use super::super::common::build_test_app_with_external_references;
use super::*;
use std::{
    io,
    sync::{Arc, Mutex},
};

use metrics_util::debugging::DebuggingRecorder;
use opentelemetry::trace::TracerProvider as _;
use opentelemetry_sdk::{
    error::OTelSdkResult,
    trace::{SdkTracerProvider, SpanData, SpanExporter},
};
use tracing_subscriber::{fmt::MakeWriter, layer::SubscriberExt};

#[tokio::test(flavor = "multi_thread")]
#[serial]
async fn parser_canary_never_reaches_diagnostics_logs_traces_or_metrics() {
    const CANARY: &str = "openapi-telemetry-secret-canary";

    let recorder = DebuggingRecorder::new();
    let snapshotter = recorder.snapshotter();
    recorder
        .install()
        .expect("isolated integration test metrics recorder");

    let writer = SharedLogWriter::default();
    let exported = Arc::new(Mutex::new(Vec::new()));
    let provider = SdkTracerProvider::builder()
        .with_simple_exporter(CapturingExporter(Arc::clone(&exported)))
        .build();
    let tracer = provider.tracer("admin-openapi-source-test");
    let subscriber = tracing_subscriber::registry()
        .with(
            tracing_subscriber::fmt::layer()
                .with_ansi(false)
                .with_writer(writer.clone()),
        )
        .with(tracing_opentelemetry::layer().with_tracer(tracer));
    let dispatch = tracing::Dispatch::new(subscriber);
    tracing::dispatcher::set_global_default(dispatch)
        .expect("isolated integration test tracing subscriber");

    let registry = test_registry().await;
    let app = build_test_app(registry, test_storage_root("openapi_telemetry_canary"));
    let server = spawn_admin_api(app).await;
    let client = authorized_client(&server).await;
    let document = format!(
        "openapi: 3.0.3\ninfo: {{ title: Canary }}\npaths:\n  /broken:\n    get:\n      description: {CANARY}\n      responses: ["
    );
    let response = client
        .post(format!("{server}/imports/openapi/preview"))
        .multipart(Form::new().part(
            "file",
            file_part(document.as_bytes(), "openapi.yaml", "application/yaml"),
        ))
        .send()
        .await
        .unwrap();
    assert_eq!(response.status(), reqwest::StatusCode::BAD_REQUEST);
    let trace_id = response
        .headers()
        .get("x-trace-id")
        .unwrap()
        .to_str()
        .unwrap()
        .to_owned();
    let body = response.text().await.unwrap();
    assert!(!body.contains(CANARY));
    let diagnostics: Value = serde_json::from_str(&body).unwrap();
    assert_eq!(diagnostics["error"]["trace_id"], trace_id);

    let route = format!("/{CANARY}.yaml");
    let external = axum::Router::new().route(
        &route,
        axum::routing::get(|| async { (axum::http::StatusCode::INTERNAL_SERVER_ERROR, CANARY) }),
    );
    let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
    let address = listener.local_addr().unwrap();
    tokio::spawn(async move { axum::serve(listener, external).await.unwrap() });
    let origin = format!("http://{address}");
    let external_registry = test_registry().await;
    let external_app = build_test_app_with_external_references(
        external_registry,
        test_storage_root("openapi_materialization_telemetry_canary"),
        vec![format!("{origin}/")],
    );
    let external_server = spawn_admin_api(external_app).await;
    let external_client = authorized_client(&external_server).await;
    let external_document = format!(
        r#"
openapi: 3.1.0
info: {{ title: Safe materialization }}
servers: [{{ url: https://api.example.test }}]
paths:
  /items:
    get:
      responses:
        '200':
          description: ok
          content:
            application/json:
              schema: {{ $ref: '{origin}/{CANARY}.yaml#/Item' }}
"#
    );
    let response = external_client
        .post(format!("{external_server}/imports/openapi/preview"))
        .multipart(Form::new().part(
            "file",
            file_part(
                external_document.as_bytes(),
                "external.yaml",
                "application/yaml",
            ),
        ))
        .send()
        .await
        .unwrap();
    assert_eq!(response.status(), reqwest::StatusCode::OK);

