"""
Modelos ORM para gestión de clases SCAII y SCAF
"""
from sqlalchemy import Column, Integer, String, DateTime, Boolean, Text, Numeric, SmallInteger, ForeignKey
from sqlalchemy.sql import func
from sqlalchemy.orm import relationship
from core.database import Base
import enum

# Importar modelos relacionados para type hints y relationships
from typing import TYPE_CHECKING, List, Optional

if TYPE_CHECKING:
    from api.v1.modules.a76.parts.models import Part
    from api.v1.modules.public.reference_data.material_types.models import MaterialType


class Class(Base):
    """
    Modelo para la tabla GClases - Información de clases en sistemas SCAII y SCAF
    """
    __tablename__ = "classes"
    __table_args__ = {"schema": "a76"}
    
    # Primary key compuesta
    client_key = Column(Integer, primary_key=True, nullable=False)
    class_code = Column(String(8), primary_key=True, nullable=False)
    
    # Basic information
    description_spanish = Column(String(500), nullable=True)
    description_english = Column(String(500), nullable=True)
    
    # Material and measurement
    material_key = Column(String(10), ForeignKey('public.material_types.key'), nullable=True)  # CLAVEMAT - homologated from TIPOMAT/TIPOMATEQUIPO
    unit_of_measure = Column(String(5), nullable=True)  # UNIMED - homologated from UNIMEDIDA
    
    # Tariff fractions
    fraction = Column(String(10), nullable=True)  # Mexican tariff fraction
    us_fraction = Column(String(16), nullable=True)  # FRACCIONAME - US tariff fraction
    
    # Additional classification
    sub_key = Column(String(5), nullable=True)  # CLAVESUB
    physical_review = Column(SmallInteger, nullable=True)  # REVFISICA
    iva_exempt_fraction = Column(String(4), nullable=True)  # FRACCIONEXENTAIVA
    
    # Relationships
    material_type = relationship("MaterialType", foreign_keys=[material_key])
    
    # Inverse relationship with GParts that have this class
    parts = relationship(
        "Part",
        primaryjoin="and_(Class.client_key == Part.client_key, Class.class_code == Part.part_class)",
        foreign_keys="[Part.client_key, Part.part_class]",
        viewonly=True,
        back_populates="part_class_info"
    )
    
    def __repr__(self):
        return f"<Class(client_key={self.client_key}, class_code='{self.class_code}', description='{self.description_spanish}')>"