from sqlalchemy import Column, String, Float, Integer, Text, DateTime
from sqlalchemy.sql import func
from database import Base


class Lamp(Base):
    """Marine navigation lamp catalog. Aids reference a Lamp by id; the
    battery warning/alarm thresholds for each Aid are computed from the
    lamp's voltage_min / voltage_max:
        warn  = voltage_min + (voltage_max - voltage_min) * 0.20
        alarm = voltage_min + (voltage_max - voltage_min) * 0.10
    """
    __tablename__ = "lamps"

    id              = Column(String, primary_key=True)
    manufacturer    = Column(String, nullable=False)
    model           = Column(String, nullable=False)
    lamp_count      = Column(Integer, default=1)
    voltage_min     = Column(Float, nullable=False)   # discharged threshold (V)
    voltage_max     = Column(Float, nullable=False)   # fully-charged nominal (V)
    notes           = Column(Text, nullable=True)
    creado_en       = Column(DateTime, server_default=func.now())
    modificado_en   = Column(DateTime, onupdate=func.now())