// The layer's pagination and HTML-sitemap module options normalised for
// the runtime config (lib/seo-module.ts) and their readers in app and
// server code. Pure, so `node --test` drives it.

export interface SeoPaginationOption {
  form: 'query' | 'path'
  param: string
  segments: Record<string, string>
}

export type SeoHtmlSitemapOption = { paths: Record<string, string> } | false

/** The pagination option with its defaults, as the runtime config carries it. */
export function paginationOption(value: unknown): SeoPaginationOption {
  const v = value !== null && typeof value === 'object' ? (value as Record<string, unknown>) : {}
  const segments: Record<string, string> = {}
  const raw = v.segments !== null && typeof v.segments === 'object' ? (v.segments as Record<string, unknown>) : {}
  for (const [locale, segment] of Object.entries(raw)) if (typeof segment === 'string' && /^[\p{L}\p{N}_-]+$/u.test(segment)) segments[locale] = segment
  return {
    form: v.form === 'path' ? 'path' : 'query',
    param: typeof v.param === 'string' && /^[A-Za-z0-9_-]+$/.test(v.param) ? v.param : 'page',
    segments,
  }
}

/** The HTML sitemap option: false, or the paths (each '/' plus at least one character). */
export function htmlSitemapOption(value: unknown): SeoHtmlSitemapOption {
  if (value === false) return false
  const v = value !== null && typeof value === 'object' ? (value as Record<string, unknown>) : {}
  const paths: Record<string, string> = {}
  const raw = v.paths !== null && typeof v.paths === 'object' ? (v.paths as Record<string, unknown>) : {}
  for (const [locale, path] of Object.entries(raw)) {
    if (typeof path === 'string' && /^\/[^?#\s]+$/.test(path) && !path.includes(':') && !path.includes('*')) paths[locale] = path.replace(/\/+$/, '')
  }
  return { paths }
}