from datetime import datetime
from sqlalchemy import Column, Integer, String, Boolean, ForeignKey, DateTime, Date
from sqlalchemy.orm import relationship
from app.db.base import Base

class VehicleModel(Base):
    """Reference table for Make/Model (e.g., Toyota Corolla)"""
    __tablename__ = "vehicle_models"
    __table_args__ = {"schema": "ref"}

    id = Column(Integer, primary_key=True, index=True)
    make = Column(String, nullable=False)
    model_name = Column(String, nullable=False)
    category = Column(String) # sedan, truck, van

class Vehicle(Base):
    """The physical asset"""
    __tablename__ = "vehicles"
    __table_args__ = {"schema": "data"}

    id = Column(Integer, primary_key=True, index=True)
    model_id = Column(Integer, ForeignKey("ref.vehicle_models.id"))
    
    vin = Column(String, unique=True, index=True, nullable=False)
    license_plate = Column(String, unique=True, index=True, nullable=False)
    production_year = Column(Integer)
    
    status = Column(String, default="active") # active, maintenance, sold
    created_at = Column(DateTime, default=datetime.utcnow)

    # Relationships
    history = relationship("VehicleHistory", back_populates="vehicle")

class VehicleHistory(Base):
    """
    Defines who is driving what and when.
    CRITICAL: This is the source of truth for 'Can User X see Vehicle Y?'
    """
    __tablename__ = "vehicle_history"
    __table_args__ = {"schema": "data"}

    id = Column(Integer, primary_key=True, index=True)
    vehicle_id = Column(Integer, ForeignKey("data.vehicles.id"), nullable=False)
    user_id = Column(Integer, ForeignKey("data.users.id"), nullable=False)
    
    role = Column(String, nullable=False) # owner, driver, fleet_manager
    
    start_date = Column(Date, nullable=False)
    end_date = Column(Date, nullable=True) # If NULL, the assignment is current
    
    is_active = Column(Boolean, default=True)

    vehicle = relationship("Vehicle", back_populates="history")