-- ============================================================
-- whatsapp_config: track Meta Cloud API registration state
--
-- Why this exists:
--   Saving a row to whatsapp_config does NOT make a phone number
--   actually receive webhook events from Meta. Two extra Cloud API
--   calls are required:
--
--     POST /{phone_number_id}/register     — subscribes the number
--                                            with a 2FA PIN, makes
--                                            it routable to OUR app
--     POST /{waba_id}/subscribed_apps      — subscribes the WABA
--                                            (one-time per app, but
--                                            idempotent so we can
--                                            call on every save)
--
--   Until those two complete successfully, Meta routes inbound
--   events to whichever app last registered the number (often the
--   one that did Embedded Signup originally). Symptom: a second
--   wacrm user adds a second number under the same WABA, the UI
--   reports "Connected" because metadata verification succeeds,
--   but Meta's activity log shows zero events for that number.
--
--   These columns let the UI distinguish "credentials saved" from
--   "actually live" and let users retry registration without
--   re-entering everything.
--
-- Backfill: every column is nullable. Existing rows survive with
-- NULL values; the UI shows them as "registration status unknown —
-- click Verify Registration" and the diagnostic endpoint fills the
-- timestamps on the next probe.
--
-- Idempotent — safe to re-run.
-- ============================================================

ALTER TABLE whatsapp_config
  ADD COLUMN IF NOT EXISTS registered_at TIMESTAMPTZ,
  ADD COLUMN IF NOT EXISTS subscribed_apps_at TIMESTAMPTZ,
  ADD COLUMN IF NOT EXISTS last_registration_error TEXT;

-- Index supports the "find all numbers awaiting registration"
-- query a future admin dashboard might want; cheap to maintain.
CREATE INDEX IF NOT EXISTS idx_whatsapp_config_registered_at
  ON whatsapp_config (registered_at)
  WHERE registered_at IS NULL;