"""Portfolio model for WealthWise.

This module defines the Portfolio database model. Portfolios belong to users
and contain multiple transactions. Users can have multiple portfolios for
different investment strategies or purposes.
"""

from typing import TYPE_CHECKING, List, Optional
from uuid import UUID

from sqlalchemy import Column, ForeignKey, String, Text
from sqlmodel import Field, Relationship, SQLModel

from app.models.base import BaseModel

if TYPE_CHECKING:
    from app.models.transaction import Transaction
    from app.models.user import User


class PortfolioBase(SQLModel):
    """Base Portfolio model with common attributes.
    
    Attributes:
        name: Portfolio name
        description: Optional portfolio description
    """
    
    name: str = Field(
        sa_column=Column(String(255), nullable=False),
        description="Portfolio name",
    )
    description: Optional[str] = Field(
        default=None,
        sa_column=Column(Text, nullable=True),
        description="Optional portfolio description",
    )


class Portfolio(BaseModel, PortfolioBase, table=True):
    """Portfolio database model.
    
    Portfolios represent collections of financial transactions owned by a user.
    Each portfolio tracks investments, expenses, or savings for a specific purpose.
    
    Attributes:
        id: UUID primary key (inherited from BaseModel)
        user_id: Foreign key to users table
        name: Portfolio name
        description: Optional description
        user: Relationship to owner
        transactions: Relationship to portfolio transactions
        created_at: Timestamp (inherited from BaseModel)
        updated_at: Timestamp (inherited from BaseModel)
    """
    
    __tablename__ = "portfolios"
    
    user_id: UUID = Field(
        sa_column=Column(
            ForeignKey("users.id", ondelete="CASCADE"),
            nullable=False,
        ),
        description="Owner user ID",
    )
    
    # Relationships
    user: "User" = Relationship(back_populates="portfolios")
    transactions: List["Transaction"] = Relationship(
        back_populates="portfolio",
        sa_relationship_kwargs={"cascade": "all, delete-orphan"},
    )
    
    class Config:
        """Pydantic configuration."""
        arbitrary_types_allowed = True