alter table public.tasks
  add column if not exists help_requested_to_user_id uuid null,
  add column if not exists help_requested_by_user_id uuid null,
  add column if not exists help_requested_at timestamptz null;

alter table public.task_steps
  add column if not exists help_requested_to_user_id uuid null,
  add column if not exists help_requested_by_user_id uuid null,
  add column if not exists help_requested_at timestamptz null;

do $$
begin
  if not exists (
    select 1 from pg_constraint where conname = 'tasks_help_requested_to_user_id_fkey'
  ) then
    alter table public.tasks
      add constraint tasks_help_requested_to_user_id_fkey
      foreign key (help_requested_to_user_id) references public.users(id);
  end if;

  if not exists (
    select 1 from pg_constraint where conname = 'tasks_help_requested_by_user_id_fkey'
  ) then
    alter table public.tasks
      add constraint tasks_help_requested_by_user_id_fkey
      foreign key (help_requested_by_user_id) references public.users(id);
  end if;

  if not exists (
    select 1 from pg_constraint where conname = 'task_steps_help_requested_to_user_id_fkey'
  ) then
    alter table public.task_steps
      add constraint task_steps_help_requested_to_user_id_fkey
      foreign key (help_requested_to_user_id) references public.users(id);
  end if;

  if not exists (
    select 1 from pg_constraint where conname = 'task_steps_help_requested_by_user_id_fkey'
  ) then
    alter table public.task_steps
      add constraint task_steps_help_requested_by_user_id_fkey
      foreign key (help_requested_by_user_id) references public.users(id);
  end if;
end $$;

create index if not exists tasks_help_requested_to_user_id_idx
  on public.tasks(help_requested_to_user_id);

create index if not exists tasks_help_requested_by_user_id_idx
  on public.tasks(help_requested_by_user_id);

create index if not exists task_steps_help_requested_to_user_id_idx
  on public.task_steps(help_requested_to_user_id);

create index if not exists task_steps_help_requested_by_user_id_idx
  on public.task_steps(help_requested_by_user_id);