from aiogram import F, Router
from aiogram.filters import Command, CommandStart
from aiogram.types import CallbackQuery, InlineKeyboardButton, InlineKeyboardMarkup, Message

from app.api import ApiError, ShopApi

router = Router()


def _catalog_keyboard(products: list[dict]) -> InlineKeyboardMarkup:
    rows = [
        [InlineKeyboardButton(text=f"{item['title']} — {item['price']} ₽", callback_data=f"prod:{item['id']}")]
        for item in products
    ]
    return InlineKeyboardMarkup(inline_keyboard=rows)


def _product_keyboard(product_id: int) -> InlineKeyboardMarkup:
    return InlineKeyboardMarkup(
        inline_keyboard=[
            [
                InlineKeyboardButton(text="В корзину", callback_data=f"add:{product_id}"),
                InlineKeyboardButton(text="Оформить", callback_data="checkout"),
            ]
        ]
    )


def _cart_text(cart: dict) -> str:
    if not cart["items"]:
        return "Корзина пуста."
    lines = [f"{item['title']} × {item['qty']} = {item['line_total']} ₽" for item in cart["items"]]
    lines.append(f"Итого: {cart['total']} ₽")
    lines.append("Оформление: /checkout")
    return "\n".join(lines)


@router.message(CommandStart())
async def start(message: Message) -> None:
    await message.answer("Магазин. /catalog — товары, /cart — корзина, /checkout — заказ без оплаты.")


@router.message(Command("catalog"))
async def catalog(message: Message, api: ShopApi) -> None:
    products = await api.products()
    if not products:
        await message.answer("Каталог пуст.")
        return
    await message.answer("Каталог", reply_markup=_catalog_keyboard(products))


@router.callback_query(F.data.startswith("prod:"))
async def show_product(query: CallbackQuery, api: ShopApi) -> None:
    product_id = int(query.data.split(":", 1)[1])
    try:
        product = await api.product(product_id)
    except ApiError as exc:
        await query.answer(exc.detail, show_alert=True)
        return
    text = f"{product['title']}\n{product['description']}\n{product['price']} ₽\n{product['category_name']}"
    if query.message is not None:
        await query.message.answer(text, reply_markup=_product_keyboard(product_id))
    await query.answer()


@router.callback_query(F.data.startswith("add:"))
async def add_product(query: CallbackQuery, api: ShopApi) -> None:
    if query.from_user is None:
        await query.answer()
        return
    product_id = int(query.data.split(":", 1)[1])
    try:
        cart = await api.add(query.from_user.id, product_id)
    except ApiError as exc:
        await query.answer(exc.detail, show_alert=True)
        return
    await query.answer("Добавлено")
    if query.message is not None:
        await query.message.answer(_cart_text(cart))


@router.message(Command("cart"))
async def cart(message: Message, api: ShopApi) -> None:
    if message.from_user is None:
        return
    data = await api.cart(message.from_user.id)
    await message.answer(_cart_text(data))


@router.message(Command("checkout"))
@router.callback_query(F.data == "checkout")
async def checkout_start(event: Message | CallbackQuery, api: ShopApi) -> None:
    user = event.from_user
    if user is None:
        return
    await api.save_dialog(user.id, "name", None)
    text = "Как вас зовут?"
    if isinstance(event, CallbackQuery):
        await event.answer()
        if event.message is not None:
            await event.message.answer(text)
        return
    await event.answer(text)


@router.message(F.text)
async def dialog(message: Message, api: ShopApi) -> None:
    if message.from_user is None or message.text is None or message.text.startswith("/"):
        return
    state = await api.dialog(message.from_user.id)
    if state is None:
        return
    if state["step"] == "name":
        await api.save_dialog(message.from_user.id, "phone", message.text.strip()[:120])
        await message.answer("Телефон? Можно цифры, пробелы и +()-.")
        return
    if state["step"] != "phone" or not state.get("name"):
        await api.clear_dialog(message.from_user.id)
        return
    try:
        order = await api.order(message.from_user.id, state["name"], message.text.strip())
    except ApiError as exc:
        await message.answer(exc.detail)
        return
    await api.clear_dialog(message.from_user.id)
    await message.answer(
        f"Заказ {order['id']} создан, без оплаты.\nСумма: {order['total']} ₽\nИмя: {order['customer_name']}"
    )