import asyncio
from unittest.mock import AsyncMock

import pytest

from gateway.config import GatewayConfig, Platform, PlatformConfig
from gateway.platforms.base import BasePlatformAdapter, MessageEvent, SendResult
from gateway.run import GatewayRunner
from gateway.session import SessionSource, build_session_key


class _FatalAdapter(BasePlatformAdapter):
    def __init__(self):
        super().__init__(PlatformConfig(enabled=True, token="token"), Platform.TELEGRAM)

    async def connect(self, *, is_reconnect: bool = False) -> bool:
        self._set_fatal_error(
            "telegram_token_lock",
            "Another local Hermes gateway is already using this Telegram bot token.",
            retryable=False,
        )
        return False

    async def disconnect(self) -> None:
        self._mark_disconnected()

    async def send(self, chat_id, content, reply_to=None, metadata=None):
        raise NotImplementedError

    async def get_chat_info(self, chat_id):
        return {"id": chat_id}


class _RuntimeRetryableAdapter(BasePlatformAdapter):
    def __init__(self):
        super().__init__(PlatformConfig(enabled=True, token="token"), Platform.WHATSAPP)

    async def connect(self, *, is_reconnect: bool = False) -> bool:
        return True

    async def disconnect(self) -> None:
        self._mark_disconnected()

    async def send(self, chat_id, content, reply_to=None, metadata=None):
        raise NotImplementedError

    async def get_chat_info(self, chat_id):
        return {"id": chat_id}


class _ReplacementDeliveryAdapter(BasePlatformAdapter):
    def __init__(self):
        super().__init__(
            PlatformConfig(enabled=True, token="token", typing_indicator=False),
            Platform.DISCORD,
        )
        self.sent: list[str] = []
        self.connected = True

    async def connect(self, *, is_reconnect: bool = False) -> bool:
        return True

    async def disconnect(self) -> None:
        self.connected = False

    async def send(self, chat_id, content, reply_to=None, metadata=None):
        if not self.connected:
            return SendResult(success=False, error="Not connected")
        self.sent.append(content)
        return SendResult(success=True, message_id=f"m-{len(self.sent)}")

    async def send_typing(self, chat_id, metadata=None) -> None:
        return None

    async def get_chat_info(self, chat_id):
        return {"id": chat_id}


@pytest.mark.asyncio
async def test_runner_queues_retryable_runtime_fatal_for_reconnection(monkeypatch, tmp_path):
    """Retryable runtime fatal errors queue the platform for reconnection
    AND keep the gateway alive — the background reconnect watcher recovers
    the platform when the underlying issue clears.  (Previously this
    exited-with-failure to trigger a systemd restart; that converted
    transient failures into infinite restart loops.)
    """
    config = GatewayConfig(
        platforms={
            Platform.WHATSAPP: PlatformConfig(enabled=True, token="token")
        },
        sessions_dir=tmp_path / "sessions",
    )
    runner = GatewayRunner(config)
    adapter = _RuntimeRetryableAdapter()
    adapter._set_fatal_error(
        "whatsapp_bridge_exited",
        "WhatsApp bridge process exited unexpectedly (code 1).",
        retryable=True,
    )

    runner.adapters = {Platform.WHATSAPP: adapter}
    runner.delivery_router.adapters = runner.adapters
    runner.stop = AsyncMock()

    await runner._handle_adapter_fatal_error(adapter)

    # Gateway stays alive — watcher will retry in background
    runner.stop.assert_not_awaited()
    assert runner._exit_with_failure is False
    assert Platform.WHATSAPP in runner._failed_platforms
    assert runner._failed_platforms[Platform.WHATSAPP]["attempts"] == 0


@pytest.mark.asyncio
async def test_retryable_fatal_queues_reconnect_after_cancellation_swallowing_disconnect(
    monkeypatch, tmp_path
):
    """A wedged old adapter cannot block runner-owned reconnect recovery."""
    monkeypatch.setenv("HERMES_GATEWAY_ADAPTER_DISCONNECT_TIMEOUT", "0.01")
    config = GatewayConfig(
        platforms={Platform.WHATSAPP: PlatformConfig(enabled=True, token="token")},
        sessions_dir=tmp_path / "sessions",
    )
    runner = GatewayRunner(config)
    adapter = _RuntimeRetryableAdapter()
    adapter._set_fatal_error("transport_stale", "transport stale", retryable=True)
    runner.adapters = {Platform.WHATSAPP: adapter}
    runner.delivery_router.adapters = runner.adapters

    started = asyncio.Event()
    release = asyncio.Event()
    finished = asyncio.Event()

    async def swallow_cancellation():
        started.set()
        while not release.is_set():
            try:
                await release.wait()
            except asyncio.CancelledError:
                continue
        finished.set()

    monkeypatch.setattr(adapter, "disconnect", swallow_cancellation)
    operation = asyncio.create_task(runner._handle_adapter_fatal_error(adapter))
    await started.wait()
    done, _pending = await asyncio.wait({operation}, timeout=0.2)
    try:
        assert operation in done
        assert runner.adapters == {}
        assert Platform.WHATSAPP in runner._failed_platforms
        assert runner._failed_platforms[Platform.WHATSAPP]["attempts"] == 0
    finally:
        release.set()
        await asyncio.wait({operation}, timeout=0.2)
        await asyncio.wait_for(finished.wait(), timeout=0.2)