package com.ankurm.otel;

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

import io.micrometer.core.instrument.Meter;
import io.micrometer.core.instrument.MeterRegistry;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.springframework.boot.test.system.CapturedOutput;
import org.springframework.boot.test.system.OutputCaptureExtension;
import org.springframework.context.ConfigurableApplicationContext;

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

/**
 * Two smaller 4.2 changes that break dashboards and log queries rather than builds: the MDC keys
 * that carry the trace and span ids, and the active-observation LongTaskTimer that is no longer
 * created by default.
 */
@ExtendWith(OutputCaptureExtension.class)
class MdcAndLongTaskTimerTest {

	@Test
	void mdcKeys(CapturedOutput output) {
		Transcript t = new Transcript("04-mdc-keys");
		// The pattern reads both the default key names and the custom ones, so one log line shows
		// which key the tracing bridge really populated.
		ConfigurableApplicationContext ctx = Apps.start("management.otlp.metrics.export.enabled=false",
				"management.tracing.mdc.trace-id-key=trace_id", "management.tracing.mdc.span-id-key=span_id",
				"logging.pattern.correlation=default[%X{traceId:-}] custom[%X{trace_id:-}] ");
		Apps.call(ctx, "/hello/ankur");
		ctx.close();
		String line = output.getAll().lines().filter(l -> l.contains("handling hello for ankur")).findFirst().orElseThrow();
		String correlation = line.substring(line.indexOf("default["), line.indexOf("] : ") > 0 ? line.indexOf("] :") : line.length());
		t.line("management.tracing.mdc.trace-id-key = trace_id");
		t.line("management.tracing.mdc.span-id-key  = span_id");
		t.line("log pattern correlation part reads both MDC keys");
		t.line("");
		t.line("log line: " + line.replaceAll("^\\S+\\s+", "").replaceAll("(?<=\\[)[0-9a-f]{32}(?=\\])", "<32-hex-trace-id>"));
		boolean defaultKeyFilled = line.matches(".*default\\[[0-9a-f]{32}\\].*");
		boolean customKeyFilled = line.matches(".*custom\\[[0-9a-f]{32}\\].*");
		t.line("default key traceId populated: " + defaultKeyFilled);
		t.line("custom key trace_id populated: " + customKeyFilled);
		if (Transcript.is42()) {
			assertThat(customKeyFilled).isTrue();
			assertThat(defaultKeyFilled).isFalse();
		}
		else {
			assertThat(customKeyFilled).isFalse();
			assertThat(defaultKeyFilled).isTrue();
		}
		t.write();
	}

	@Test
	void activeLongTaskTimer() throws Exception {
		Transcript t = new Transcript("05-active-long-task-timer");
		for (String setting : List.of("(default)", "management.metrics.observations.include-active-long-task-timer=true")) {
			ConfigurableApplicationContext ctx = setting.startsWith("(")
					? Apps.start("management.otlp.metrics.export.enabled=false")
					: Apps.start("management.otlp.metrics.export.enabled=false", setting);
			Apps.call(ctx, "/hello/ankur");
			MeterRegistry registry = ctx.getBean(MeterRegistry.class);
			Apps.awaitHttpMeter(registry);
			TreeSet<String> names = new TreeSet<>();
			for (Meter m : registry.getMeters()) {
				if (m.getId().getName().startsWith("http.server")) {
					names.add(m.getId().getName() + "  (" + m.getId().getType() + ")");
				}
			}
			t.line("");
			t.line("== " + setting);
			names.forEach(n -> t.line("   " + n));
			boolean active = names.stream().anyMatch(n -> n.startsWith("http.server.requests.active"));
			t.line("   http.server.requests.active present: " + active);
			if (Transcript.is42()) {
				assertThat(active).isEqualTo(!setting.startsWith("("));
			}
			else if (setting.startsWith("(")) {
				assertThat(active).isTrue();
			}
			ctx.close();
		}
		t.write();
	}
}