import uuid

from sqlalchemy import (
    Boolean,
    Column,
    DateTime,
    Float,
    ForeignKey,
    String,
    Text,
)
from sqlalchemy.orm import relationship
from sqlalchemy.sql import func

from app.db.base import Base


class Category(Base):
    """Category model for product categorization."""
    __tablename__ = "categories"

    id = Column(String, primary_key=True, index=True, default=lambda: str(uuid.uuid4()))
    name = Column(String, unique=True, index=True, nullable=False)
    description = Column(Text, nullable=True)
    
    # Relationships
    products = relationship("Product", back_populates="category")
    
    # Audit timestamps
    created_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
    updated_at = Column(DateTime(timezone=True), server_default=func.now(), onupdate=func.now(), nullable=False)


class Product(Base):
    """Product model."""
    __tablename__ = "products"

    id = Column(String, primary_key=True, index=True, default=lambda: str(uuid.uuid4()))
    name = Column(String, index=True, nullable=False)
    description = Column(Text, nullable=True)
    price = Column(Float, nullable=False)
    sku = Column(String, unique=True, index=True, nullable=False)
    is_active = Column(Boolean, default=True)
    
    # Foreign keys
    category_id = Column(String, ForeignKey("categories.id"), nullable=True)
    
    # Relationships
    category = relationship("Category", back_populates="products")
    inventory_items = relationship("InventoryItem", back_populates="product")
    
    # Audit timestamps
    created_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
    updated_at = Column(DateTime(timezone=True), server_default=func.now(), onupdate=func.now(), nullable=False)