package com.baiyue.eventbridge.trace;

import com.baiyue.common.web.CorrelationContext;
import com.baiyue.eventbridge.domain.BridgeInbox;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.Test;
import org.slf4j.MDC;

import java.net.URI;
import java.net.http.HttpRequest;

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

class EventBridgeTracePropagationTest {

    @AfterEach
    void clearMdc() {
        MDC.clear();
    }

    @Test
    void envelopeUuidFlowsThroughMdcAndRawHttpAsAChildSpan() {
        BridgeInbox event = new BridgeInbox();
        event.setTraceId("550e8400-e29b-41d4-a716-446655440000");
        event.setCorrelationId("ORDER:customer-99:booking-123");
        event.setEventId("event-business-id");

        try (EventBridgeTraceScope ignored = EventBridgeTraceScope.open(event)) {
            String localSpan = MDC.get(CorrelationContext.SPAN_ID);
            HttpRequest.Builder builder = HttpRequest.newBuilder(URI.create("http://127.0.0.1/internal"))
                    .header(CorrelationContext.REQUEST_ID_HEADER, event.getEventId())
                    .header(CorrelationContext.TRACE_ID_HEADER, event.getCorrelationId())
                    .header(CorrelationContext.TRACE_PARENT_HEADER,
                            "00-aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa-bbbbbbbbbbbbbbbb-00");
            HttpRequest request = new EventBridgeHttpTracePropagation().apply(builder).GET().build();

            assertThat(MDC.get(CorrelationContext.TRACE_ID))
                    .isEqualTo("550e8400e29b41d4a716446655440000");
            assertThat(request.headers().firstValue(CorrelationContext.TRACE_ID_HEADER))
                    .contains("550e8400e29b41d4a716446655440000");
            assertThat(request.headers().firstValue(CorrelationContext.REQUEST_ID_HEADER).orElseThrow())
                    .matches("[0-9a-f-]{36}").isNotEqualTo(event.getEventId());
            assertThat(request.headers().firstValue(CorrelationContext.TRACE_PARENT_HEADER).orElseThrow())
                    .matches("00-550e8400e29b41d4a716446655440000-[0-9a-f]{16}-01")
                    .doesNotContain(localSpan);
        }

        assertThat(MDC.get(CorrelationContext.TRACE_ID)).isNull();
    }

    @Test
    void invalidLegacyEnvelopeTraceIsSafelyRebuiltAndPreviousMdcIsRestored() {
        MDC.put("existing", "preserved");
        BridgeInbox event = new BridgeInbox();
        event.setTraceId("JWT-or-business-id-value");

        try (EventBridgeTraceScope ignored = EventBridgeTraceScope.open(event)) {
            assertThat(MDC.get(CorrelationContext.TRACE_ID)).matches("[0-9a-f]{32}")
                    .isNotEqualTo(event.getTraceId());
        }

        assertThat(MDC.get("existing")).isEqualTo("preserved");
        assertThat(MDC.get(CorrelationContext.TRACE_ID)).isNull();
    }
}