/**
 * edit-surface.ts — SSOT of the « fiche unique » trigger.
 *
 * An entity whose view-set carries BOTH `detail` and `form` (and does not opt
 * out through `editExperience`/`uiDesign.editMode: 'direct'`) gets ONE fiche:
 * the DetailPage carries the read-first sections that toggle to edit IN PLACE
 * (« transformer la page en mode édition »), and the FormPage shrinks to
 * create-only. The `.edit` route then points at the DetailPage (all sections
 * opened on arrival).
 *
 * Deterministic, zero new pagespec field: the surface derives from the
 * view-set + the existing edit-mode opt-out, so every existing pagespec stays
 * valid — `detail` without `form` keeps the read-only fiche, `form` without
 * `detail` keeps the legacy create+edit FormPage, and 'direct' keeps the
 * legacy pair untouched.
 *
 * Imported by scaffold-component AND scaffold-routes (same drift-lock pattern
 * as lib/pwa-meta.ts) so the page emission and the route registration can
 * never disagree on which component serves `/edit`.
 */

export type EditSurface = 'unified' | 'legacy'

export function resolveEditSurface(
  entityViews: Iterable<string> | undefined,
  editMode: 'read-first' | 'direct',
): EditSurface {
  const views = new Set(entityViews ?? [])
  return views.has('detail') && views.has('form') && editMode === 'read-first'
    ? 'unified'
    : 'legacy'
}