// `orderChanges` — a post-commit subscriber on the `orders` table.
//
// Fires AFTER commit (the row IS written), best-effort + fire-and-forget
// (a throw logs and the next event still arrives; it can't back-pressure
// the change stream). Use it for reactions that aren't part of the
// write transaction — notify a fulfillment desk, mirror to a search
// index, bump a metric. `ctx.store` is there when the reaction needs to
// read or write; it runs as the SYSTEM subject (no request, so no
// tenant), which means a write to a `tenant()` table has to carry its
// `tenantId` explicitly — take it off the row that changed.
//
// For crash-safe multi-step reactions, use a `*.reaction.tsx`: a
// subscriber has no workflow handle, on purpose, because it is
// best-effort and a workflow kickoff should not be.
//
// `on: 'any'` matches insert / update / delete. `event.new` is present
// on insert + update (null on delete); `event.old` on update + delete
// (null on insert).

import { defineSubscriber } from '@voltro/runtime'

export default defineSubscriber({
  table: 'orders',
  on:    'any',
  handler: async (event, ctx) => {
    const row = (event.new ?? event.old) as { id?: string; status?: string } | null
    ctx.log.info('order changed', {
      op:     event.op,
      id:     row?.id,
      status: row?.status,
    })
  },
})