62 lines
1.9 KiB
Python
62 lines
1.9 KiB
Python
from sqlalchemy.orm import Mapped
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from sqlalchemy import select
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from sqlalchemy.ext.asyncio import AsyncSession
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from typing import AsyncIterator
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from .base import Base, CommonMixin
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class Product(Base, CommonMixin):
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"""Product."""
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name: Mapped[str]
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protein: Mapped[float]
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carb: Mapped[float]
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fat: Mapped[float]
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@property
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def calories(self) -> float:
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"""calories.
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:rtype: float
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"""
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return self.protein * 4 + self.carb * 4 + self.fat * 9
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@classmethod
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async def list_all(cls, session: AsyncSession, offset: int, limit: int):
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query = select(cls).offset(offset).limit(limit)
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stream = await session.stream_scalars(query.order_by(cls.id))
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async for row in stream:
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yield row
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@classmethod
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async def create(
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cls, session: AsyncSession, name: str, carb: float, protein: float, fat: float
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) -> "Product":
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# validation here
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assert carb <= 100, "carb must be less than 100"
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assert protein <= 100, "protein must be less than 100"
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assert fat <= 100, "fat must be less than 100"
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assert carb >= 0, "carb must be greater than 0"
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assert protein >= 0, "protein must be greater than 0"
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assert fat >= 0, "fat must be greater than 0"
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assert carb + protein + fat <= 100, "total must be less than 100"
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# to avoid duplicates in the database keep name as lower
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name = name.lower()
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# check if product already exists
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query = select(cls).where(cls.name == name)
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existing_product = await session.scalar(query)
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assert existing_product is None, "product already exists"
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product = Product(
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name=name,
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protein=protein,
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carb=carb,
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fat=fat,
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)
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session.add(product)
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await session.flush()
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return product
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