alter table public.content_export_jobs
  drop constraint if exists content_export_jobs_format_check,
  drop constraint if exists content_export_jobs_status_check;

alter table public.content_export_jobs
  add constraint content_export_jobs_format_check
  check (format in ('json', 'paper_json', 'print_payload', 'pdf', 'docx'));

alter table public.content_export_jobs
  add constraint content_export_jobs_status_check
  check (status in ('pending', 'rendering', 'completed', 'failed'));

alter table public.content_export_jobs
  alter column status set default 'pending';

alter table public.content_export_jobs
  add column if not exists asset_id uuid references public.content_assets(id) on delete set null,
  add column if not exists locked_at timestamptz,
  add column if not exists locked_by text,
  add column if not exists attempt_count integer not null default 0,
  add column if not exists max_attempts integer not null default 3,
  add column if not exists next_attempt_at timestamptz,
  add column if not exists started_at timestamptz;

do $$
begin
  if not exists (select 1 from pg_constraint where conname = 'content_export_jobs_attempt_count_check') then
    alter table public.content_export_jobs
      add constraint content_export_jobs_attempt_count_check
      check (attempt_count >= 0 and max_attempts > 0 and attempt_count <= max_attempts);
  end if;
end $$;

create index if not exists idx_content_export_jobs_worker_queue
  on public.content_export_jobs(status, next_attempt_at, created_at)
  where status = 'pending';

create index if not exists idx_content_export_jobs_asset
  on public.content_export_jobs(tenant_id, asset_id)
  where asset_id is not null;