.line("== management.observations.conventions=" + mode);
			names.forEach(n -> t.line("   " + n));
			t.line("   sample: " + sample);
			families.put(mode, new ArrayList<>(names));
			ctx.close();
		}
		t.write();
		if (Transcript.is42()) {
			assertThat(families.get("micrometer")).contains("http_server_requests_seconds_count");
			assertThat(families.get("opentelemetry")).contains("http_server_request_duration_seconds_count");
		}
	}
}