"""Tests for Telegram DM Private Chat Topics (Bot API 9.4).

Covers:
- _setup_dm_topics: loading persisted thread_ids from config
- _setup_dm_topics: creating new topics via API when no thread_id
- _persist_dm_topic_thread_id: saving thread_id back to config.yaml
- _get_dm_topic_info: looking up topic config by thread_id
- _cache_dm_topic_from_message: caching thread_ids from incoming messages
- _build_message_event: DM topic resolution in message events
"""

import asyncio
import os
import sys
from pathlib import Path
from types import SimpleNamespace
from unittest.mock import AsyncMock, MagicMock, patch, mock_open

import pytest

from gateway.config import PlatformConfig


def _ensure_telegram_mock():
    if "telegram" in sys.modules and hasattr(sys.modules["telegram"], "__file__"):
        return

    telegram_mod = MagicMock()
    telegram_mod.ext.ContextTypes.DEFAULT_TYPE = type(None)
    telegram_mod.constants.ParseMode.MARKDOWN_V2 = "MarkdownV2"
    telegram_mod.constants.ChatType.GROUP = "group"
    telegram_mod.constants.ChatType.SUPERGROUP = "supergroup"
    telegram_mod.constants.ChatType.CHANNEL = "channel"
    telegram_mod.constants.ChatType.PRIVATE = "private"

    for name in ("telegram", "telegram.ext", "telegram.constants", "telegram.request"):
        sys.modules.setdefault(name, telegram_mod)


_ensure_telegram_mock()

from gateway.platforms.telegram import TelegramAdapter  # noqa: E402


def _make_adapter(dm_topics_config=None):
    """Create a TelegramAdapter with optional DM topics config."""
    extra = {}
    if dm_topics_config is not None:
        extra["dm_topics"] = dm_topics_config
    config = PlatformConfig(enabled=True, token="***", extra=extra)
    adapter = TelegramAdapter(config)
    return adapter


# ── _setup_dm_topics: load persisted thread_ids ──


@pytest.mark.asyncio
async def test_setup_dm_topics_loads_persisted_thread_ids():
    """Topics with thread_id in config should be loaded into cache, not created."""
    adapter = _make_adapter([
        {
            "chat_id": 111,
            "topics": [
                {"name": "General", "thread_id": 100},
                {"name": "Work", "thread_id": 200},
            ],
        }
    ])
    adapter._bot = AsyncMock()

    await adapter._setup_dm_topics()

    # Both should be in cache
    assert adapter._dm_topics["111:General"] == 100
    assert adapter._dm_topics["111:Work"] == 200
    # create_forum_topic should NOT have been called
    adapter._bot.create_forum_topic.assert_not_called()


@pytest.mark.asyncio
async def test_setup_dm_topics_creates_when_no_thread_id():
    """Topics without thread_id should be created via API."""
    adapter = _make_adapter([
        {
            "chat_id": 222,
            "topics": [
                {"name": "NewTopic", "icon_color": 7322096},
            ],
        }
    ])
    adapter._bot = AsyncMock()
    mock_topic = SimpleNamespace(message_thread_id=999)
    adapter._bot.create_forum_topic.return_value = mock_topic

    # Mock the persist method so it doesn't touch the filesystem
    adapter._persist_dm_topic_thread_id = MagicMock()

    await adapter._setup_dm_topics()

    # Should have been created
    adapter._bot.create_forum_topic.assert_called_once_with(
        chat_id=222, name="NewTopic", icon_color=7322096,
    )
    # Should be in cache
    assert adapter._dm_topics["222:NewTopic"] == 999
    # Should persist
    adapter._persist_dm_topic_thread_id.assert_called_once_with(222, "NewTopic", 999)


@pytest.mark.asyncio
async def test_setup_dm_topics_mixed_persisted_and_new():
    """Mix of persisted and new topics should work correctly."""
    adapter = _make_adapter([
        {
            "chat_id": 333,
            "topics": [
                {"name": "Existing", "thread_id": 50},
                {"name": "New", "icon_color": 123},
            ],
        }
    ])
    adapter._bot = AsyncMock()
    mock_topic = SimpleNamespace(message_thread_id=777)
    adapter._bot.create_forum_topic.return_value = mock_topic
    adapter._persist_dm_topic_thread_id = MagicMock()

    await adapter._setup_dm_topics()

    # Existing loaded from config
    assert adapter._dm_topics["333:Existing"] == 50
    # New created via API
    assert adapter._dm_topics["333:New"] == 777
    # Only one API call (for "New")
    adapter._bot.create_forum_topic.assert_called_once()


@pytest.mark.asyncio
async def test_setup_dm_topics_skips_empty_config():
    """Empty dm_topics config should be a no-op."""
    adapter = _make_adapter([])
    adapter._bot = AsyncMock()

    await adapter._setup_dm_topics()

    adapter._bot.create_forum_topic.assert_not_called()
    assert adapter._dm_topics == {}


