from math import ceil

from aiogram import Bot, Router
from aiogram.filters import Command
from aiogram.types import InlineKeyboardButton, InlineKeyboardMarkup, Message
from aiogram.types.callback_query import CallbackQuery
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy.sql.functions import count

from libs.msg import eclipse_text
from models import Announcement
from models.callback_data import AnnounceItemClb, AnnouncePageClb

router = Router(name="announcements")
PAGE_SIZE = 5


async def get_reply_markup(
    page: int,
    session: AsyncSession,
) -> InlineKeyboardMarkup | None:
    total = await session.scalar(select(count()).select_from(Announcement))
    assert total is not None
    total_pages = ceil(total / PAGE_SIZE)

    if total == 0:
        return None

    page = max(0, min(page, total_pages - 1))
    query = (
        select(Announcement)
        .offset(PAGE_SIZE * page)
        .limit(PAGE_SIZE)
        .order_by(Announcement.id.desc())
    )
    announcements = await session.scalars(query)

    announcement_buttons = [
        [
            InlineKeyboardButton(
                text=(
                    f"{eclipse_text(a.message.text, 10)} "
                    f"({a.datetime.strftime('%d %b %y г.')})"
                ),
                callback_data=AnnounceItemClb(page=page, announce_id=a.id).pack(),
            )
        ]
        for a in announcements
    ]

    page_buttons = []
    if page > 0:
        page_buttons.append(
            InlineKeyboardButton(
                text="◀️",
                callback_data=AnnouncePageClb(page=page - 1).pack(),
            )
        )
    if page < total_pages - 1:
        page_buttons.append(
            InlineKeyboardButton(
                text="▶️",
                callback_data=AnnouncePageClb(page=page + 1).pack(),
            )
        )

    return InlineKeyboardMarkup(inline_keyboard=[*announcement_buttons, page_buttons])


@router.message(Command("announcements"))
async def command(msg: Message, bot: Bot, session: AsyncSession) -> None:
    reply_markup = await get_reply_markup(0, session)

    if reply_markup is None:
        await msg.answer("Нету анонсов для просмотра.")
        return

    await msg.answer("Выберете анонс для просмотра.", reply_markup=reply_markup)


@router.callback_query(AnnouncePageClb.filter())
async def page(
    clb: CallbackQuery,
    callback_data: AnnouncePageClb,
    session: AsyncSession,
) -> None:
    assert isinstance(clb.message, Message)

    reply_markup = await get_reply_markup(callback_data.page, session)
    await clb.message.edit_text(
        "Выберете анонс для просмотра:",
        reply_markup=reply_markup,
    )

    await clb.answer()


@router.callback_query(AnnounceItemClb.filter())
async def item(
    clb: CallbackQuery,
    callback_data: AnnounceItemClb,
    session: AsyncSession,
) -> None:
    assert isinstance(clb.message, Message)

    announcement = await session.get(Announcement, callback_data.announce_id)
    assert announcement is not None

    rich_text = announcement.message
    reply_markup = InlineKeyboardMarkup(
        inline_keyboard=[
            [
                InlineKeyboardButton(
                    text="Назад к выбору",
                    callback_data=AnnouncePageClb(page=callback_data.page).pack(),
                )
            ]
        ]
    )

    await clb.message.edit_text(
        text=rich_text.text,
        entities=rich_text.entities,
        parse_mode=None,
        reply_markup=reply_markup,
    )

    await clb.answer()