"""Поддержка: личный чат пользователя ↔ персональный топик в группе операторов.

Пользователь нажимает «🆘 Поддержка» в режиме «Помощь». Дальше все его сообщения
копируются в его персональный топик группы; любое сообщение оператора в этом
топике копируется обратно пользователю. Сообщение, начинающееся с
``SUPPORT_NOTE_PREFIX`` (по умолчанию ``//``), остаётся заметкой внутри топика.
"""

from __future__ import annotations

import asyncio
import html
import logging
import os
from contextlib import closing
from typing import Any, Awaitable, Callable

from aiogram import BaseMiddleware, Bot, F, Router
from aiogram.types import Message, TelegramObject, User

from keyboards import MAIN_MENU_VALUE, SUPPORT_BUTTON, SUPPORT_VALUE, TRAINING_RESET_VALUE, resolve_button_text
from user_store import connect

logger = logging.getLogger(__name__)

router = Router(name="support")

NOTE_PREFIX_DEFAULT = "//"
TOPIC_TITLE_LIMIT = 128

SUPPORT_START_TEXT = (
    "🆘 <b>Поддержка</b>\n\n"
    "Что случилось? Опиши проблему прямо здесь — я передам сообщение оператору, "
    "он ответит в этом чате.\n\n"
    "Можно писать текстом, присылать фото, документы и голосовые. "
    "Кнопка «Главное меню» завершает обращение: бот снова работает как обычно, "
    "а при следующем нажатии «Поддержка» переписка продолжится в том же топике."
)
SUPPORT_UNAVAILABLE_TEXT = (
    "🆘 Поддержка временно недоступна. Попробуй позже или вернись в главное меню."
)
SUPPORT_RELAY_FAILED_TEXT = (
    "⚠️ Не удалось передать сообщение оператору. Попробуй отправить его ещё раз."
)


# --------------------------------------------------------------------------- #
# Конфигурация
# --------------------------------------------------------------------------- #

def support_group_id() -> int | None:
    raw = os.getenv("SUPPORT_GROUP_ID", "").strip()
    if not raw:
        return None
    try:
        return int(raw)
    except ValueError:
        logger.warning("SUPPORT_GROUP_ID is not an integer; support disabled")
        return None


def note_prefix() -> str:
    raw = os.getenv("SUPPORT_NOTE_PREFIX", "").strip()
    return raw or NOTE_PREFIX_DEFAULT


def topic_icon_emoji_id() -> str | None:
    raw = os.getenv("SUPPORT_TOPIC_EMOJI_ID", "").strip()
    return raw or None


def is_enabled() -> bool:
    return support_group_id() is not None


def _is_support_chat(chat: Any) -> bool:
    group_id = support_group_id()
    return group_id is not None and int(chat.id) == group_id


# --------------------------------------------------------------------------- #
# Хранилище: user_id ↔ message_thread_id
# --------------------------------------------------------------------------- #

def init_support_table(db_path: str | None = None) -> None:
    with closing(connect(db_path)) as connection, connection:
        connection.execute(
            """
            CREATE TABLE IF NOT EXISTS support_topics (
                telegram_user_id INTEGER PRIMARY KEY,
                thread_id INTEGER NOT NULL,
                is_active INTEGER NOT NULL DEFAULT 1,
                created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
                updated_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
            )
            """
        )


def get_topic(user_id: int, db_path: str | None = None) -> int | None:
    with closing(connect(db_path)) as connection:
        row = connection.execute(
            "SELECT thread_id FROM support_topics WHERE telegram_user_id = ?",
            (int(user_id),),
        ).fetchone()
    return int(row["thread_id"]) if row else None


def set_topic(user_id: int, thread_id: int, db_path: str | None = None) -> None:
    with closing(connect(db_path)) as connection, connection:
        connection.execute(
            """
            INSERT INTO support_topics (telegram_user_id, thread_id, is_active, updated_at)
            VALUES (?, ?, 1, CURRENT_TIMESTAMP)
            ON CONFLICT(telegram_user_id) DO UPDATE SET
                thread_id = excluded.thread_id,
                is_active = 1,
                updated_at = CURRENT_TIMESTAMP
            """,
            (int(user_id), int(thread_id)),
        )


def forget_topic(user_id: int, db_path: str | None = None) -> None:
    with closing(connect(db_path)) as connection, connection:
        connection.execute(
            "DELETE FROM support_topics WHERE telegram_user_id = ?",
            (int(user_id),),
        )


