/**
 * Cheap, explainable "is this pin junk?" signals.
 *
 * Shared by the admin review queue and its Settings card so the two never drift.
 * These are HEURISTICS, not verdicts: every one of them is something a human can
 * check in about two seconds, and the action they drive (a reversible NIP-32
 * label) is a suggestion-taking, never a deletion.
 */
import type { SkateSpot } from '@/lib/types';

/** Names that almost always mean a test entry or an off-topic pin. */
const SUSPICIOUS_TITLE =
  /(^|\b)(test|testing|asdf|asd|qwerty|foo|bar|untitled|demo|sample|example|secret|airport|my (house|home|flat|apartment))(\b|$)/i;

/** The minimum any reviewable entity can tell us (any kind). */
export interface ContentQualityInput {
  title?: string;
  description?: string;
  /** How many pictures the entity carries (0 = none). */
  imageCount?: number;
  /** Whether it has a usable location (spots/shops/events/tours). */
  hasLocation?: boolean;
}

/**
 * Kind-agnostic junk signals, so the review queue can cover shops, events,
 * tours and listings without a copy of the logic per kind.
 */
export function contentFlags(input: ContentQualityInput): string[] {
  const flags: string[] = [];
  const title = (input.title ?? '').trim();
  const description = (input.description ?? '').trim();

  if (SUSPICIOUS_TITLE.test(title)) flags.push('suspicious name');
  if (title.length <= 3) flags.push('name too short');
  if ((input.imageCount ?? 0) === 0) flags.push('no photo');
  if (description.length < 10) flags.push('no description');
  if (input.hasLocation === false) flags.push('no location');

  return flags;
}

export interface SpotQualitySignals {
  /** Mapper's web-of-trust score (0–100), when known. */
  mapperTrust?: number;
  /** Status reports (kind 2259) from skaters — a real "someone was here" signal. */
  communityStatusReports?: number;
  /** Community photos contributed by people other than the mapper. */
  communityPhotos?: number;
}

/** Every flag that applies, as short human-readable labels. */
export function spotFlags(spot: SkateSpot, extra: SpotQualitySignals = {}): string[] {
  const flags = contentFlags({
    title: spot.title,
    description: spot.description,
    imageCount: spot.images?.length ?? 0,
    hasLocation: !!spot.geohash,
  });

  // Signals that need extra data (passed in by the review queue).
  if (typeof extra.mapperTrust === 'number' && extra.mapperTrust <= 0) {
    flags.push('mapper not in your web of trust');
  }
  const communitySignals =
    (extra.communityStatusReports ?? 0) + (extra.communityPhotos ?? 0);
  if (communitySignals === 0 && flags.length > 0) {
    // Only meaningful alongside another flag: an unconfirmed spot with a real
    // name and a photo is just new, not junk.
    flags.push('no community signals');
  }

  return flags;
}

export function isFlagged(spot: SkateSpot): boolean {
  return spotFlags(spot).length > 0;
}