from __future__ import annotations
from datetime import time
from typing import Sequence

from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from models.calendars import CalendarSlot

class SlotError(ValueError):
    pass

def _b(v):
    if isinstance(v, bool):
        return v
    s = str(v).lower()
    return s in {"1","true","t","yes","y","on"}

async def list_slots(sess: AsyncSession, calendar_id: int) -> Sequence[CalendarSlot]:
    res = await sess.execute(
        select(CalendarSlot)
        .where(CalendarSlot.calendar_id == calendar_id, CalendarSlot.deleted_at.is_(None))
        .order_by(CalendarSlot.time_start.asc(), CalendarSlot.id.asc())
    )
    return res.scalars().all()

async def create_slot(
    sess: AsyncSession,
    calendar_id: int,
    *,
    name: str,
    description: str | None,
    days: dict,
    time_start: time,
    time_end: time,
    cost: float | None,
    flexible: bool = False,   # NEW
):
    if not name:
        raise SlotError("name is required")

    if not time_start or not time_end or time_end <= time_start:
        raise SlotError("time range invalid")

    slot = CalendarSlot(
        calendar_id=calendar_id,
        name=name,
        description=(description or None),
        mon=_b(days.get("mon")),
        tue=_b(days.get("tue")),
        wed=_b(days.get("wed")),
        thu=_b(days.get("thu")),
        fri=_b(days.get("fri")),
        sat=_b(days.get("sat")),
        sun=_b(days.get("sun")),
        time_start=time_start,
        time_end=time_end,
        cost=cost,
        flexible=flexible,   # NEW
    )
    sess.add(slot)
    await sess.flush()
    return slot