-- CL3.5: background auto-sync lock primitives

create table if not exists public.job_locks (
  job_name text primary key,
  locked_at timestamptz not null default now(),
  locked_by text,
  expires_at timestamptz not null
);

create or replace function public.acquire_job_lock(
  p_job_name text,
  p_locked_by text,
  p_ttl_seconds integer default 240
)
returns boolean
language plpgsql
security definer
set search_path = public
as $$
declare
  v_acquired boolean := false;
begin
  insert into public.job_locks (job_name, locked_by, locked_at, expires_at)
  values (
    p_job_name,
    p_locked_by,
    now(),
    now() + make_interval(secs => p_ttl_seconds)
  )
  on conflict (job_name)
  do update
    set locked_by = excluded.locked_by,
        locked_at = excluded.locked_at,
        expires_at = excluded.expires_at
  where public.job_locks.expires_at < now();

  get diagnostics v_acquired = row_count;
  return v_acquired;
end;
$$;

create or replace function public.release_job_lock(p_job_name text)
returns void
language sql
security definer
set search_path = public
as $$
  delete from public.job_locks where job_name = p_job_name;
$$;