"""Tests for Telegram send() thread_id fallback.

When message_thread_id points to a non-existent thread, Telegram returns
BadRequest('Message thread not found'). Since BadRequest is a subclass of
NetworkError in python-telegram-bot, the old retry loop treated this as a
transient error and retried 3 times before silently failing — killing all
tool progress messages, streaming responses, and typing indicators.

The fix detects "thread not found" BadRequest errors and retries the send
WITHOUT message_thread_id so the message still reaches the chat.
"""

import sys
import types
from types import SimpleNamespace

import pytest

from gateway.config import PlatformConfig, Platform
from gateway.platforms.base import SendResult


# ── Fake telegram.error hierarchy ──────────────────────────────────────
# Mirrors the real python-telegram-bot hierarchy:
#   BadRequest → NetworkError → TelegramError → Exception


class FakeNetworkError(Exception):
    pass


class FakeBadRequest(FakeNetworkError):
    pass


class FakeTimedOut(FakeNetworkError):
    pass


class FakeRetryAfter(Exception):
    def __init__(self, seconds):
        super().__init__(f"Retry after {seconds}")
        self.retry_after = seconds


# Build a fake telegram module tree so the adapter's internal imports work
_fake_telegram = types.ModuleType("telegram")
_fake_telegram.Update = object
_fake_telegram.Bot = object
_fake_telegram.Message = object
_fake_telegram.InlineKeyboardButton = object
_fake_telegram.InlineKeyboardMarkup = object
_fake_telegram_error = types.ModuleType("telegram.error")
_fake_telegram_error.NetworkError = FakeNetworkError
_fake_telegram_error.BadRequest = FakeBadRequest
_fake_telegram_error.TimedOut = FakeTimedOut
_fake_telegram.error = _fake_telegram_error
_fake_telegram_constants = types.ModuleType("telegram.constants")
_fake_telegram_constants.ParseMode = SimpleNamespace(MARKDOWN_V2="MarkdownV2")
_fake_telegram_constants.ChatType = SimpleNamespace(
    GROUP="group",
    SUPERGROUP="supergroup",
    CHANNEL="channel",
)
_fake_telegram.constants = _fake_telegram_constants
_fake_telegram_ext = types.ModuleType("telegram.ext")
_fake_telegram_ext.Application = object
_fake_telegram_ext.CommandHandler = object
_fake_telegram_ext.CallbackQueryHandler = object
_fake_telegram_ext.MessageHandler = object
_fake_telegram_ext.ContextTypes = SimpleNamespace(DEFAULT_TYPE=object)
_fake_telegram_ext.filters = object
_fake_telegram_request = types.ModuleType("telegram.request")
_fake_telegram_request.HTTPXRequest = object


@pytest.fixture(autouse=True)
def _inject_fake_telegram(monkeypatch):
    """Inject fake telegram modules so the adapter can import from them."""
    monkeypatch.setitem(sys.modules, "telegram", _fake_telegram)
    monkeypatch.setitem(sys.modules, "telegram.error", _fake_telegram_error)
    monkeypatch.setitem(sys.modules, "telegram.constants", _fake_telegram_constants)
    monkeypatch.setitem(sys.modules, "telegram.ext", _fake_telegram_ext)
    monkeypatch.setitem(sys.modules, "telegram.request", _fake_telegram_request)


def _make_adapter():
    from gateway.platforms.telegram import TelegramAdapter

    config = PlatformConfig(enabled=True, token="fake-token")
    adapter = object.__new__(TelegramAdapter)
    adapter.config = config
    adapter._config = config
    adapter._platform = Platform.TELEGRAM
    adapter._connected = True
    adapter._dm_topics = {}
    adapter._dm_topics_config = []
    adapter._reply_to_mode = "first"
    adapter._fallback_ips = []
    adapter._polling_conflict_count = 0
    adapter._polling_network_error_count = 0
    adapter._polling_error_callback_ref = None
    adapter.platform = Platform.TELEGRAM
    return adapter


def test_forum_general_topic_without_message_thread_id_keeps_thread_context():
    """Forum General-topic messages should keep synthetic thread context."""
    from gateway.platforms import telegram as telegram_mod

    adapter = _make_adapter()
    message = SimpleNamespace(
        text="hello from General",
        caption=None,
        chat=SimpleNamespace(
            id=-100123,
            type=telegram_mod.ChatType.SUPERGROUP,
            is_forum=True,
            title="Forum group",
        ),
        from_user=SimpleNamespace(id=456, full_name="Alice"),
        message_thread_id=None,
        reply_to_message=None,
        message_id=10,
        date=None,
    )

    event = adapter._build_message_event(message, msg_type=SimpleNamespace(value="text"))

    assert event.source.chat_id == "-100123"
    assert event.source.chat_type == "group"
    assert event.source.thread_id == "1"


@pytest.mark.asyncio
async def test_send_omits_general_topic_thread_id():
    """Telegram sends to forum General should omit message_thread_id=1."""
    adapter = _make_adapter()
    call_log = []

    async def mock_send_message(**kwargs):
        call_log.append(dict(kwargs))
        return SimpleNamespace(message_id=42)

    adapter._bot = SimpleNamespace(send_message=mock_send_message)

    result = await adapter.send(
        chat_id="-100123",
        content="test message",
        metadata={"thread_id": "1"},
    )

    assert result.success is True
    assert len(call_log) == 1
    assert call_log[0]["chat_id"] == -100123
    assert call_log[0]["text"] == "test message"
    assert call_log[0]["reply_to_message_id"] is None
    assert call_log[0]["message_thread_id"] is None