    provider.force_flush().unwrap();
    let logs = writer.output();
    assert!(!logs.contains(CANARY));
    assert!(logs.contains(&trace_id));
    let safe_materialization_failure = logs.lines().any(is_safe_materialization_failure);
    assert!(
        safe_materialization_failure,
        "expected one bounded, sanitized materialization failure"
    );
    let spans = exported.lock().unwrap();
    let rendered_spans = format!("{spans:?}");
    assert!(!rendered_spans.contains(CANARY));
    drop(spans);
    for (key, _, _, _) in snapshotter.snapshot().into_vec() {
        assert!(!key.key().name().contains(CANARY));
        assert!(
            !key.key()
                .labels()
                .any(|label| { label.key().contains(CANARY) || label.value().contains(CANARY) })
        );
    }
    provider.shutdown().unwrap();
}

fn is_safe_materialization_failure(line: &str) -> bool {
    if !line.contains("external OpenAPI materialization failed") || !line.contains("count=0") {
        return false;
    }
    let immediate_status = contains_log_field(line, "stage", "fetch")
        && contains_log_field(line, "error_code", "unexpected_status");
    let bounded_timeout = contains_log_field(line, "stage", "chain")
        && contains_log_field(line, "error_code", "timeout");
    immediate_status || bounded_timeout
}

fn contains_log_field(line: &str, name: &str, value: &str) -> bool {
    line.contains(&format!("{name}=\"{value}\"")) || line.contains(&format!("{name}={value}"))
}

#[test]
fn materialization_log_accepts_only_coherent_safe_outcomes() {
    for line in [
        r#"external OpenAPI materialization failed stage="fetch" error_code="unexpected_status" count=0"#,
        "external OpenAPI materialization failed stage=chain error_code=timeout count=0",
    ] {
        assert!(is_safe_materialization_failure(line));
    }
    assert!(!is_safe_materialization_failure(
        r#"external OpenAPI materialization failed stage="fetch" error_code="timeout" count=0"#
    ));
}

#[derive(Clone, Default)]
struct SharedLogWriter {
    buffer: Arc<Mutex<Vec<u8>>>,
}

impl SharedLogWriter {
    fn output(&self) -> String {
        String::from_utf8(self.buffer.lock().unwrap().clone()).unwrap()
    }
}

impl<'a> MakeWriter<'a> for SharedLogWriter {
    type Writer = SharedLogGuard;

    fn make_writer(&'a self) -> Self::Writer {
        SharedLogGuard {
            buffer: Arc::clone(&self.buffer),
            pending: Vec::new(),
        }
    }
}

struct SharedLogGuard {
    buffer: Arc<Mutex<Vec<u8>>>,
    pending: Vec<u8>,
}

impl io::Write for SharedLogGuard {
    fn write(&mut self, bytes: &[u8]) -> io::Result<usize> {
        self.pending.extend_from_slice(bytes);
        Ok(bytes.len())
    }

    fn flush(&mut self) -> io::Result<()> {
        Ok(())
    }
}

impl Drop for SharedLogGuard {
    fn drop(&mut self) {
        self.buffer.lock().unwrap().extend_from_slice(&self.pending);
    }
}

#[test]
fn shared_log_writer_publishes_complete_records_only() {
    let writer = SharedLogWriter::default();
    let mut guard = writer.make_writer();
    io::Write::write_all(&mut guard, b"message").unwrap();
    assert!(writer.output().is_empty());

    io::Write::write_all(&mut guard, b" stage=\"fetch\"\n").unwrap();
    drop(guard);
    assert_eq!(writer.output(), "message stage=\"fetch\"\n");
}

#[derive(Clone, Debug)]
struct CapturingExporter(Arc<Mutex<Vec<SpanData>>>);

impl SpanExporter for CapturingExporter {
    async fn export(&self, batch: Vec<SpanData>) -> OTelSdkResult {
        self.0.lock().unwrap().extend(batch);
        Ok(())
    }
}