"""Unit tests for SocketEndpoint graceful shutdown functionality.

These tests exercise SocketEndpoint in its handshake-auth
configuration (``in_band_auth=False``) — the mode used in production
for the flow import/export streaming endpoints.  The mux socket at
``/api/v1/socket`` uses ``in_band_auth=True`` instead, where the
handshake always accepts and authentication runs on the first
WebSocket frame; that path is covered by the Mux tests.

Every endpoint constructor here passes an explicit capability — no
permissive default is relied upon.
"""

import pytest
import asyncio
from unittest.mock import AsyncMock, MagicMock, patch
from aiohttp import web, WSMsgType
from trustgraph.gateway.endpoint.socket import SocketEndpoint
from trustgraph.gateway.running import Running
from trustgraph.gateway.auth import Identity


# Representative capability used across these tests — corresponds to
# the flow-import streaming endpoint pattern that uses this class.
TEST_CAP = "graph:write"


def _valid_identity():
    return Identity(
        handle="test-user",
        workspace="default",
        principal_id="test-user",
        source="api-key",
    )


@pytest.fixture
def mock_auth():
    """Mock IAM-backed authenticator.  Successful by default —
    ``authenticate`` returns a valid identity and ``authorise``
    allows everything.  Tests that need the failure paths override
    the relevant attribute locally."""
    auth = MagicMock()
    auth.authenticate = AsyncMock(return_value=_valid_identity())
    auth.authorise = AsyncMock(return_value=None)
    return auth


@pytest.fixture
def mock_dispatcher_factory():
    """Mock dispatcher factory function."""
    async def dispatcher_factory(ws, running, match_info):
        dispatcher = AsyncMock()
        dispatcher.run = AsyncMock()
        dispatcher.receive = AsyncMock()
        dispatcher.destroy = AsyncMock()
        return dispatcher

    return dispatcher_factory


@pytest.fixture
def socket_endpoint(mock_auth, mock_dispatcher_factory):
    """Create SocketEndpoint for testing."""
    return SocketEndpoint(
        endpoint_path="/test-socket",
        auth=mock_auth,
        dispatcher=mock_dispatcher_factory,
        capability=TEST_CAP,
    )


@pytest.fixture
def mock_websocket():
    """Mock websocket response."""
    ws = AsyncMock(spec=web.WebSocketResponse)
    ws.prepare = AsyncMock()
    ws.close = AsyncMock()
    ws.closed = False
    return ws


@pytest.fixture
def mock_request():
    """Mock HTTP request."""
    request = MagicMock()
    request.query = {"token": "test-token"}
    request.match_info = {}
    return request


@pytest.mark.asyncio
async def test_listener_graceful_shutdown_on_close():
    """Test listener handles websocket close gracefully."""
    socket_endpoint = SocketEndpoint(
        "/test", MagicMock(), AsyncMock(),
        capability=TEST_CAP,
    )
    
    # Mock websocket that closes after one message
    ws = AsyncMock()
    
    # Create async iterator that yields one message then closes
    async def mock_iterator(self):
        # Yield normal message
        msg = MagicMock()
        msg.type = WSMsgType.TEXT
        yield msg
        
        # Yield close message 
        close_msg = MagicMock()
        close_msg.type = WSMsgType.CLOSE
        yield close_msg
    
    # Set the async iterator method
    ws.__aiter__ = mock_iterator
    
    dispatcher = AsyncMock()
    running = Running()
    
    with patch('asyncio.sleep') as mock_sleep:
        await socket_endpoint.listener(ws, dispatcher, running)
    
    # Should have processed one message
    dispatcher.receive.assert_called_once()
    
    # Should have initiated graceful shutdown
    assert running.get() is False
    
    # Should have slept for grace period
    mock_sleep.assert_called_once_with(1.0)


@pytest.mark.asyncio
async def test_handle_normal_flow():
    """Valid bearer → handshake accepted, dispatcher created."""
    mock_auth = MagicMock()
    mock_auth.authenticate = AsyncMock(return_value=_valid_identity())
    mock_auth.authorise = AsyncMock(return_value=None)

    dispatcher_created = False
    async def mock_dispatcher_factory(ws, running, match_info):
        nonlocal dispatcher_created
        dispatcher_created = True
        dispatcher = AsyncMock()
        dispatcher.destroy = AsyncMock()
        return dispatcher

    socket_endpoint = SocketEndpoint(
        "/test", mock_auth, mock_dispatcher_factory,
        capability=TEST_CAP,
    )

    request = MagicMock()
    request.query = {"token": "valid-token"}
    request.match_info = {}

    with patch('aiohttp.web.WebSocketResponse') as mock_ws_class:
        mock_ws = AsyncMock()
        mock_ws.prepare = AsyncMock()
        mock_ws.close = AsyncMock()
        mock_ws.closed = False
        mock_ws_class.return_value = mock_ws

        with patch('asyncio.TaskGroup') as mock_task_group:
            # Mock task group context manager
            mock_tg = AsyncMock()
            mock_tg.__aenter__ = AsyncMock(return_value=mock_tg)
            mock_tg.__aexit__ = AsyncMock(return_value=None)

