Cart rendering, bug fixes with cart adding/rming

config.py

@@ -16,4 +16,4 @@ POSTGRES_URL = os.getenv(
 
 ### Constants ###
 
-PAGE_SIZE = 6
+PAGE_SIZE = 4

db/models/orders.py

@@ -4,6 +4,7 @@ from sqlalchemy import ForeignKey, BigInteger
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 from sqlalchemy.dialects.postgresql import ENUM
 from db.base import Base
+from db.models.products import Product
 
 
 class OrderStatus(enum.Enum):
@@ -33,3 +34,4 @@ class OrderItem(Base):
     quantity: Mapped[int] = mapped_column(default=1)
 
     order: Mapped["Order"] = relationship("Order", back_populates="items")
+    product: Mapped["Product"] = relationship("Product")

db/models/products.py

@@ -2,6 +2,7 @@ from typing import Optional
 from sqlalchemy import ForeignKey, Text, Index
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 from sqlalchemy.dialects.postgresql import TSVECTOR
+
 from db.base import Base
 
 

dto/__init__.py

@@ -0,0 +1,3 @@
+from .cart import CartItemDTO
+
+__all__ = ["CartItemDTO"]

dto/cart.py

@@ -0,0 +1,19 @@
+from dataclasses import dataclass
+
+
+@dataclass(frozen=True)
+class CartItemDTO:
+    product_id: int
+    name: str
+    quantity: int
+    price: int
+
+    @property
+    def total(self):
+        return self.price * self.quantity
+
+
+@dataclass
+class CartDTO:
+    items: list[CartItemDTO]
+    total: int

handlers/client.py

@@ -10,6 +10,7 @@ from config import PAGE_SIZE
 from misc.kb import main_menu_kb, render_category
 from misc.kb.client import (
     get_back_to_catalogue,
+    render_cart,
     render_product_interactions,
     render_products,
 )
@@ -265,6 +266,9 @@ async def add_to_cart(
     else:
         show_cart = False
         quantity = 0
+        await order_service.clear_cart_item(
+            session, customer=cb.from_user.id, product_id=product_id
+        )
 
     try:
         await cb.message.edit_reply_markup(
@@ -275,6 +279,69 @@ async def add_to_cart(
                 cart_amount=quantity,
             )
         )
-    except Exception:
-        await cb.answer("🍃 Корзина уже пуста.")
-        return
+    except Exception as e:
+        await cb.answer("🍃")
+        raise e
+
+
+@router.callback_query(F.data == "cart")
+async def cart_init(
+    cb: CallbackQuery,
+    state: FSMContext,
+    session: AsyncSession,
+    order_service: OrderService,
+):
+    await state.clear()
+
+    cart = await order_service.build_cart_dto(session, customer=cb.from_user.id)
+
+    await cb.message.edit_text(
+        f"total: {cart.total}₽",
+        reply_markup=render_cart(
+            cart.items[:PAGE_SIZE], show_next=len(cart.items) > PAGE_SIZE
+        ),
+    )
+
+
+@router.message(Command("cart"))
+async def cart_cmd(
+    msg: Message,
+    state: FSMContext,
+    session: AsyncSession,
+    order_service: OrderService,
+):
+    await state.clear()
+
+    cart = await order_service.build_cart_dto(session, customer=msg.from_user.id)
+
+    await msg.answer(
+        f"total: {cart.total}₽",
+        reply_markup=render_cart(
+            cart.items[:PAGE_SIZE], show_next=len(cart.items) > PAGE_SIZE
+        ),
+    )
+
+
+@router.callback_query(F.data.startswith("cart:"))
+async def cart_pagination(
+    cb: CallbackQuery,
+    state: FSMContext,
+    session: AsyncSession,
+    order_service: OrderService,
+):
+    await state.clear()
+
+    page = int(cb.data.split(":")[1])
+
+    cart = await order_service.build_cart_dto(
+        session, customer=cb.from_user.id, offset=page * PAGE_SIZE
+    )
+
+    await cb.message.edit_reply_markup(
+        reply_markup=render_cart(
+            cart.items[:PAGE_SIZE],
+            page=page,
+            show_next=len(cart.items) > PAGE_SIZE,
+            show_prev=page > 0,
+        ),
+    )

misc/kb/client.py

@@ -3,14 +3,31 @@ from typing import Optional
 from aiogram.types import InlineKeyboardButton, InlineKeyboardMarkup
 from aiogram.utils.keyboard import InlineKeyboardBuilder
 