def set_active(user_id: int, active: bool, db_path: str | None = None) -> None:
    with closing(connect(db_path)) as connection, connection:
        connection.execute(
            """
            UPDATE support_topics
            SET is_active = ?, updated_at = CURRENT_TIMESTAMP
            WHERE telegram_user_id = ?
            """,
            (1 if active else 0, int(user_id)),
        )


def is_support_active(user_id: int, db_path: str | None = None) -> bool:
    if not is_enabled():
        return False
    with closing(connect(db_path)) as connection:
        row = connection.execute(
            "SELECT is_active FROM support_topics WHERE telegram_user_id = ?",
            (int(user_id),),
        ).fetchone()
    return bool(row and row["is_active"])


def get_user_by_thread(thread_id: int, db_path: str | None = None) -> int | None:
    with closing(connect(db_path)) as connection:
        row = connection.execute(
            "SELECT telegram_user_id FROM support_topics WHERE thread_id = ?",
            (int(thread_id),),
        ).fetchone()
    return int(row["telegram_user_id"]) if row else None


# --------------------------------------------------------------------------- #
# Топик и карточка пользователя
# --------------------------------------------------------------------------- #

def topic_title(user: User) -> str:
    full_name = " ".join(
        part for part in (user.first_name, user.last_name) if part
    ).strip() or "Пользователь"
    if user.username:
        title = f"{full_name} · @{user.username}"
    else:
        title = f"{full_name} · {user.id}"
    return title[:TOPIC_TITLE_LIMIT]


def profile_card(user: User) -> str:
    full_name = " ".join(
        part for part in (user.first_name, user.last_name) if part
    ).strip() or "Пользователь"
    lines = [
        "🆘 <b>Новое обращение</b>",
        f"<b>Имя:</b> {html.escape(full_name)}",
    ]
    if user.username:
        lines.append(f"<b>Username:</b> @{html.escape(user.username)}")
    lines.append(f"<b>ID:</b> <code>{user.id}</code>")
    lines.append("")
    lines.append("Ответь в этом топике — сообщение придёт пользователю в личку.")
    lines.append(f"Ответ с префиксом <code>{html.escape(note_prefix())}</code> останется здесь.")
    return "\n".join(lines)


async def send_profile_card(bot: Bot, user: User, thread_id: int) -> None:
    group_id = support_group_id()
    if group_id is None:
        return
    card = profile_card(user)
    photo_file_id = None
    try:
        photos = await bot.get_user_profile_photos(user_id=user.id, limit=1)
        if photos.total_count and photos.photos and photos.photos[0]:
            photo_file_id = photos.photos[0][-1].file_id
    except Exception as exc:
        logger.info("Support profile photo unavailable (%s)", type(exc).__name__)
    try:
        if photo_file_id:
            await bot.send_photo(
                chat_id=group_id,
                photo=photo_file_id,
                caption=card,
                message_thread_id=thread_id,
                parse_mode="HTML",
            )
        else:
            await bot.send_message(
                chat_id=group_id,
                text=card,
                message_thread_id=thread_id,
                parse_mode="HTML",
            )
    except Exception as exc:
        logger.warning("Support profile card send failed (%s)", type(exc).__name__)


async def ensure_topic(bot: Bot, user: User) -> int | None:
    """Возвращает thread_id персонального топика, создавая его при необходимости."""
    group_id = support_group_id()
    if group_id is None:
        return None
    existing = await asyncio.to_thread(get_topic, user.id)
    if existing is not None:
        return existing
    emoji_id = topic_icon_emoji_id()
    try:
        kwargs: dict[str, Any] = {"chat_id": group_id, "name": topic_title(user)}
        if emoji_id:
            kwargs["icon_custom_emoji_id"] = emoji_id
        topic = await bot.create_forum_topic(**kwargs)
    except Exception as exc:
        logger.error("Support topic creation failed (%s)", type(exc).__name__)
        return None
    thread_id = int(topic.message_thread_id)
    await asyncio.to_thread(set_topic, user.id, thread_id)
    await send_profile_card(bot, user, thread_id)
    return thread_id


async def deactivate(user_id: int) -> None:
    await asyncio.to_thread(set_active, user_id, False)


