New models and first data on the landing page

src/allmende_payment_system/models.py

@@ -1,4 +1,8 @@
-from sqlalchemy import Column, ForeignKey, Table
+import datetime
+import decimal
+import typing
+
+from sqlalchemy import Column, ForeignKey, Numeric, Table
 from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column, relationship
 
 TABLE_PREFIX = "aps_"
@@ -18,10 +22,11 @@ class Account(Base):
         secondary=TABLE_PREFIX + "user_account_association",
         back_populates="accounts",
     )
+    transactions: Mapped[list["Transaction"]] = relationship("Transaction")
 
     @property
     def balance(self):
-        return 141.23
+        return sum(t.total_amount for t in self.transactions)
 
 
 user_account_association = Table(
@@ -41,3 +46,51 @@ class User(Base):
     accounts: Mapped[list["Account"]] = relationship(
         "Account", secondary=user_account_association, back_populates="users"
     )
+
+
+class Area(Base):
+    __tablename__ = TABLE_PREFIX + "area"
+    id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
+    name: Mapped[str] = mapped_column(nullable=False, unique=True)
+
+
+class Product(Base):
+    __tablename__ = TABLE_PREFIX + "product"
+    id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
+    name: Mapped[str] = mapped_column(nullable=False, unique=True)
+
+    price: Mapped[decimal.Decimal] = mapped_column(Numeric(10, 2))
+    # TODO: limit this to actually used vat rates?
+    vat_rate: Mapped[decimal.Decimal] = mapped_column(Numeric(10, 2))
+
+    area_id: Mapped[int] = mapped_column(ForeignKey(TABLE_PREFIX + "area.id"))
+    area: Mapped["Area"] = relationship("Area")
+
+
+TransactionTypes = typing.Literal[
+    "product",
+    "deposit",
+    "withdrawal",
+    "expense",
+]
+
+
+class Transaction(Base):
+    __tablename__ = TABLE_PREFIX + "transaction"
+    id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
+    type: Mapped[TransactionTypes] = mapped_column(nullable=False)
+    quantity: Mapped[decimal.Decimal] = mapped_column(Numeric(10, 2), nullable=True)
+    timestamp: Mapped[datetime.datetime] = mapped_column(
+        nullable=False, default=datetime.datetime.now()
+    )
+    total_amount: Mapped[decimal.Decimal] = mapped_column(
+        Numeric(10, 2), nullable=False
+    )
+
+    product_id: Mapped[int] = mapped_column(
+        ForeignKey(TABLE_PREFIX + "product.id"), nullable=True
+    )
+    product: Mapped["Product"] = relationship("Product")
+
+    account_id: Mapped[int] = mapped_column(ForeignKey(TABLE_PREFIX + "account.id"))
+    account: Mapped["Account"] = relationship("Account", back_populates="transactions")