            # Create proper mock tasks that look like asyncio.Task objects
            def create_task_mock(coro):
                # Consume the coroutine to avoid "was never awaited" warning
                coro.close()
                task = AsyncMock()
                task.done = MagicMock(return_value=True)
                task.cancelled = MagicMock(return_value=False)
                return task

            mock_tg.create_task = MagicMock(side_effect=create_task_mock)
            mock_task_group.return_value = mock_tg

            result = await socket_endpoint.handle(request)

    # Should have created dispatcher
    assert dispatcher_created is True

    # Should return websocket
    assert result == mock_ws


@pytest.mark.asyncio
async def test_handle_exception_group_cleanup():
    """Test exception group triggers dispatcher cleanup."""
    mock_auth = MagicMock()
    mock_auth.authenticate = AsyncMock(return_value=_valid_identity())
    mock_auth.authorise = AsyncMock(return_value=None)

    mock_dispatcher = AsyncMock()
    mock_dispatcher.destroy = AsyncMock()

    async def mock_dispatcher_factory(ws, running, match_info):
        return mock_dispatcher

    socket_endpoint = SocketEndpoint(
        "/test", mock_auth, mock_dispatcher_factory,
        capability=TEST_CAP,
    )

    request = MagicMock()
    request.query = {"token": "valid-token"}
    request.match_info = {}

    # Mock TaskGroup to raise ExceptionGroup
    class TestException(Exception):
        pass

    exception_group = ExceptionGroup("Test exceptions", [TestException("test")])

    with patch('aiohttp.web.WebSocketResponse') as mock_ws_class:
        mock_ws = AsyncMock()
        mock_ws.prepare = AsyncMock()
        mock_ws.close = AsyncMock()
        mock_ws.closed = False
        mock_ws_class.return_value = mock_ws

        with patch('asyncio.TaskGroup') as mock_task_group:
            mock_tg = AsyncMock()
            mock_tg.__aenter__ = AsyncMock(return_value=mock_tg)
            mock_tg.__aexit__ = AsyncMock(side_effect=exception_group)

            # Create proper mock tasks that look like asyncio.Task objects
            def create_task_mock(coro):
                # Consume the coroutine to avoid "was never awaited" warning
                coro.close()
                task = AsyncMock()
                task.done = MagicMock(return_value=True)
                task.cancelled = MagicMock(return_value=False)
                return task

            mock_tg.create_task = MagicMock(side_effect=create_task_mock)
            mock_task_group.return_value = mock_tg

            with patch('trustgraph.gateway.endpoint.socket.asyncio.wait_for', new_callable=AsyncMock) as mock_wait_for:
                # Make wait_for consume the coroutine passed to it
                async def wait_for_side_effect(coro, timeout=None):
                    coro.close()  # Consume the coroutine
                    return None
                mock_wait_for.side_effect = wait_for_side_effect

                result = await socket_endpoint.handle(request)

    # Should have attempted graceful cleanup
    mock_wait_for.assert_called_once()

    # Should have called destroy in finally block
    assert mock_dispatcher.destroy.call_count >= 1

    # Should have closed websocket
    mock_ws.close.assert_called()


@pytest.mark.asyncio
async def test_handle_dispatcher_cleanup_timeout():
    """Test dispatcher cleanup with timeout."""
    mock_auth = MagicMock()
    mock_auth.authenticate = AsyncMock(return_value=_valid_identity())
    mock_auth.authorise = AsyncMock(return_value=None)

    # Mock dispatcher that takes long to destroy
    mock_dispatcher = AsyncMock()
    mock_dispatcher.destroy = AsyncMock()

    async def mock_dispatcher_factory(ws, running, match_info):
        return mock_dispatcher

    socket_endpoint = SocketEndpoint(
        "/test", mock_auth, mock_dispatcher_factory,
        capability=TEST_CAP,
    )

    request = MagicMock()
    request.query = {"token": "valid-token"}
    request.match_info = {}

    # Mock TaskGroup to raise exception
    exception_group = ExceptionGroup("Test", [Exception("test")])

    with patch('aiohttp.web.WebSocketResponse') as mock_ws_class:
        mock_ws = AsyncMock()
        mock_ws.prepare = AsyncMock()
        mock_ws.close = AsyncMock()
        mock_ws.closed = False
        mock_ws_class.return_value = mock_ws

        with patch('asyncio.TaskGroup') as mock_task_group:
            mock_tg = AsyncMock()
            mock_tg.__aenter__ = AsyncMock(return_value=mock_tg)
            mock_tg.__aexit__ = AsyncMock(side_effect=exception_group)

            # Create proper mock tasks that look like asyncio.Task objects
            def create_task_mock(coro):
                # Consume the coroutine to avoid "was never awaited" warning
                coro.close()
                task = AsyncMock()
                task.done = MagicMock(return_value=True)
                task.cancelled = MagicMock(return_value=False)
                return task

            mock_tg.create_task = MagicMock(side_effect=create_task_mock)
            mock_task_group.return_value = mock_tg

