"""``kilostar.utils.request_context``：双层 ID 的 contextvars 与 logger 集成。

覆盖：

- ``request_id`` / ``trace_id`` 默认空、bind 后可读、reset 后还原
- ``request_id_scope`` / ``trace_id_scope`` 上下文管理器
- ``snapshot`` / ``apply_snapshot`` 跨边界透传
- logger 切面：``contextvars`` 中的值会自动写入 ``record["extra"]``
"""

from __future__ import annotations

import asyncio

import pytest

from kilostar.utils import request_context as rc


def test_default_values_are_empty():
    assert rc.get_request_id() == ""
    assert rc.get_trace_id() == ""


def test_bind_and_reset_request_id():
    token = rc.bind_request_id("req-abc")
    try:
        assert rc.get_request_id() == "req-abc"
    finally:
        rc.reset_request_id(token)
    assert rc.get_request_id() == ""


def test_bind_and_reset_trace_id():
    token = rc.bind_trace_id("trace-xyz")
    try:
        assert rc.get_trace_id() == "trace-xyz"
    finally:
        rc.reset_trace_id(token)
    assert rc.get_trace_id() == ""


def test_request_id_scope():
    with rc.request_id_scope("req-1") as rid:
        assert rid == "req-1"
        assert rc.get_request_id() == "req-1"
    assert rc.get_request_id() == ""


def test_trace_id_scope_nested():
    with rc.trace_id_scope("outer"):
        assert rc.get_trace_id() == "outer"
        with rc.trace_id_scope("inner"):
            assert rc.get_trace_id() == "inner"
        assert rc.get_trace_id() == "outer"
    assert rc.get_trace_id() == ""


def test_snapshot_returns_current_ids():
    with rc.request_id_scope("r1"), rc.trace_id_scope("t1"):
        snap = rc.snapshot()
        assert snap == {"request_id": "r1", "trace_id": "t1"}


def test_apply_snapshot_restores_after_exit():
    snap = {"request_id": "r2", "trace_id": "t2"}
    with rc.apply_snapshot(snap):
        assert rc.get_request_id() == "r2"
        assert rc.get_trace_id() == "t2"
    assert rc.get_request_id() == ""
    assert rc.get_trace_id() == ""


def test_apply_snapshot_handles_none():
    """传 None 应是 no-op，不报错。"""
    with rc.apply_snapshot(None):
        assert rc.get_request_id() == ""


@pytest.mark.asyncio
async def test_contextvars_isolated_between_concurrent_tasks():
    """两个并发的 asyncio task 各自的 trace_id 不应互相串味。"""
    results: dict[str, str] = {}

    async def worker(name: str, trace_id: str) -> None:
        with rc.trace_id_scope(trace_id):
            await asyncio.sleep(0)
            results[name] = rc.get_trace_id()

    await asyncio.gather(
        worker("a", "trace-a"),
        worker("b", "trace-b"),
    )
    assert results == {"a": "trace-a", "b": "trace-b"}


def test_new_request_id_format():
    rid = rc.new_request_id()
    assert rid.startswith("req-")
    assert len(rid) > len("req-")


def test_new_request_id_custom_prefix():
    rid = rc.new_request_id("ws")
    assert rid.startswith("ws-")