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

models/scenario.py

@@ -0,0 +1,67 @@
+from __future__ import annotations
+
+from datetime import date, datetime
+from enum import Enum
+from typing import TYPE_CHECKING, List
+
+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 .financial_input import FinancialInput
+    from .project import Project
+    from .simulation_parameter import SimulationParameter
+
+
+class ScenarioStatus(str, Enum):
+    """Lifecycle states for project scenarios."""
+
+    DRAFT = "draft"
+    ACTIVE = "active"
+    ARCHIVED = "archived"
+
+
+class Scenario(Base):
+    """A specific configuration of assumptions for a project."""
+
+    __tablename__ = "scenarios"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, index=True)
+    project_id: Mapped[int] = mapped_column(
+        ForeignKey("projects.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+    name: Mapped[str] = mapped_column(String(255), nullable=False)
+    description: Mapped[str | None] = mapped_column(Text, nullable=True)
+    status: Mapped[ScenarioStatus] = mapped_column(
+        SQLEnum(ScenarioStatus), nullable=False, default=ScenarioStatus.DRAFT
+    )
+    start_date: Mapped[date | None] = mapped_column(Date, nullable=True)
+    end_date: Mapped[date | None] = mapped_column(Date, nullable=True)
+    discount_rate: Mapped[float | None] = mapped_column(Numeric(5, 2), nullable=True)
+    currency: Mapped[str | None] = mapped_column(String(3), 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()
+    )
+
+    project: Mapped["Project"] = relationship("Project", back_populates="scenarios")
+    financial_inputs: Mapped[List["FinancialInput"]] = relationship(
+        "FinancialInput",
+        back_populates="scenario",
+        cascade="all, delete-orphan",
+        passive_deletes=True,
+    )
+    simulation_parameters: Mapped[List["SimulationParameter"]] = relationship(
+        "SimulationParameter",
+        back_populates="scenario",
+        cascade="all, delete-orphan",
+        passive_deletes=True,
+    )
+
+    def __repr__(self) -> str:  # pragma: no cover
+        return f"Scenario(id={self.id!r}, name={self.name!r}, project_id={self.project_id!r})"