"""Tests for the pure-ASGI ingress correlation owner."""

import asyncio
from collections.abc import Iterator
from contextlib import contextmanager
from typing import cast
from unittest.mock import patch

import pytest
from fastapi import Request
from starlette.datastructures import Headers
from starlette.middleware.base import BaseHTTPMiddleware
from starlette.types import ASGIApp, Message, Scope

from free_claude_code.api.request_ids import (
    RequestCorrelationMiddleware,
    get_request_id,
)
from tests.api.support import create_test_app


def _http_scope(path: str) -> Scope:
    return cast(
        Scope,
        {
            "type": "http",
            "asgi": {"version": "3.0", "spec_version": "2.4"},
            "http_version": "1.1",
            "method": "POST",
            "scheme": "http",
            "path": path,
            "raw_path": path.encode(),
            "query_string": b"",
            "headers": [(b"anthropic-session-id", b"session_test")],
            "client": None,
            "server": None,
        },
    )


def test_application_uses_the_pure_asgi_correlation_owner() -> None:
    app = create_test_app()
    middleware_classes = [middleware.cls for middleware in app.user_middleware]

    assert sum(cls is RequestCorrelationMiddleware for cls in middleware_classes) == 1
    assert all(cls is not BaseHTTPMiddleware for cls in middleware_classes)


@pytest.mark.asyncio
async def test_correlation_context_and_headers_span_the_complete_stream() -> None:
    response_started = asyncio.Event()
    allow_body = asyncio.Event()
    sent: list[Message] = []
    context_entries: list[dict[str, object]] = []
    context_exits: list[dict[str, object]] = []
    app_request_id: str | None = None

    async def app(scope: Scope, _receive, send) -> None:
        nonlocal app_request_id
        app_request_id = get_request_id(Request(scope))
        await send(
            {
                "type": "http.response.start",
                "status": 200,
                "headers": [],
            }
        )
        response_started.set()
        await allow_body.wait()
        await send(
            {
                "type": "http.response.body",
                "body": b"done",
                "more_body": False,
            }
        )

    @contextmanager
    def contextualize(**fields: object) -> Iterator[None]:
        context_entries.append(fields)
        try:
            yield
        finally:
            context_exits.append(fields)

    async def receive() -> Message:
        raise AssertionError("Test application does not receive messages")

    async def send(message: Message) -> None:
        sent.append(message)

    middleware = RequestCorrelationMiddleware(cast(ASGIApp, app))
    with patch(
        "free_claude_code.api.request_ids.logger.contextualize",
        side_effect=contextualize,
    ):
        request = asyncio.create_task(
            middleware(_http_scope("/v1/responses"), receive, send)
        )
        await response_started.wait()

        assert context_exits == []
        assert app_request_id is not None
        headers = Headers(raw=sent[0]["headers"])
        assert headers["request-id"] == app_request_id
        assert headers["x-request-id"] == app_request_id
        assert context_entries == [
            {
                "http_method": "POST",
                "http_path": "/v1/responses",
                "claude_session_id": "session_test",
                "request_id": app_request_id,
            }
        ]

        allow_body.set()
        await request

    assert context_exits == context_entries


@pytest.mark.asyncio
async def test_correlation_middleware_passes_non_http_scopes_unchanged() -> None:
    observed_scope: Scope | None = None

    async def app(scope: Scope, _receive, _send) -> None:
        nonlocal observed_scope
        observed_scope = scope

    async def receive() -> Message:
        return {"type": "lifespan.startup"}

    async def send(_message: Message) -> None:
        return None

    scope = cast(Scope, {"type": "lifespan", "asgi": {"version": "3.0"}})
    await RequestCorrelationMiddleware(cast(ASGIApp, app))(scope, receive, send)

    assert observed_scope is scope
    assert "state" not in scope