/**
 * The delivered copy: what a candidate becomes once it is on screen, plus the
 * two diagnoses the settings page prints about past deliveries.
 *
 * @module @dsh-plugin/session-notify/client/core/copy
 */

/**
 * Build the copy table for one translate function.
 * @param t - the translate function every string here goes through.
 * @returns `copyFor` (candidate → notice), `deliveryFacts` and `replayValue`
 *   (the two status values the settings page shows).
 */
export function createCopy(t) {
  /** Build the delivered copy for one candidate. */
  const copyFor = (candidate) => {
    const title = candidate.title === '' ? t('body.untitled') : candidate.title
    if (candidate.kind === 'completion') {
      // The heading already says what happened ("conversation finished"), so the
      // description is the conversation itself — naming it twice would only make
      // the card longer.
      return { kind: 'completion', title: t('notification.completion'), body: title }
    }
    // A plan review arrives as a question with its own discriminator, so it is
    // answered before the question branch below — a plan review says what it is,
    // rather than repeating the plan text the user has not read yet.
    if (candidate.pendingKind === 'plan-review') {
      return { kind: 'question', title: t('notification.question'), body: t('body.planReview', { title }) }
    }
    if (candidate.kind === 'question') {
      const question = candidate.detail
      return {
        kind: 'question',
        title: t('notification.question'),
        body: question === '' ? t('body.question', { title }) : `${title} · ${question}`,
      }
    }
    const tool = candidate.detail
    return {
      kind: 'approval',
      title: t('notification.approval'),
      body: tool === '' ? t('body.approvalPlain', { title }) : t('body.approval', { title, tool }),
    }
  }

  /**
   * Split the newest delivery into the three facts the status list shows.
   * @param last - `store.lastDelivery`.
   * @param tr - the translate function the outcome label is rendered with.
   * @returns `{ at, outcome, title }`, or null when nothing was ever delivered.
   */
  const deliveryFacts = (last, tr) => {
    if (last === null || last === undefined) return null
    const outcome = last.outcome.startsWith('system-refused')
      ? tr('config.diag.refused')
      : last.outcome === 'system'
        ? last.shown === true
          ? tr('config.diag.systemShown')
          : last.shown === false
            ? tr('config.diag.systemFailed')
            : tr('config.diag.systemUnconfirmed')
        : last.outcome === 'replay'
          ? tr('config.diag.replayDelivery')
          : tr('config.diag.popup')
    return { at: last.at, outcome, title: last.title ?? '' }
  }

  /** How many away-channel alerts are still waiting for the user to come back. */
  const replayValue = (count, tr) => (
    count === 0 ? tr('config.diag.replayNone') : tr('config.diag.replayValue', { count })
  )

  return { copyFor, deliveryFacts, replayValue }
}