@pytest.mark.asyncio
async def test_send_typing_retries_without_general_thread_when_not_found():
    """Typing for forum General should fall back if Telegram rejects thread 1."""
    adapter = _make_adapter()
    call_log = []

    async def mock_send_chat_action(**kwargs):
        call_log.append(dict(kwargs))
        if kwargs.get("message_thread_id") == 1:
            raise FakeBadRequest("Message thread not found")

    adapter._bot = SimpleNamespace(send_chat_action=mock_send_chat_action)

    await adapter.send_typing("-100123", metadata={"thread_id": "1"})

    assert call_log == [
        {"chat_id": -100123, "action": "typing", "message_thread_id": 1},
        {"chat_id": -100123, "action": "typing", "message_thread_id": None},
    ]


@pytest.mark.asyncio
async def test_send_retries_without_thread_on_thread_not_found():
    """When message_thread_id causes 'thread not found', retry without it."""
    adapter = _make_adapter()

    call_log = []

    async def mock_send_message(**kwargs):
        call_log.append(dict(kwargs))
        tid = kwargs.get("message_thread_id")
        if tid is not None:
            raise FakeBadRequest("Message thread not found")
        return SimpleNamespace(message_id=42)

    adapter._bot = SimpleNamespace(send_message=mock_send_message)

    result = await adapter.send(
        chat_id="123",
        content="test message",
        metadata={"thread_id": "99999"},
    )

    assert result.success is True
    assert result.message_id == "42"
    # First call has thread_id, second call retries without
    assert len(call_log) == 2
    assert call_log[0]["message_thread_id"] == 99999
    assert call_log[1]["message_thread_id"] is None


@pytest.mark.asyncio
async def test_send_raises_on_other_bad_request():
    """Non-thread BadRequest errors should NOT be retried — they fail immediately."""
    adapter = _make_adapter()

    async def mock_send_message(**kwargs):
        raise FakeBadRequest("Chat not found")

    adapter._bot = SimpleNamespace(send_message=mock_send_message)

    result = await adapter.send(
        chat_id="123",
        content="test message",
        metadata={"thread_id": "99999"},
    )

    assert result.success is False
    assert "Chat not found" in result.error


@pytest.mark.asyncio
async def test_send_without_thread_id_unaffected():
    """Normal sends without thread_id should work as before."""
    adapter = _make_adapter()

    call_log = []

    async def mock_send_message(**kwargs):
        call_log.append(dict(kwargs))
        return SimpleNamespace(message_id=100)

    adapter._bot = SimpleNamespace(send_message=mock_send_message)

    result = await adapter.send(
        chat_id="123",
        content="test message",
    )

    assert result.success is True
    assert len(call_log) == 1
    assert call_log[0]["message_thread_id"] is None


@pytest.mark.asyncio
async def test_send_retries_network_errors_normally():
    """Real transient network errors (not BadRequest) should still be retried."""
    adapter = _make_adapter()

    attempt = [0]

    async def mock_send_message(**kwargs):
        attempt[0] += 1
        if attempt[0] < 3:
            raise FakeNetworkError("Connection reset")
        return SimpleNamespace(message_id=200)

    adapter._bot = SimpleNamespace(send_message=mock_send_message)

    result = await adapter.send(
        chat_id="123",
        content="test message",
    )

    assert result.success is True
    assert attempt[0] == 3  # Two retries then success


@pytest.mark.asyncio
async def test_send_does_not_retry_timeout():
    """TimedOut (subclass of NetworkError) should NOT be retried in send().

    The request may have already been delivered to the user — retrying
    would send duplicate messages.
    """
    adapter = _make_adapter()

    attempt = [0]

    async def mock_send_message(**kwargs):
        attempt[0] += 1
        raise FakeTimedOut("Timed out waiting for Telegram response")

    adapter._bot = SimpleNamespace(send_message=mock_send_message)

    result = await adapter.send(
        chat_id="123",
        content="test message",
    )

    assert result.success is False
    assert "Timed out" in result.error
    # CRITICAL: only 1 attempt — no retry for TimedOut
    assert attempt[0] == 1


@pytest.mark.asyncio
async def test_thread_fallback_only_fires_once():
    """After clearing thread_id, subsequent chunks should also use None."""
    adapter = _make_adapter()

    call_log = []

    async def mock_send_message(**kwargs):
        call_log.append(dict(kwargs))
        tid = kwargs.get("message_thread_id")
        if tid is not None:
            raise FakeBadRequest("Message thread not found")
        return SimpleNamespace(message_id=42)

    adapter._bot = SimpleNamespace(send_message=mock_send_message)

    # Send a long message that gets split into chunks
    long_msg = "A" * 5000  # Exceeds Telegram's 4096 limit
    result = await adapter.send(
        chat_id="123",
        content=long_msg,
        metadata={"thread_id": "99999"},
    )

    assert result.success is True
    # First chunk: attempt with thread → fail → retry without → succeed
    # Second chunk: should use thread_id=None directly (effective_thread_id
    # was cleared per-chunk but the metadata doesn't change between chunks)
    # The key point: the message was delivered despite the invalid thread


@pytest.mark.asyncio
async def test_send_retries_retry_after_errors():
    """Telegram flood control should back off and retry instead of failing fast."""
    adapter = _make_adapter()

    attempt = [0]

    async def mock_send_message(**kwargs):
        attempt[0] += 1
        if attempt[0] == 1:
            raise FakeRetryAfter(2)
        return SimpleNamespace(message_id=300)

    adapter._bot = SimpleNamespace(send_message=mock_send_message)

    result = await adapter.send(chat_id="123", content="test message")

    assert result.success is True
    assert result.message_id == "300"
    assert attempt[0] == 2