# --------------------------------------------------------------------------- #
# Пользователь → топик
# --------------------------------------------------------------------------- #

async def relay_user_message(message: Message) -> bool:
    """Копирует сообщение пользователя в его топик. True — сообщение ушло."""
    bot = message.bot
    user = message.from_user
    group_id = support_group_id()
    if group_id is None or bot is None or user is None:
        return False
    thread_id = await ensure_topic(bot, user)
    if thread_id is None:
        try:
            await message.answer(SUPPORT_UNAVAILABLE_TEXT)
        except Exception:
            logger.debug("Support unavailable notice failed")
        return False
    try:
        await bot.copy_message(
            chat_id=group_id,
            from_chat_id=message.chat.id,
            message_id=message.message_id,
            message_thread_id=thread_id,
        )
        return True
    except Exception as exc:
        if _is_missing_thread(exc):
            logger.warning("Support topic %s is gone; recreating", thread_id)
            await asyncio.to_thread(forget_topic, user.id)
            return await relay_user_message(message)
        logger.error("Support relay to topic failed (%s)", type(exc).__name__)
        try:
            await message.answer(SUPPORT_RELAY_FAILED_TEXT)
        except Exception:
            logger.debug("Support relay failure notice failed")
        return False


def _is_missing_thread(exc: Exception) -> bool:
    detail = str(exc).lower()
    return "thread not found" in detail or "message thread not found" in detail


async def start_support(message: Message) -> None:
    """Открывает обращение: создаёт топик и объясняет пользователю формат."""
    bot = message.bot
    user = message.from_user
    if bot is None or user is None:
        return
    if not is_enabled():
        await message.answer(SUPPORT_UNAVAILABLE_TEXT)
        return
    thread_id = await ensure_topic(bot, user)
    if thread_id is None:
        await message.answer(SUPPORT_UNAVAILABLE_TEXT)
        return
    await asyncio.to_thread(set_active, user.id, True)
    await message.answer(SUPPORT_START_TEXT, parse_mode="HTML")


# --------------------------------------------------------------------------- #
# Топик → пользователь
# --------------------------------------------------------------------------- #

def _is_service_message(message: Message) -> bool:
    text = (message.text or message.caption or "").strip()
    prefix = note_prefix()
    return bool(prefix) and text.startswith(prefix)


@router.message(F.chat.func(_is_support_chat), F.is_topic_message.as_("topic"))
async def handle_support_group_message(message: Message) -> None:
    """Все сообщения из топиков группы поддержки, кроме служебных, уходят пользователю."""
    group_id = support_group_id()
    thread_id = message.message_thread_id
    if group_id is None or thread_id is None:
        return
    sender = message.from_user
    if sender is None or sender.is_bot:
        return
    if _is_service_message(message):
        return
    user_id = await asyncio.to_thread(get_user_by_thread, thread_id)
    if user_id is None:
        logger.info("Support topic %s has no known user", thread_id)
        return
    bot = message.bot
    if bot is None:
        return
    try:
        await bot.copy_message(
            chat_id=user_id,
            from_chat_id=message.chat.id,
            message_id=message.message_id,
        )
    except Exception as exc:
        logger.error("Support reply delivery failed user=%s (%s)", user_id, type(exc).__name__)
        try:
            await message.reply(
                "⚠️ Не удалось доставить сообщение пользователю. "
                "Возможно, он остановил бота."
            )
        except Exception:
            logger.debug("Support delivery notice failed")


# --------------------------------------------------------------------------- #
# Middleware: пользователь → топик
# --------------------------------------------------------------------------- #

def _is_support_button(message: Message) -> bool:
    if not message.text:
        return False
    return resolve_button_text((message.text or "").strip()) == SUPPORT_VALUE


class SupportRelayMiddleware(BaseMiddleware):
    """Копирует входящие_private сообщения активного обращения в топик."""

    async def __call__(
        self,
        handler: Callable[[TelegramObject, dict[str, Any]], Awaitable[Any]],
        event: TelegramObject,
        data: dict[str, Any],
    ) -> Any:
        if not isinstance(event, Message) or not is_enabled():
            return await handler(event, data)
        user = event.from_user
        if user is None or user.is_bot:
            return await handler(event, data)
        if event.chat.type != "private":
            return await handler(event, data)
        if _is_support_chat(event.chat):
            return await handler(event, data)
        if _is_support_button(event) or _is_main_menu_button(event):
            return await handler(event, data)
        try:
            active = await asyncio.to_thread(is_support_active, user.id)
        except Exception as exc:
            logger.warning("Support active lookup failed (%s)", type(exc).__name__)
            return await handler(event, data)
        if not active:
            return await handler(event, data)
        await relay_user_message(event)
        # Сообщение уже доставлено оператору; обычные обработчики не запускаем.
        return None


def _is_main_menu_button(message: Message) -> bool:
    if not message.text:
        return False
    return resolve_button_text((message.text or "").strip()) == MAIN_MENU_VALUE