feat: merge cartsnitch/api into api/ subdirectory

Consolidate API gateway service into monorepo.
Squashed from https://github.com/cartsnitch/api main (89bacb1).

Co-Authored-By: Paperclip <noreply@paperclip.ing>

src/cartsnitch_api/models/purchase.py

@@ -0,0 +1,91 @@
+"""Purchase and PurchaseItem models."""
+
+import uuid
+from datetime import date, datetime
+from decimal import Decimal
+from typing import TYPE_CHECKING
+
+from sqlalchemy import (
+    JSON,
+    Date,
+    DateTime,
+    ForeignKey,
+    Index,
+    Numeric,
+    String,
+    UniqueConstraint,
+    func,
+)
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from cartsnitch_api.models.base import Base, TimestampMixin, UUIDPrimaryKeyMixin
+
+if TYPE_CHECKING:
+    from cartsnitch_api.models.price import PriceHistory
+    from cartsnitch_api.models.product import NormalizedProduct
+    from cartsnitch_api.models.store import Store, StoreLocation
+    from cartsnitch_api.models.user import User
+
+
+class Purchase(UUIDPrimaryKeyMixin, TimestampMixin, Base):
+    """A single shopping trip / receipt."""
+
+    __tablename__ = "purchases"
+
+    user_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("users.id"), nullable=False)
+    store_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("stores.id"), nullable=False)
+    store_location_id: Mapped[uuid.UUID | None] = mapped_column(ForeignKey("store_locations.id"))
+    receipt_id: Mapped[str] = mapped_column(String(200), nullable=False)
+    purchase_date: Mapped[date] = mapped_column(Date, nullable=False)
+    total: Mapped[Decimal] = mapped_column(Numeric(10, 2), nullable=False)
+    subtotal: Mapped[Decimal | None] = mapped_column(Numeric(10, 2))
+    tax: Mapped[Decimal | None] = mapped_column(Numeric(10, 2))
+    savings_total: Mapped[Decimal | None] = mapped_column(Numeric(10, 2))
+    source_url: Mapped[str | None] = mapped_column(String(500))
+    raw_data: Mapped[dict | None] = mapped_column(JSON)
+    ingested_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True),
+        server_default=func.now(),
+        nullable=False,
+    )
+
+    # Relationships
+    user: Mapped["User"] = relationship(back_populates="purchases")
+    store: Mapped["Store"] = relationship(back_populates="purchases")
+    store_location: Mapped["StoreLocation | None"] = relationship(back_populates="purchases")
+    items: Mapped[list["PurchaseItem"]] = relationship(back_populates="purchase")
+
+    __table_args__ = (
+        Index("ix_purchases_user_store", "user_id", "store_id"),
+        UniqueConstraint("user_id", "store_id", "receipt_id", name="uq_purchase_receipt"),
+    )
+
+
+class PurchaseItem(UUIDPrimaryKeyMixin, TimestampMixin, Base):
+    """Individual line item on a receipt."""
+
+    __tablename__ = "purchase_items"
+
+    purchase_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("purchases.id"), nullable=False)
+    product_name_raw: Mapped[str] = mapped_column(String(300), nullable=False)
+    upc: Mapped[str | None] = mapped_column(String(20))
+    quantity: Mapped[Decimal] = mapped_column(Numeric(10, 3), nullable=False, default=1)
+    unit_price: Mapped[Decimal] = mapped_column(Numeric(10, 2), nullable=False)
+    extended_price: Mapped[Decimal] = mapped_column(Numeric(10, 2), nullable=False)
+    regular_price: Mapped[Decimal | None] = mapped_column(Numeric(10, 2))
+    sale_price: Mapped[Decimal | None] = mapped_column(Numeric(10, 2))
+    coupon_discount: Mapped[Decimal | None] = mapped_column(Numeric(10, 2))
+    loyalty_discount: Mapped[Decimal | None] = mapped_column(Numeric(10, 2))
+    category_raw: Mapped[str | None] = mapped_column(String(100))
+    normalized_product_id: Mapped[uuid.UUID | None] = mapped_column(
+        ForeignKey("normalized_products.id")
+    )
+
+    # Relationships
+    purchase: Mapped["Purchase"] = relationship(back_populates="items")
+    normalized_product: Mapped["NormalizedProduct | None"] = relationship(
+        back_populates="purchase_items"
+    )
+    price_history_entries: Mapped[list["PriceHistory"]] = relationship(
+        back_populates="purchase_item"
+    )