-from db.models import Category
-from db.models.products import Product
+from db.models import Category, Product
+from dto.cart import CartItemDTO
+
+
+def pagination_row(
+    *,
+    page: int,
+    prev_cb: Optional[str] = None,
+    next_cb: Optional[str] = None,
+) -> list[InlineKeyboardButton]:
+    row = []
+
+    if prev_cb:
+        row.append(InlineKeyboardButton(text="⬅️", callback_data=prev_cb))
+
+    row.append(InlineKeyboardButton(text=str(page + 1), callback_data="..."))
+
+    if next_cb:
+        row.append(InlineKeyboardButton(text="➡️", callback_data=next_cb))
+
+    return row
 
 
 def cart_btn(cart_items: int) -> InlineKeyboardButton:
-    return InlineKeyboardButton(
-        text=f"🛒 Корзина ({cart_items})", callback_data="cart"
-    )
+    return InlineKeyboardButton(text=f"🛒 Корзина ({cart_items})", callback_data="cart")
 
 
 def get_back_to_catalogue(
@@ -75,22 +92,10 @@ def render_products(
         for product in products
     ]
 
-    nav = []
-
-    if show_prev:
-        nav.append(
-            InlineKeyboardButton(
-                text="⬅️", callback_data=f"products:{cat_id}:{page - 1}"
-            )
-        )
-
-    nav.append(InlineKeyboardButton(text=str(page), callback_data="..."))
-
-    if show_next:
-        nav.append(
-            InlineKeyboardButton(
-                text="➡️", callback_data=f"products:{cat_id}:{page + 1}"
-            )
+    nav = pagination_row(
+        page=page,
+        prev_cb=f"products:{cat_id}:{page - 1}" if show_prev else None,
+        next_cb=f"products:{cat_id}:{page + 1}" if show_next else None,
     )
 
     return InlineKeyboardBuilder(
@@ -145,3 +150,38 @@ def render_product_interactions(
     btns.append([InlineKeyboardButton(text="⬅️", callback_data=f"cat:{category_id}")])
 
     return InlineKeyboardBuilder(btns).as_markup()
+
+
+def render_cart(
+    cart_items: list[CartItemDTO],
+    *,
+    page: int = 0,
+    show_prev: Optional[bool] = False,
+    show_next: Optional[bool] = False,
+) -> InlineKeyboardMarkup:
+    btns = [
+        InlineKeyboardButton(
+            text=f"{cart_item.quantity} | {cart_item.name} | {cart_item.total}₽",
+            callback_data=f"product:{cart_item.product_id}",
+        )
+        for cart_item in cart_items
+    ]
+
+    nav = pagination_row(
+        page=page,
+        prev_cb=f"cart:{page - 1}" if show_prev else None,
+        next_cb=f"cart:{page + 1}" if show_next else None,
+    )
+
+    return InlineKeyboardBuilder(
+        [
+            [
+                InlineKeyboardButton(
+                    text="⬅️ Назад",
+                    callback_data="menu:main",
+                )
+            ]
+        ]
+        + [btns[i : i + 2] for i in range(0, len(cart_items), 2)]
+        + [nav]
+    ).as_markup()

pyproject.toml

@@ -6,3 +6,6 @@ skip-string-normalization = false
 skip-magic-trailing-comma = false
 
 preview = false
+
+[tool.ruff.lint]
+ignore=["F405", "F403"]

repositories/order_items.py

@@ -1,8 +1,8 @@
 from sqlalchemy.ext.asyncio import AsyncSession
-from sqlalchemy import select, update
+from sqlalchemy import delete, func, select, update
 from typing import Optional
 
-from db.models.orders import Order, OrderItem
+from db.models.orders import OrderItem
 
 
 class OrderItemRepository:
@@ -13,13 +13,22 @@ class OrderItemRepository:
         return await session.scalar(stmt)
 
     async def get_items_by_order(
-        self, session: AsyncSession, order_id: int
+        self, session: AsyncSession, *, order_id: int, limit: int, offset: int = 0
     ) -> list[OrderItem]:
-        stmt = select(OrderItem).where(OrderItem.order_id == order_id)
+        stmt = (
+            select(OrderItem)
+            .where(OrderItem.order_id == order_id)
+            .limit(limit)
+            .offset(offset)
+        )
         result = await session.scalars(stmt)
 
         return list(result)
 
