alter table public.workspace_billing_accounts
  add column if not exists grace_period_ends_at timestamptz,
  add column if not exists pending_plan_code text,
  add column if not exists pending_plan_effective_at timestamptz,
  add column if not exists billing_sync_status text not null default 'ok' check (billing_sync_status in ('ok', 'stale', 'error')),
  add column if not exists last_stripe_sync_at timestamptz;

create table if not exists public.workspace_billing_timeline_events (
  id uuid primary key default gen_random_uuid(),
  workspace_id uuid not null references public.workspaces (id) on delete cascade,
  billing_account_id uuid references public.workspace_billing_accounts (id) on delete set null,
  event_type text not null check (
    event_type in (
      'checkout_completed',
      'subscription_created',
      'subscription_updated',
      'subscription_deleted',
      'invoice_paid',
      'invoice_payment_failed',
      'portal_returned',
      'checkout_returned',
      'addon_purchased',
      'billing_status_changed',
      'plan_change_scheduled'
    )
  ),
  source text not null check (source in ('stripe', 'app', 'system')),
  payload_json jsonb not null default '{}'::jsonb,
  external_event_id text,
  external_customer_ref text,
  external_subscription_ref text,
  occurred_at timestamptz not null default now(),
  created_at timestamptz not null default now(),
  updated_at timestamptz not null default now()
);

create index if not exists workspace_billing_accounts_pending_plan_idx on public.workspace_billing_accounts (pending_plan_code);
create index if not exists workspace_billing_accounts_sync_status_idx on public.workspace_billing_accounts (billing_sync_status);
create index if not exists workspace_billing_timeline_events_workspace_id_idx on public.workspace_billing_timeline_events (workspace_id, occurred_at desc);
create index if not exists workspace_billing_timeline_events_event_type_idx on public.workspace_billing_timeline_events (event_type);
create index if not exists workspace_billing_timeline_events_subscription_ref_idx on public.workspace_billing_timeline_events (external_subscription_ref);

drop trigger if exists set_workspace_billing_timeline_events_updated_at on public.workspace_billing_timeline_events;
create trigger set_workspace_billing_timeline_events_updated_at
before update on public.workspace_billing_timeline_events
for each row
execute function public.set_updated_at();