from app.db.memory import (
    create_booking as db_create_booking,
    get_busy_times as db_get_busy_times,
    get_user_bookings as db_get_user_bookings,
    cancel_booking as db_cancel_booking,
    update_booking as db_update_booking,
    load_bookings as db_load_bookings,
    save_bookings as db_save_bookings,
    BOOKINGS_FILE,
)
from app.logger import logger


async def create_booking(user_id, service, master, date, time, user_name=""):
    return db_create_booking(user_id, service, master, date, time, user_name)


async def get_busy_times(master, date):
    return db_get_busy_times(master, date)


async def get_user_bookings(user_id):
    return db_get_user_bookings(user_id)


async def cancel_booking(booking_id):
    return db_cancel_booking(booking_id)


async def update_booking(booking_id, service, master, date, time):
    return db_update_booking(booking_id, service, master, date, time)


async def is_slot_busy(master, date, time):
    """Check if a time slot is already taken by an active booking."""
    busy = db_get_busy_times(master, date)
    return time in busy


def cleanup_cancelled():
    """Remove cancelled bookings older than the head (keep only last 5 cancelled per user)."""
    bookings = db_load_bookings()
    active = [b for b in bookings if b["status"] == "active"]
    cancelled = [b for b in bookings if b["status"] == "cancelled"]

    # Group cancelled by user, keep last 5 per user
    from collections import defaultdict
    by_user = defaultdict(list)
    for b in cancelled:
        by_user[b["user_id"]].append(b)

    keep_ids = set()
    for uid, user_cancel in by_user.items():
        # Keep the 5 most recent
        user_cancel.sort(key=lambda x: x.get("id", 0), reverse=True)
        for b in user_cancel[:5]:
            keep_ids.add(b["id"])

    # Rebuild: keep active + keep recent cancelled
    bookings = active + [b for b in cancelled if b["id"] in keep_ids]
    db_save_bookings(bookings)
    removed = len(cancelled) - len(keep_ids)
    if removed > 0:
        logger.info("Cleaned up {n} old cancelled bookings", n=removed)