// The Team forum's client-side judgements — the few there are (TEAMS.md Part 5).
//
// This file is small on purpose. **Almost nothing about the forum is the
// client's to decide**: who may post, who may moderate, whether an image
// renders, and whether a post may be edited are all answered by the server and
// read from the payload. What is left here is the handful of pure functions that
// turn those answers into what a reader sees, and they are extracted so they can
// be tested without a browser.
//
// The one that deserves a second look is `editOfferOpen`. It can only ever take
// an offer AWAY — the server grants the edit and re-derives the window from
// `created_at` when the write arrives. A client that granted one would be
// deciding a time-bounded permission against the clock of the party it bounds.

export const REPORT_REASONS = [
  ['abuse', 'Abusive or harassing'],
  ['spam', 'Spam'],
  ['sexual', 'Sexual content'],
  ['illegal', 'Illegal content'],
  ['impersonation', 'Impersonation'],
  ['other', 'Something else'],
]

/**
 * Should the Edit control still be offered for this post?
 *
 * Three states, and the middle one is the reason this exists:
 *   • the server said no        → no offer, and nothing here can create one
 *   • the server said yes, no deadline (staff) → offer
 *   • the server said yes with a deadline that has since passed while the page
 *     sat open → withdraw the offer, rather than leave a button that fails
 */
export function editOfferOpen(post, now = Date.now()) {
  if (!post || !post.canEdit) return false
  if (!post.editableUntil) return true
  const until = new Date(post.editableUntil).getTime()
  return Number.isFinite(until) && until > now
}

/**
 * Turn a rendered body back into something an author can edit.
 *
 * The server stores sanitised HTML and generates images at READ time from the
 * URLs an author wrote (§5.5.3), so what comes back is not what was typed. The
 * `<img>` has to go — it is core's output, not the author's input, and leaving it
 * in would let an author "edit" markup they never wrote and cannot control.
 * The URL survives as the link text beside it, which is what re-renders.
 */
export function stripToText(html) {
  return String(html || '')
    .replace(/<img[^>]*>/gi, '')
    .replace(/<\/p>\s*<p[^>]*>/gi, '\n\n')
    .replace(/<br\s*\/?>/gi, '\n')
    .replace(/<[^>]*>/g, '')
    // Entities last: unescaping before tag-stripping would let an escaped
    // "&lt;script&gt;" become a real tag the next pass then removes, which is a
    // different string from the one the author wrote.
    .replace(/&lt;/g, '<')
    .replace(/&gt;/g, '>')
    .replace(/&quot;/g, '"')
    .replace(/&#39;/g, "'")
    .replace(/&nbsp;/g, ' ')
    // `&amp;` last of all, or "&amp;lt;" would decode two steps into "<".
    .replace(/&amp;/g, '&')
    .trim()
}

/**
 * The one-line summary under a thread's title in the list.
 *
 * `postCount` counts every post including the opening one, so a discussion's
 * REPLY count is one less — and an announcement has no replies to count at all,
 * which is why the count is omitted rather than shown as zero.
 */
export function threadSummary(thread) {
  const parts = []
  if (thread.type === 'announcement') parts.push('Announcement')
  parts.push(thread.author)
  if (thread.type === 'discussion' && thread.postCount > 1) {
    const replies = thread.postCount - 1
    parts.push(`${replies} ${replies === 1 ? 'reply' : 'replies'}`)
  }
  if (thread.status === 'hidden') parts.push('hidden')
  return parts.join(' · ')
}