feat: add initial database models and changelog for financial inputs and projects

models/financial_input.py

@@ -0,0 +1,63 @@
+from __future__ import annotations
+
+from datetime import date, datetime
+from enum import Enum
+from typing import TYPE_CHECKING
+
+from sqlalchemy import (
+    Date,
+    DateTime,
+    Enum as SQLEnum,
+    ForeignKey,
+    Integer,
+    Numeric,
+    String,
+    Text,
+)
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+from sqlalchemy.sql import func
+
+from config.database import Base
+
+if TYPE_CHECKING:  # pragma: no cover
+    from .scenario import Scenario
+
+
+class FinancialCategory(str, Enum):
+    """Enumeration of cost and revenue classifications."""
+
+    CAPITAL_EXPENDITURE = "capex"
+    OPERATING_EXPENDITURE = "opex"
+    REVENUE = "revenue"
+    CONTINGENCY = "contingency"
+    OTHER = "other"
+
+
+class FinancialInput(Base):
+    """Line-item financial assumption attached to a scenario."""
+
+    __tablename__ = "financial_inputs"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True)
+    scenario_id: Mapped[int] = mapped_column(
+        ForeignKey("scenarios.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+    name: Mapped[str] = mapped_column(String(255), nullable=False)
+    category: Mapped[FinancialCategory] = mapped_column(
+        SQLEnum(FinancialCategory), nullable=False
+    )
+    amount: Mapped[float] = mapped_column(Numeric(18, 2), nullable=False)
+    currency: Mapped[str | None] = mapped_column(String(3), nullable=True)
+    effective_date: Mapped[date | None] = mapped_column(Date, nullable=True)
+    notes: Mapped[str | None] = mapped_column(Text, nullable=True)
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, server_default=func.now()
+    )
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, server_default=func.now(), onupdate=func.now()
+    )
+
+    scenario: Mapped["Scenario"] = relationship("Scenario", back_populates="financial_inputs")
+
+    def __repr__(self) -> str:  # pragma: no cover
+        return f"FinancialInput(id={self.id!r}, scenario_id={self.scenario_id!r}, name={self.name!r})"