+    async def get_items_count(self, session: AsyncSession, *, order_id: int) -> int:
+        stmt = select(func.count(OrderItem.id)).where(OrderItem.order_id == order_id)
+        return await session.scalar(stmt) or 0
+
     async def get_item_by_order_and_product(
         self, session: AsyncSession, *, order_id: int, product_id: int
     ) -> Optional[OrderItem]:
@@ -58,3 +67,9 @@ class OrderItemRepository:
         await session.commit()
 
         return order_item
+
+    async def delete_item(self, session: AsyncSession, item_id: int):
+        stmt = delete(OrderItem.__table__).where(OrderItem.id == item_id)
+
+        await session.execute(stmt)
+        await session.commit()

repositories/orders.py

@@ -2,7 +2,9 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy import select
 from typing import Optional
 
-from db.models import Order, OrderStatus
+from sqlalchemy.orm import selectinload
+
+from db.models import Order, OrderStatus, OrderItem
 
 
 class OrderRepository:
@@ -28,6 +30,7 @@ class OrderRepository:
             .where(Order.customer == customer)
             .where(Order.status == OrderStatus.DRAFT)
             .limit(1)
+            .options(selectinload(Order.items).selectinload(OrderItem.product))
         )
         return await session.scalar(stmt)
 

services/orders.py

@@ -1,6 +1,8 @@
 import logging
 from sqlalchemy.ext.asyncio import AsyncSession
+from config import PAGE_SIZE
 from db.models.orders import OrderStatus
+from dto.cart import CartDTO, CartItemDTO
 from repositories.order_items import OrderItemRepository
 from repositories.orders import OrderRepository
 
@@ -44,6 +46,7 @@ class OrderService:
             order_item = await self.order_items_repo.create_order_item(
                 session, order_id=order.id, product_id=product_id, quantity=quantity
             )
+            return quantity
         else:
             await self.order_items_repo.update_order_item_quantity(
                 session, order_item.id, quantity=order_item.quantity + quantity
@@ -75,13 +78,37 @@ class OrderService:
                 "attempt of decreasing quantity of non-existing order_item, potential callback_query exploit, ignoring..."
             )
 
-        new_quantity = max(0, order_item.quantity - quantity)
+        new_quantity = order_item.quantity - quantity
+        if new_quantity > 0:
             await self.order_items_repo.update_order_item_quantity(
                 session, order_item_id=order_item.id, quantity=new_quantity
             )
+        else:
+            await self.order_items_repo.delete_item(session, order_item.id)
 
         return new_quantity
 
+    async def clear_from_cart(
+        self, session: AsyncSession, *, customer: int, product_id: int
+    ):
+        order = await self.order_repo.get_draft_order_by_user(session, customer)
+
+        if not order:
+            raise OrderServiceException(
+                "attempt of removing product from non-existing cart, potential callback_query exploit, ignoring..."
+            )
+
+        order_item = await self.order_items_repo.get_item_by_order_and_product(
+            session, order_id=order.id, product_id=product_id
+        )
+
+        if not order_item:
+            raise OrderServiceException(
+                "attempt of decreasing quantity of non-existing order_item, potential callback_query exploit, ignoring..."
+            )
+
+        await self.order_items_repo.delete_item(session, item_id=order_item.id)
+
     async def get_cart_product_amount(
         self, session: AsyncSession, *, customer: int, product_id: int
     ) -> int:
@@ -127,7 +154,40 @@ class OrderService:
         if not order:
             return 0
 
-        order_item = await self.order_items_repo.get_items_by_order(
-            session, order_id=order.id
+        return await self.order_items_repo.get_items_count(session, order_id=order.id)
+
+    async def build_cart_dto(
+        self,
+        session: AsyncSession,
+        *,
+        customer: int,
+        limit: int = PAGE_SIZE + 1,
+        offset: int = 0,
+    ) -> CartDTO:
+        order = await self.order_repo.get_draft_order_by_user(session, customer)
+        cart_items = []
+
+        if not order:
+            return CartDTO(items=cart_items, total=0)
+
+        order_items = await self.order_items_repo.get_items_by_order(
+            session, order_id=order.id, limit=limit, offset=offset
         )
-        return len(order_item)
+
+        total = 0
+
+        for item in order_items:
+            if item.quantity <= 0:
+                await self.order_items_repo.delete_item(session, item_id=item.id)
+                continue
+
+            cart_item = CartItemDTO(
+                product_id=item.product_id,
+                name=item.product.name,
+                quantity=item.quantity,
+                price=item.product.price,
+            )
+            cart_items.append(cart_item)
+            total += cart_item.total
+
+        return CartDTO(items=cart_items, total=total)

startup.sh

@@ -3,6 +3,7 @@
 set -e
 
 echo "formatting..."
+ruff check . --fix
 black .
 
 echo "checking psql..."