            # Mock asyncio.wait_for to raise TimeoutError
            with patch('trustgraph.gateway.endpoint.socket.asyncio.wait_for', new_callable=AsyncMock) as mock_wait_for:
                # Make wait_for consume the coroutine before raising
                async def wait_for_timeout(coro, timeout=None):
                    coro.close()  # Consume the coroutine
                    raise asyncio.TimeoutError("Cleanup timeout")
                mock_wait_for.side_effect = wait_for_timeout

                result = await socket_endpoint.handle(request)

    # Should have attempted cleanup with timeout
    mock_wait_for.assert_called_once()
    # Check that timeout was passed correctly
    assert mock_wait_for.call_args[1]['timeout'] == 5.0

    # Should still call destroy in finally block
    assert mock_dispatcher.destroy.call_count >= 1


@pytest.mark.asyncio
async def test_handle_unauthorized_request():
    """A bearer that the IAM layer rejects causes the handshake to
    fail with 401.  IamAuth surfaces an HTTPUnauthorized; the
    endpoint propagates it.  Note that the endpoint intentionally
    does NOT distinguish 'bad token', 'expired', 'revoked', etc. —
    that's the IAM error-masking policy."""
    mock_auth = MagicMock()
    mock_auth.authenticate = AsyncMock(side_effect=web.HTTPUnauthorized(
        text='{"error":"auth failure"}',
        content_type="application/json",
    ))

    socket_endpoint = SocketEndpoint(
        "/test", mock_auth, AsyncMock(),
        capability=TEST_CAP,
    )

    request = MagicMock()
    request.query = {"token": "invalid-token"}

    result = await socket_endpoint.handle(request)

    assert isinstance(result, web.HTTPUnauthorized)
    # authenticate must have been invoked with a synthetic request
    # carrying Bearer <the-token>.  The endpoint wraps the query-
    # string token into an Authorization header for a uniform auth
    # path — the IAM layer does not look at query strings directly.
    mock_auth.authenticate.assert_called_once()
    passed_req = mock_auth.authenticate.call_args.args[0]
    assert passed_req.headers["Authorization"] == "Bearer invalid-token"


@pytest.mark.asyncio
async def test_handle_missing_token():
    """Request with no ``token`` query param → 401 before any
    IAM call is made (cheap short-circuit)."""
    mock_auth = MagicMock()
    mock_auth.authenticate = AsyncMock(
        side_effect=AssertionError(
            "authenticate must not be invoked when no token is present"
        ),
    )

    socket_endpoint = SocketEndpoint(
        "/test", mock_auth, AsyncMock(),
        capability=TEST_CAP,
    )

    request = MagicMock()
    request.query = {}  # No token

    result = await socket_endpoint.handle(request)

    assert isinstance(result, web.HTTPUnauthorized)
    mock_auth.authenticate.assert_not_called()


@pytest.mark.asyncio
async def test_handle_websocket_already_closed():
    """Test handling when websocket is already closed."""
    mock_auth = MagicMock()
    mock_auth.authenticate = AsyncMock(return_value=_valid_identity())
    mock_auth.authorise = AsyncMock(return_value=None)

    mock_dispatcher = AsyncMock()
    mock_dispatcher.destroy = AsyncMock()

    async def mock_dispatcher_factory(ws, running, match_info):
        return mock_dispatcher

    socket_endpoint = SocketEndpoint(
        "/test", mock_auth, mock_dispatcher_factory,
        capability=TEST_CAP,
    )

    request = MagicMock()
    request.query = {"token": "valid-token"}
    request.match_info = {}

    with patch('aiohttp.web.WebSocketResponse') as mock_ws_class:
        mock_ws = AsyncMock()
        mock_ws.prepare = AsyncMock()
        mock_ws.close = AsyncMock()
        mock_ws.closed = True  # Already closed
        mock_ws_class.return_value = mock_ws

        with patch('asyncio.TaskGroup') as mock_task_group:
            mock_tg = AsyncMock()
            mock_tg.__aenter__ = AsyncMock(return_value=mock_tg)
            mock_tg.__aexit__ = AsyncMock(return_value=None)

            # Create proper mock tasks that look like asyncio.Task objects
            def create_task_mock(coro):
                # Consume the coroutine to avoid "was never awaited" warning
                coro.close()
                task = AsyncMock()
                task.done = MagicMock(return_value=True)
                task.cancelled = MagicMock(return_value=False)
                return task

            mock_tg.create_task = MagicMock(side_effect=create_task_mock)
            mock_task_group.return_value = mock_tg

            result = await socket_endpoint.handle(request)

    # Should still have called destroy
    mock_dispatcher.destroy.assert_called()

    # Should not attempt to close already closed websocket
    mock_ws.close.assert_not_called()  # Not called in finally since ws.closed = True