import asyncio
import importlib
import logging
import logging.handlers
import traceback
from pathlib import Path
from typing import Final

import pytest
from starlette.types import Message, Scope
from uvicorn import config as uvicorn_config

from litellm.proxy.dev_reload import (
    RELOAD_OPTIONS,
    RELOAD_WORKER_HEALTHCHECK_SECONDS,
    ReloadOptions,
    load_app_or_exit,
    load_worker_app,
    multi_worker_reload_supported,
    pool_config,
)
from litellm.proxy.proxy_cli import ProxyInitializationHelpers

UNCHANGED_LOGGING: Final = {"version": 1, "incremental": True}
POOL_WORKERS: Final = 2
REQUIRES_UVICORN_STARTUP_FAILURE: Final = pytest.mark.skipif(
    not multi_worker_reload_supported(), reason="uvicorn<0.50.0 has no startup failure exit code"
)


def _options(app: str) -> ReloadOptions:
    return {
        "app": app,
        "log_config": UNCHANGED_LOGGING,
        "reload": True,
        "reload_dirs": (),
        "reload_includes": ("*.py",),
    }


@REQUIRES_UVICORN_STARTUP_FAILURE
@pytest.mark.parametrize(
    ("module", "source"),
    (
        ("reload_syntax_error_app", "def app(\n"),
        ("reload_name_error_app", "app = undefined_name\n"),
        ("reload_runtime_error_app", "raise RuntimeError('broken edit')\n"),
        ("reload_missing_attribute_app", "value = 1\n"),
    ),
)
def test_a_broken_app_exits_the_worker_as_a_startup_failure(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch, module: str, source: str
) -> None:
    (tmp_path / f"{module}.py").write_text(source)
    monkeypatch.syspath_prepend(str(tmp_path))
    with pytest.raises(SystemExit) as exit_info:
        pool_config(_options(f"{module}:app"), workers=2).load()
    assert exit_info.value.code == uvicorn_config.STARTUP_FAILURE


@REQUIRES_UVICORN_STARTUP_FAILURE
@pytest.mark.parametrize(
    ("module", "source"),
    (
        (
            "reload_factory_missing_module_app",
            "def factory():\n    import a_module_that_does_not_exist\n",
        ),
        (
            "reload_factory_runtime_error_app",
            "def factory():\n    raise RuntimeError('broken edit')\n",
        ),
    ),
)
def test_a_broken_factory_exits_the_worker_as_a_startup_failure(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch, module: str, source: str
) -> None:
    (tmp_path / f"{module}.py").write_text(source)
    monkeypatch.syspath_prepend(str(tmp_path))
    with pytest.raises(SystemExit) as exit_info:
        pool_config(
            _options(f"{module}:app"),
            workers=POOL_WORKERS,
            worker_overrides={"app": f"{module}:factory", "factory": True},
        ).load()
    assert exit_info.value.code == uvicorn_config.STARTUP_FAILURE


@REQUIRES_UVICORN_STARTUP_FAILURE
@pytest.mark.parametrize(
    ("module", "source"),
    (
        ("reload_import_error_app", "import os\nfrom os import missing_name\n"),
        ("reload_value_error_app", "import os\nraise ValueError('broken edit')\n"),
    ),
)
def test_a_broken_import_logs_the_line_that_raised(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch, module: str, source: str
) -> None:
    app_file: Final = tmp_path / f"{module}.py"
    app_file.write_text(source)
    monkeypatch.syspath_prepend(str(tmp_path))
    uvicorn_logger: Final = logging.getLogger("uvicorn.error")
    captured: Final = logging.handlers.BufferingHandler(capacity=POOL_WORKERS)
    uvicorn_logger.addHandler(captured)
    try:
        with pytest.raises(SystemExit):
            load_app_or_exit(f"{module}:app")
    finally:
        uvicorn_logger.removeHandler(captured)
    (record,) = captured.buffer
    assert record.exc_info is not None
    raised_at: Final = frozenset((frame.filename, frame.lineno) for frame in traceback.extract_tb(record.exc_info[2]))
    assert (str(app_file), 2) in raised_at, record.exc_text


def test_the_reload_pool_defaults_the_worker_healthcheck_and_keeps_an_explicit_one() -> None:
    explicit: Final = RELOAD_WORKER_HEALTHCHECK_SECONDS + 7
    assert pool_config(_options("app:app"), workers=2).timeout_worker_healthcheck == RELOAD_WORKER_HEALTHCHECK_SECONDS
    assert (
        pool_config({**_options("app:app"), "timeout_worker_healthcheck": explicit}, workers=2).timeout_worker_healthcheck
        == explicit
    )


