"""«👥 Участники» for admins: list, invite by QR, revoke access (SPEC A-1, A-7)."""

from datetime import datetime
from enum import StrEnum

from aiogram import Bot, F, Router
from aiogram.filters.callback_data import CallbackData
from aiogram.fsm.context import FSMContext
from aiogram.types import BufferedInputFile, CallbackQuery, InlineKeyboardMarkup, Message
from aiogram.utils.keyboard import InlineKeyboardBuilder

from app.access.qr import invite_link, qr_png
from app.access.service import AccessService
from app.bot.menu import Nav, NavAction
from app.db.models import Role, User
from app.texts import Texts


class MembersAction(StrEnum):
    INVITE = "inv"
    ASK_REVOKE = "ask"
    REVOKE = "rev"
    LIST = "list"


class MembersCb(CallbackData, prefix="mem"):
    action: MembersAction
    tg_id: int = 0


def _fmt(dt: datetime | None, never: str) -> str:
    return dt.strftime("%d.%m %H:%M") if dt else never


def render_members(texts: Texts, members: list[User]) -> tuple[str, InlineKeyboardMarkup]:
    t = texts.members
    lines = [t.title.format(count=len(members)), ""]
    for m in members:
        lines.append(
            t.line.format(
                icon="👑" if m.role is Role.ADMIN else "👤",
                name=m.full_name,
                username=f" @{m.username}" if m.username else "",
                joined=_fmt(m.joined_at, t.never),
                seen=_fmt(m.last_seen_at, t.never),
            )
        )
    kb = InlineKeyboardBuilder()
    kb.button(text=t.invite, callback_data=MembersCb(action=MembersAction.INVITE))
    for m in members:
        if m.role is not Role.ADMIN:
            kb.button(
                text=t.revoke.format(name=m.full_name),
                callback_data=MembersCb(action=MembersAction.ASK_REVOKE, tg_id=m.tg_id),
            )
    kb.button(text=texts.menu.back, callback_data=Nav(action=NavAction.BACK))
    kb.adjust(1)
    return "\n".join(lines), kb.as_markup()


def build_router(texts: Texts, access: AccessService) -> Router:
    router = Router(name="members")
    t = texts.members
    # Every handler here is admin-only; a member who somehow has the button (e.g. was demoted) gets nothing.

    def is_admin(member: User | None) -> bool:
        return member is not None and member.role is Role.ADMIN

    @router.message(F.text == texts.menu.members)
    async def open_members(message: Message, state: FSMContext, member: User) -> None:
        if not is_admin(member):
            return
        await state.clear()
        text, kb = render_members(texts, await access.list_members())
        await message.answer(text, reply_markup=kb)

    @router.callback_query(MembersCb.filter())
    async def on_action(query: CallbackQuery, callback_data: MembersCb, bot: Bot, member: User) -> None:
        if not is_admin(member) or not isinstance(query.message, Message):
            await query.answer()
            return
        msg = query.message
        match callback_data.action:
            case MembersAction.INVITE:
                invite = await access.create_invite(member.tg_id)
                me = await bot.me()
                link = invite_link(me.username or "", invite.token)
                caption = t.invite_caption.format(link=link, expires=invite.expires_at.strftime("%d.%m %H:%M"))
                await msg.answer_photo(BufferedInputFile(qr_png(link), "invite.png"), caption=caption)
            case MembersAction.ASK_REVOKE:
                target = await access.get_member(callback_data.tg_id)
                name = target.full_name if target else str(callback_data.tg_id)
                kb = InlineKeyboardBuilder()
                kb.button(
                    text=t.confirm_yes, callback_data=MembersCb(action=MembersAction.REVOKE, tg_id=callback_data.tg_id)
                )
                kb.button(text=t.confirm_no, callback_data=MembersCb(action=MembersAction.LIST))
                await msg.edit_text(t.confirm.format(name=name), reply_markup=kb.as_markup())
            case MembersAction.REVOKE:
                target = await access.get_member(callback_data.tg_id)
                name = target.full_name if target else str(callback_data.tg_id)
                ok = await access.revoke(callback_data.tg_id)
                text, kb_markup = render_members(texts, await access.list_members())
                note = t.revoked.format(name=name) if ok else t.not_revoked
                await msg.edit_text(f"{note}\n\n{text}", reply_markup=kb_markup)
            case MembersAction.LIST:
                text, kb_markup = render_members(texts, await access.list_members())
                await msg.edit_text(text, reply_markup=kb_markup)
        await query.answer()

    return router