class VesselSystem(db.Model):
    __tablename__ = 'vessel_systems'
    id = db.Column(db.Integer, primary_key=True)
    vessel_id = db.Column(db.Integer, db.ForeignKey('vessels.id'))
    system_type = db.Column(db.String(50), nullable=False)  # propulsion, cubierta, puente, gobierno, generacion, electrico, etc
    component_name = db.Column(db.String(100), nullable=False)
    manufacturer = db.Column(db.String(100))
    model = db.Column(db.String(100))
    serial_number = db.Column(db.String(100))
    installation_date = db.Column(db.Date)
    last_maintenance_date = db.Column(db.Date)
    status = db.Column(db.String(20), default='active')
    notes = db.Column(db.Text)
    vessel = db.relationship('Vessel', backref='systems')

class MaintenanceLog(db.Model):
    __tablename__ = 'maintenance_logs'
    id = db.Column(db.Integer, primary_key=True)
    system_id = db.Column(db.Integer, db.ForeignKey('vessel_systems.id'))
    work_order_id = db.Column(db.Integer, db.ForeignKey('work_orders.id'))
    maintenance_date = db.Column(db.Date, nullable=False)
    maintenance_type = db.Column(db.String(50), nullable=False)  # preventivo, correctivo, inspeccion
    description = db.Column(db.Text)
    cost = db.Column(db.Float)
    technician = db.Column(db.String(100))
    next_maintenance_date = db.Column(db.Date)
    hours_accumulated = db.Column(db.Integer)
    system = db.relationship('VesselSystem', backref='maintenance_logs')