def test_the_reload_pool_accepts_and_keeps_every_uvicorn_arg_the_proxy_cli_builds(tmp_path: Path) -> None:
    cli_args: Final = ProxyInitializationHelpers.get_default_unvicorn_init_args(
        "127.0.0.1", 4123, keepalive_timeout=61, timeout_worker_healthcheck=RELOAD_WORKER_HEALTHCHECK_SECONDS + 7
    )
    options: Final = RELOAD_OPTIONS.validate_python(
        {
            **cli_args,
            "log_config": UNCHANGED_LOGGING,
            "reload": True,
            "reload_dirs": [str(tmp_path)],
            "reload_includes": ["*.py"],
        }
    )
    config: Final = pool_config(options, workers=POOL_WORKERS)
    server_args: Final = {key: value for key, value in cli_args.items() if key not in ("app", "log_config")}
    assert {key: getattr(config, key) for key in server_args} == server_args


def test_the_reload_pool_passes_a_uvicorn_arg_it_does_not_list_through_to_the_workers() -> None:
    config: Final = pool_config(RELOAD_OPTIONS.validate_python({**_options("app:app"), "backlog": 123}), workers=POOL_WORKERS)
    assert (config.backlog, config.reload) == (123, False)


def test_the_reload_pool_serves_the_overridden_worker_app(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
    module: Final = "reload_worker_override_app"
    (tmp_path / f"{module}.py").write_text(
        "async def base_app(scope, receive, send):\n"
        "    await receive()\n"
        "    await send({'type': 'http.response.start', 'status': 200, 'headers': []})\n"
        "    await send({'type': 'http.response.body', 'body': b'base app', 'more_body': False})\n"
        "\n"
        "async def overridden_app(scope, receive, send):\n"
        "    await receive()\n"
        "    await send({'type': 'http.response.start', 'status': 200, 'headers': []})\n"
        "    await send({'type': 'http.response.body', 'body': b'overridden app', 'more_body': False})\n"
        "\n"
        "def base_factory():\n"
        "    return base_app\n"
        "\n"
        "def factory():\n"
        "    return overridden_app\n"
    )
    monkeypatch.syspath_prepend(str(tmp_path))
    config: Final = pool_config(
        _options(f"{module}:base_factory"),
        workers=POOL_WORKERS,
        worker_overrides={"app": f"{module}:factory", "factory": True, "log_config": None},
    )
    assert config.log_config is None
    config.load()
    loaded_app: Final = config.loaded_app
    assert loaded_app is not None
    scope: Final[Scope] = {"type": "http", "method": "GET", "path": "/", "headers": []}

    async def run_app() -> tuple[Message, ...]:
        messages: Final[asyncio.Queue[Message]] = asyncio.Queue()

        async def receive() -> Message:
            return {"type": "http.request", "body": b"", "more_body": False}

        async def send(message: Message) -> None:
            await messages.put(message)

        await loaded_app(scope, receive, send)
        return tuple(messages.get_nowait() for _ in range(messages.qsize()))

    messages: Final = asyncio.run(run_app())
    assert messages == (
        {"type": "http.response.start", "status": 200, "headers": []},
        {"type": "http.response.body", "body": b"overridden app", "more_body": False},
    )


def test_load_worker_app_calls_the_overridden_factory(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
    module: Final = "reload_worker_app_factory"
    (tmp_path / f"{module}.py").write_text(
        "def app(scope, receive, send):\n    return None\n\ndef factory():\n    return app\n"
    )
    monkeypatch.syspath_prepend(str(tmp_path))
    app: Final = importlib.import_module(module).app
    assert load_worker_app(f"{module}:factory", worker_app_factory=True) is app


def test_windows_keeps_single_worker_reload_whatever_the_uvicorn_version() -> None:
    assert not multi_worker_reload_supported("win32")


def test_a_working_app_loads_as_the_module_defines_it(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
    (tmp_path / "reload_working_app.py").write_text("async def app(scope, receive, send):\n    return None\n")
    monkeypatch.syspath_prepend(str(tmp_path))
    assert load_app_or_exit("reload_working_app:app") is importlib.import_module("reload_working_app").app