package com.baiyue.common.web;

import org.junit.jupiter.api.Test;

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

class TraceParentTest {

    @Test
    void parsesCanonicalVersion00AndCreatesLocalChild() {
        TraceParent remote = TraceParent.parse(
                "00-4bf92f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-01").orElseThrow();

        TraceParent local = TraceParent.childOf(remote);

        assertThat(local.traceId()).isEqualTo(remote.traceId());
        assertThat(local.parentId()).matches("[0-9a-f]{16}")
                .isNotEqualTo(remote.parentId())
                .isNotEqualTo("0000000000000000");
        assertThat(local.traceFlags()).isEqualTo("01");
        assertThat(local.value()).hasSize(TraceParent.HEADER_LENGTH);
    }

    @Test
    void rejectsNonCanonicalUnsupportedAndZeroIdentifiers() {
        assertThat(TraceParent.parse(
                "00-4BF92F3577B34DA6A3CE929D0E0E4736-00f067aa0ba902b7-01")).isEmpty();
        assertThat(TraceParent.parse(
                "01-4bf92f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-01")).isEmpty();
        assertThat(TraceParent.parse(
                "00-00000000000000000000000000000000-00f067aa0ba902b7-01")).isEmpty();
        assertThat(TraceParent.parse(
                "00-4bf92f3577b34da6a3ce929d0e0e4736-0000000000000000-01")).isEmpty();
        assertThat(TraceParent.parse("x".repeat(10_000))).isEmpty();
    }

    @Test
    void createsCanonicalNonZeroRootAndNormalizesLegacyHex() {
        TraceParent root = TraceParent.newRoot("ABCDEF0123456789ABCDEF0123456789");

        assertThat(root.traceId()).isEqualTo("abcdef0123456789abcdef0123456789");
        assertThat(root.parentId()).matches("[0-9a-f]{16}").isNotEqualTo("0000000000000000");
        assertThat(root.value()).matches(
                "00-abcdef0123456789abcdef0123456789-[0-9a-f]{16}-00");
    }

    @Test
    void createsSampledOutboundChildForTrustedCurrentTrace() {
        TraceParent child = TraceParent.outboundChild("4BF92F3577B34DA6A3CE929D0E0E4736");

        assertThat(child.value()).matches(
                "00-4bf92f3577b34da6a3ce929d0e0e4736-[0-9a-f]{16}-01");
    }
}