@pytest.mark.asyncio
async def test_setup_dm_topics_no_config():
    """No dm_topics in config at all should be a no-op."""
    adapter = _make_adapter()
    adapter._bot = AsyncMock()

    await adapter._setup_dm_topics()

    adapter._bot.create_forum_topic.assert_not_called()


# ── _create_dm_topic: error handling ──


@pytest.mark.asyncio
async def test_create_dm_topic_handles_duplicate_error():
    """Duplicate topic error should return None gracefully."""
    adapter = _make_adapter()
    adapter._bot = AsyncMock()
    adapter._bot.create_forum_topic.side_effect = Exception("topic_name_duplicate")

    result = await adapter._create_dm_topic(chat_id=111, name="General")

    assert result is None


@pytest.mark.asyncio
async def test_create_dm_topic_handles_generic_error():
    """Generic error should return None with warning."""
    adapter = _make_adapter()
    adapter._bot = AsyncMock()
    adapter._bot.create_forum_topic.side_effect = Exception("some random error")

    result = await adapter._create_dm_topic(chat_id=111, name="General")

    assert result is None


@pytest.mark.asyncio
async def test_create_dm_topic_returns_none_without_bot():
    """No bot instance should return None."""
    adapter = _make_adapter()
    adapter._bot = None

    result = await adapter._create_dm_topic(chat_id=111, name="General")

    assert result is None


# ── _persist_dm_topic_thread_id ──


def test_persist_dm_topic_thread_id_writes_config(tmp_path):
    """Should write thread_id into the correct topic in config.yaml."""
    import yaml

    config_data = {
        "platforms": {
            "telegram": {
                "extra": {
                    "dm_topics": [
                        {
                            "chat_id": 111,
                            "topics": [
                                {"name": "General", "icon_color": 123},
                                {"name": "Work", "icon_color": 456},
                            ],
                        }
                    ]
                }
            }
        }
    }

    config_file = tmp_path / ".hermes" / "config.yaml"
    config_file.parent.mkdir(parents=True)
    with open(config_file, "w") as f:
        yaml.dump(config_data, f)

    adapter = _make_adapter()

    with patch.object(Path, "home", return_value=tmp_path), \
         patch.dict(os.environ, {"HERMES_HOME": str(tmp_path / ".hermes")}):
        adapter._persist_dm_topic_thread_id(111, "General", 999)

    with open(config_file) as f:
        result = yaml.safe_load(f)

    topics = result["platforms"]["telegram"]["extra"]["dm_topics"][0]["topics"]
    assert topics[0]["thread_id"] == 999
    assert "thread_id" not in topics[1]  # "Work" should be untouched


def test_persist_dm_topic_thread_id_skips_if_already_set(tmp_path):
    """Should not overwrite an existing thread_id."""
    import yaml

    config_data = {
        "platforms": {
            "telegram": {
                "extra": {
                    "dm_topics": [
                        {
                            "chat_id": 111,
                            "topics": [
                                {"name": "General", "icon_color": 123, "thread_id": 500},
                            ],
                        }
                    ]
                }
            }
        }
    }

    config_file = tmp_path / ".hermes" / "config.yaml"
    config_file.parent.mkdir(parents=True)
    with open(config_file, "w") as f:
        yaml.dump(config_data, f)

    adapter = _make_adapter()

    with patch.object(Path, "home", return_value=tmp_path):
        adapter._persist_dm_topic_thread_id(111, "General", 999)

    with open(config_file) as f:
        result = yaml.safe_load(f)

    topics = result["platforms"]["telegram"]["extra"]["dm_topics"][0]["topics"]
    assert topics[0]["thread_id"] == 500  # unchanged


# ── _get_dm_topic_info ──


def test_get_dm_topic_info_finds_cached_topic():
    """Should return topic config when thread_id is in cache."""
    adapter = _make_adapter([
        {
            "chat_id": 111,
            "topics": [
                {"name": "General", "skill": "my-skill"},
            ],
        }
    ])
    adapter._dm_topics["111:General"] = 100

    result = adapter._get_dm_topic_info("111", "100")

    assert result is not None
    assert result["name"] == "General"
    assert result["skill"] == "my-skill"


def test_get_dm_topic_info_returns_none_for_unknown():
    """Should return None for unknown thread_id."""
    adapter = _make_adapter([
        {
            "chat_id": 111,
            "topics": [{"name": "General"}],
        }
    ])
    # Mock reload to avoid filesystem access
    adapter._reload_dm_topics_from_config = lambda: None

    result = adapter._get_dm_topic_info("111", "999")

    assert result is None


def test_get_dm_topic_info_returns_none_without_config():
    """Should return None if no dm_topics config."""
    adapter = _make_adapter()
    adapter._reload_dm_topics_from_config = lambda: None

    result = adapter._get_dm_topic_info("111", "100")

    assert result is None


def test_get_dm_topic_info_returns_none_for_none_thread():
    """Should return None if thread_id is None."""
    adapter = _make_adapter([
        {"chat_id": 111, "topics": [{"name": "General"}]}
    ])

    result = adapter._get_dm_topic_info("111", None)

    assert result is None


def test_get_dm_topic_info_hot_reloads_from_config(tmp_path):
    """Should find a topic added to config after startup (hot-reload)."""
    import yaml

