import type { CollectionBeforeChangeHook } from 'payload'

/**
 * Sets `publishedAt` to now the first time a document transitions to published,
 * if it isn't already set. Saves editors from filling the date manually and
 * keeps blog/article dates accurate for Article JSON-LD and sitemaps.
 *
 * Attach to collections with drafts enabled (blog, articles):
 *   hooks: { beforeChange: [setPublishedAtHook] }
 *
 * Only sets on the published transition; never overwrites an existing date
 * (an editor can still backdate manually).
 */
export const setPublishedAtHook: CollectionBeforeChangeHook = ({ data, originalDoc }) => {
  const becomingPublished = data._status === 'published' && originalDoc?._status !== 'published'
  if (becomingPublished && !data.publishedAt) {
    data.publishedAt = new Date().toISOString()
  }
  return data
}