-- Follow-up to 20260812105003 (deferred from the final whole-branch review
-- before merge). Postgres migrations are append-only history, so this
-- replaces the trigger function and the partial unique index rather than
-- editing the already-applied 20260812000002/20260812000003 files.
--
-- Problem: 20260812105003 widened bookings.status to allow 'completed', and
-- the admin panel gained a "Mark completed" action, but sync_booked_slot()
-- (20260812000003) and bookings_active_slot_idx (20260812000002) still only
-- treat status = 'confirmed' as "slot occupied". As a result:
--   1. confirmed -> completed deletes the booked_slots mirror row for that
--      slot, exactly as if the booking had been cancelled.
--   2. The partial unique index (where status = 'confirmed') no longer
--      blocks a second confirmed booking for a now-completed slot.
-- A completed appointment did happen and must continue to occupy its slot;
-- only 'cancelled' should free it.
--
-- Fix: every place sync_booked_slot() tested status = 'confirmed' now tests
-- status in ('confirmed', 'completed'), and the partial unique index is
-- rebuilt with the same predicate.
create or replace function public.sync_booked_slot()
returns trigger
language plpgsql
security definer
set search_path = ''
as $$
begin
  if tg_op = 'DELETE' then
    if old.status in ('confirmed', 'completed') then
      delete from public.booked_slots
      where date = old.date and time = old.time
        and not exists (
          select 1 from public.bookings b
          where b.date = old.date and b.time = old.time and b.status in ('confirmed', 'completed')
        );
    end if;
    return old;
  end if;

  if tg_op = 'UPDATE' then
    -- Covers both a status change away from 'confirmed'/'completed'
    -- (cancellation) and a reschedule of a still-occupying booking to a
    -- different (date, time): either way, the OLD slot may no longer have
    -- any confirmed/completed booking holding it and its mirror row needs
    -- to go.
    if old.status in ('confirmed', 'completed')
       and (old.date, old.time, old.status) is distinct from (new.date, new.time, new.status) then
      delete from public.booked_slots
      where date = old.date and time = old.time
        and not exists (
          select 1 from public.bookings b
          where b.date = old.date and b.time = old.time and b.status in ('confirmed', 'completed')
        );
    end if;
    if new.status in ('confirmed', 'completed') then
      insert into public.booked_slots (date, time)
      values (new.date, new.time)
      on conflict do nothing;
    end if;
    return new;
  end if;

  -- INSERT
  if new.status in ('confirmed', 'completed') then
    insert into public.booked_slots (date, time)
    values (new.date, new.time)
    on conflict do nothing;
  end if;
  return new;
end;
$$;

drop index if exists public.bookings_active_slot_idx;
create unique index bookings_active_slot_idx
  on public.bookings (date, time)
  where status in ('confirmed', 'completed');