    # Start with empty topics
    adapter = _make_adapter([
        {"chat_id": 111, "topics": []}
    ])

    # Write config with a new topic + thread_id
    config_data = {
        "platforms": {
            "telegram": {
                "extra": {
                    "dm_topics": [
                        {
                            "chat_id": 111,
                            "topics": [
                                {"name": "NewProject", "thread_id": 555},
                            ],
                        }
                    ]
                }
            }
        }
    }
    config_file = tmp_path / ".hermes" / "config.yaml"
    config_file.parent.mkdir(parents=True)
    with open(config_file, "w") as f:
        yaml.dump(config_data, f)

    with patch.object(Path, "home", return_value=tmp_path), \
         patch.dict(os.environ, {"HERMES_HOME": str(tmp_path / ".hermes")}):
        result = adapter._get_dm_topic_info("111", "555")

    assert result is not None
    assert result["name"] == "NewProject"
    # Should now be cached
    assert adapter._dm_topics["111:NewProject"] == 555


# ── _cache_dm_topic_from_message ──


def test_cache_dm_topic_from_message():
    """Should cache a new topic mapping."""
    adapter = _make_adapter()

    adapter._cache_dm_topic_from_message("111", "100", "General")

    assert adapter._dm_topics["111:General"] == 100


def test_cache_dm_topic_from_message_no_overwrite():
    """Should not overwrite an existing cached topic."""
    adapter = _make_adapter()
    adapter._dm_topics["111:General"] = 100

    adapter._cache_dm_topic_from_message("111", "999", "General")

    assert adapter._dm_topics["111:General"] == 100  # unchanged


# ── _build_message_event: auto_skill binding ──


def _make_mock_message(chat_id=111, chat_type="private", text="hello", thread_id=None,
                       user_id=42, user_name="Test User", forum_topic_created=None):
    """Create a mock Telegram Message for _build_message_event tests."""
    chat = SimpleNamespace(
        id=chat_id,
        type=chat_type,
        title=None,
    )
    # Add full_name attribute for DM chats
    if not hasattr(chat, "full_name"):
        chat.full_name = user_name

    user = SimpleNamespace(
        id=user_id,
        full_name=user_name,
    )

    msg = SimpleNamespace(
        chat=chat,
        from_user=user,
        text=text,
        message_thread_id=thread_id,
        message_id=1001,
        reply_to_message=None,
        date=None,
        forum_topic_created=forum_topic_created,
    )
    return msg


def test_build_message_event_sets_auto_skill():
    """When topic has a skill binding, auto_skill should be set on the event."""
    from gateway.platforms.base import MessageType

    adapter = _make_adapter([
        {
            "chat_id": 111,
            "topics": [
                {"name": "My Project", "skill": "accessibility-auditor", "thread_id": 100},
            ],
        }
    ])
    adapter._dm_topics["111:My Project"] = 100

    msg = _make_mock_message(chat_id=111, thread_id=100, text="check this page")
    event = adapter._build_message_event(msg, MessageType.TEXT)

    assert event.auto_skill == "accessibility-auditor"
    # chat_topic should be the clean topic name, no [skill: ...] suffix
    assert event.source.chat_topic == "My Project"


def test_build_message_event_no_auto_skill_without_binding():
    """Topics without skill binding should have auto_skill=None."""
    from gateway.platforms.base import MessageType

    adapter = _make_adapter([
        {
            "chat_id": 111,
            "topics": [
                {"name": "General", "thread_id": 200},
            ],
        }
    ])
    adapter._dm_topics["111:General"] = 200

    msg = _make_mock_message(chat_id=111, thread_id=200)
    event = adapter._build_message_event(msg, MessageType.TEXT)

    assert event.auto_skill is None
    assert event.source.chat_topic == "General"


def test_build_message_event_no_auto_skill_without_thread():
    """Regular DM messages (no thread_id) should have auto_skill=None."""
    from gateway.platforms.base import MessageType

    adapter = _make_adapter()
    msg = _make_mock_message(chat_id=111, thread_id=None)
    event = adapter._build_message_event(msg, MessageType.TEXT)

    assert event.auto_skill is None