from sqlalchemy import Column, Integer, Float, DateTime, ForeignKey, Text
from sqlalchemy.orm import relationship
from datetime import datetime, timezone
from database import Base


def _utcnow():
    return datetime.now(timezone.utc)


class WaiterShift(Base):
    __tablename__ = "waiter_shifts"

    id = Column(Integer, primary_key=True, index=True)
    waiter_id = Column(Integer, ForeignKey("users.id"), nullable=False)
    business_day_id = Column(Integer, ForeignKey("business_days.id"), nullable=False)
    started_at = Column(DateTime(timezone=True), default=_utcnow, nullable=False)
    ended_at = Column(DateTime(timezone=True), nullable=True)
    starting_cash = Column(Float, nullable=True)
    total_collected = Column(Float, nullable=True)  # snapshot written at shift end
    notes = Column(Text, nullable=True)

    waiter = relationship("User", foreign_keys=[waiter_id])
    business_day = relationship("BusinessDay", back_populates="shifts")
    breaks = relationship("ShiftBreak", back_populates="shift", cascade="all, delete-orphan")


class ShiftBreak(Base):
    __tablename__ = "shift_breaks"

    id = Column(Integer, primary_key=True, index=True)
    shift_id = Column(Integer, ForeignKey("waiter_shifts.id"), nullable=False)
    started_at = Column(DateTime(timezone=True), default=_utcnow, nullable=False)
    ended_at = Column(DateTime(timezone=True), nullable=True)

    shift = relationship("WaiterShift", back_populates="breaks")