use axum::http::{HeaderMap, HeaderValue};
use crank_observability::RequestId;
use uuid::Version;

#[test]
fn preserves_valid_opaque_request_id() {
    let request_id = RequestId::resolve(Some("req_test-123/abc"));

    assert_eq!(request_id.as_str(), "req_test-123/abc");
}

#[test]
fn replaces_missing_and_invalid_values_with_uuid_v7() {
    for candidate in [
        None,
        Some(""),
        Some("bad value"),
        Some(" leading"),
        Some("trailing "),
        Some("bad,value"),
        Some("bad;value"),
        Some("я"),
    ] {
        let request_id = RequestId::resolve(candidate);
        let parsed = uuid::Uuid::parse_str(request_id.as_str()).expect("generated UUID");

        assert_eq!(parsed.get_version(), Some(Version::SortRand));
    }
}

#[test]
fn rejects_values_over_the_shared_limit() {
    let oversized = "x".repeat(RequestId::MAX_LEN + 1);
    let request_id = RequestId::resolve(Some(&oversized));

    assert_ne!(request_id.as_str(), oversized);
    assert_eq!(
        uuid::Uuid::parse_str(request_id.as_str())
            .expect("generated UUID")
            .get_version(),
        Some(Version::SortRand)
    );
}

#[test]
fn resolves_exactly_one_header_value_and_rejects_ambiguous_values() {
    let mut single = HeaderMap::new();
    single.insert(
        "x-request-id",
        HeaderValue::from_static("opaque-request-id"),
    );

    assert_eq!(
        RequestId::resolve_from_headers(&single).as_str(),
        "opaque-request-id"
    );

    let mut ambiguous = HeaderMap::new();
    ambiguous.append("x-request-id", HeaderValue::from_static("first-request-id"));
    ambiguous.append(
        "x-request-id",
        HeaderValue::from_static("second-request-id"),
    );

    let generated = RequestId::resolve_from_headers(&ambiguous);
    assert_ne!(generated.as_str(), "first-request-id");
    assert_ne!(generated.as_str(), "second-request-id");
    assert_eq!(
        uuid::Uuid::parse_str(generated.as_str())
            .expect("generated UUID")
            .get_version(),
        Some(Version::SortRand)
    );
}