"""
Modelos ORM para gestión de clases SCAII y SCAF
"""
from typing import TYPE_CHECKING, Optional
from sqlalchemy import Integer, String, SmallInteger, ForeignKey, PrimaryKeyConstraint, ForeignKeyConstraint, UniqueConstraint
from sqlalchemy.orm import Mapped, mapped_column, relationship
from core.database import Base

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__ = (
        PrimaryKeyConstraint('id', name='classes_pkey'),
        UniqueConstraint('client_key', 'class_code', name='uq_classes_client_key_class_code'),
        ForeignKeyConstraint(['tenant_id'], ['a76.tenants.id'], name='fk_classes_tenant'),
        ForeignKeyConstraint(['material_key'], ['public.material_types.key'], name='fk_classes_material_type'),
        {"schema": "a76"}
    )    
    
    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    
    # Unique constraint compuesta
    client_key: Mapped[int] = mapped_column()
    class_code: Mapped[str] = mapped_column(String(8))
    
    tenant_id: Mapped[int] = mapped_column(Integer, nullable=False, index=True)
    
    # Basic information
    description_es: Mapped[Optional[str]] = mapped_column(String(500))
    description_en: Mapped[Optional[str]] = mapped_column(String(500))
    
    # Material and measurement
    material_key: Mapped[Optional[str]] = mapped_column(String(10), ForeignKey('public.material_types.key'))  # CLAVEMAT - homologated from TIPOMAT/TIPOMATEQUIPO
    unit_of_measure: Mapped[Optional[str]] = mapped_column(String(5))  # UNIMED - homologated from UNIMEDIDA
    
    # Tariff fractions
    fraction: Mapped[Optional[str]] = mapped_column(String(10))  # Mexican tariff fraction
    us_fraction: Mapped[Optional[str]] = mapped_column(String(16))  # FRACCIONAME - US tariff fraction
    
    # Additional classification
    sub_key: Mapped[Optional[str]] = mapped_column(String(5))  # CLAVESUB
    physical_review: Mapped[Optional[int]] = mapped_column(SmallInteger)  # REVFISICA
    iva_exempt_fraction: Mapped[Optional[str]] = mapped_column(String(4))  # FRACCIONEXENTAIVA
    
    # Relationships
    material_type: Mapped[Optional["MaterialType"]] = relationship(foreign_keys=[material_key])
    
    # Inverse relationship with GParts that have this class
    parts: Mapped[list["Part"]] = relationship(
        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) -> str:
        return f"<Class(client_key={self.client_key}, class_code='{self.class_code}', description='{self.description_es}')>"