/**
 * The journal of what the automation wrote, in the merchant's words: who
 * wrote it, which field, and the values as they read on screen.
 */

const SOURCES: Record<string, string> = {
  agent: 'SEO medic',
  copilot: 'Copilot',
  checkup: 'Checkup fix',
  publish: 'Article publishing',
  backfill: 'Imported articles',
  writer: 'SEO tools',
  editor: 'Fix with AI',
  images: 'Image tools',
  toolbar: 'Admin bar',
  import: 'Import from another plugin',
  bulk: 'Bulk Edit in a post list',
  quick: 'Quick Edit in a post list',
};

const META_FIELDS: Record<string, string> = {
  _recomaze_seo_title: 'SEO title',
  _recomaze_seo_description: 'Meta description',
  _recomaze_seo_focus_keywords: 'Focus keywords',
  _recomaze_seo_robots: 'Robots',
  _recomaze_seo_advanced_robots: 'Advanced robots',
  _recomaze_seo_canonical: 'Canonical URL',
  _recomaze_seo_breadcrumb_title: 'Breadcrumb title',
  _recomaze_seo_og_title: 'Social title',
  _recomaze_seo_og_description: 'Social description',
  _recomaze_seo_og_image: 'Social image',
  _recomaze_seo_og_image_id: 'Social image',
  _recomaze_seo_og_overlay: 'Badge on the social image',
  _recomaze_seo_tw_title: 'X title',
  _recomaze_seo_tw_description: 'X description',
  _recomaze_seo_tw_image: 'X image',
  _recomaze_seo_tw_image_id: 'X image',
  _recomaze_seo_tw_custom: 'Own X fields',
  _recomaze_seo_exclude_sitemap: 'Excluded from the sitemap',
  _recomaze_seo_pillar: 'Pillar content',
  _recomaze_seo_schema: 'Schema added on the post',
  _recomaze_seo_schema_custom: 'Custom schema (JSON-LD)',
  _recomaze_seo_brand: 'Brand',
  _recomaze_seo_gtin: 'GTIN',
  _recomaze_seo_mpn: 'MPN',
  _recomaze_seo_isbn: 'ISBN',
  _recomaze_seo_condition: 'Condition',
  _recomaze_seo_availability: 'Availability',
  _recomaze_seo_facebook: 'Facebook profile',
  _recomaze_seo_x: 'X username',
  _recomaze_seo_profiles: 'Other profiles',
  _recomaze_schema_faq_jsonld: 'FAQ schema',
  _recomaze_schema_article_jsonld: 'Article schema',
};

const OTHER_FIELDS: Record<string, string> = {
  'media.alt': 'Alt text',
  'media.title': 'Image title',
  'media.caption': 'Caption',
  'post_field.post_title': 'Title',
  'post_field.post_content': 'Content',
  'post_field.post_excerpt': 'Short description',
  'post_terms.product_tag': 'Product tags',
  'post_terms.post_tag': 'Tags',
  'wp_option.blog_public': 'Search engines may index the site',
  'option.general.robots_txt': 'robots.txt text',
  'option.general.robots_ai_allow': 'AI crawlers allowed',
  'option.general.robots_ai_block': 'AI crawlers blocked',
  'option.general.disable_xmlrpc': 'XML-RPC switched off',
  'option.sitemap.ping_indexnow': 'Notify IndexNow on publish',
};

const humanize = (key: string): string => {
  const text = key
    .replace(/^_+/, '')
    .replace(/[_.-]+/g, ' ')
    .trim();
  return text.charAt(0).toUpperCase() + text.slice(1);
};

export const sourceLabel = (source: string): string =>
  SOURCES[source] ?? humanize(source);

/**
 * @param {string} objectType - post, term, user, media, post_field, post_terms, option, wp_option, module or redirect.
 * @param {string} field      - The meta key, column, option key or module slug.
 * @returns {string} The field as a merchant knows it.
 */
export const fieldLabel = (objectType: string, field: string): string => {
  if (META_FIELDS[field]) {
    return META_FIELDS[field];
  }
  const known = OTHER_FIELDS[`${objectType}.${field}`];
  if (known) {
    return known;
  }
  if (objectType === 'module') {
    return `Module: ${humanize(field)}`;
  }
  if (objectType === 'redirect') {
    return 'Redirect';
  }
  if (objectType === 'option') {
    return humanize(field.split('.').pop() ?? field);
  }
  return humanize(field);
};

/**
 * @param {unknown} value - A value before or after a change.
 * @returns {string} On and Off for switches, lists joined, empty as a dash.
 */
export const valueLabel = (value: unknown): string => {
  if (value === null || value === undefined || value === '') {
    return '—';
  }
  if (typeof value === 'boolean') {
    return value ? 'On' : 'Off';
  }
  if (Array.isArray(value)) {
    return value.length === 0 ? '—' : value.map(String).join(', ');
  }
  const text = typeof value === 'string' ? value : JSON.stringify(value);
  return text.length > 80 ? `${text.slice(0, 77)}…` : text;
};

/** Up to this long, a text change reads whole in its cell. */
const SHORT_TEXT = 80;

/** How much of the unchanged text is shown on each side of a change. */
const CONTEXT = 60;

/** Longer removed or added text is cut in the middle. */
const LONGEST_PART = 240;

/** One run of a change's excerpt: text kept around it, removed or added. */
export interface ChangePart {
  type: 'same' | 'del' | 'add';
  text: string;
}

const cutMiddle = (text: string): string =>
  text.length > LONGEST_PART
    ? `${text.slice(0, LONGEST_PART - 80)} … ${text.slice(-60)}`
    : text;

/**
 * The part of a long text that a change touched, with a little of the text
 * around it: a link fix in a whole post reads as the link that changed, not
 * as the first characters of the post. The edges move out to whole words so
 * a changed address or word reads whole.
 *
 * @param {unknown} before - The value before the change.
 * @param {unknown} after  - The value after it.
 * @returns {ChangePart[] | null} The excerpt, or null when both values are short or not text.
 */
export const changeExcerpt = (
  before: unknown,
  after: unknown
): ChangePart[] | null => {
  const a = typeof before === 'string' ? before : before == null ? '' : null;
  const b = typeof after === 'string' ? after : after == null ? '' : null;
  if (a === null || b === null || a === b) {
    return null;
  }
  if (a.length <= SHORT_TEXT && b.length <= SHORT_TEXT) {
    return null;
  }
  const shortest = Math.min(a.length, b.length);
  let start = 0;
  while (start < shortest && a[start] === b[start]) start += 1;
  let end = 0;
  while (
    end < shortest - start &&
    a[a.length - 1 - end] === b[b.length - 1 - end]
  ) {
    end += 1;
  }
  const boundary = /\s/;
  while (start > 0 && !boundary.test(a[start - 1])) start -= 1;
  while (end > 0 && !boundary.test(a[a.length - end])) end -= 1;

  const leftFrom = Math.max(0, start - CONTEXT);
  const left =
    (leftFrom > 0 ? '…' : '') +
    a.slice(leftFrom, start).replace(leftFrom > 0 ? /^\S*\s/ : /^/, '');
  const rightTo = Math.min(a.length, a.length - end + CONTEXT);
  const right =
    a
      .slice(a.length - end, rightTo)
      .replace(rightTo < a.length ? /\s\S*$/ : /$/, '') +
    (rightTo < a.length ? '…' : '');

  const parts: ChangePart[] = [];
  if (left) parts.push({ type: 'same', text: left });
  const removed = a.slice(start, a.length - end);
  const added = b.slice(start, b.length - end);
  if (removed) parts.push({ type: 'del', text: cutMiddle(removed) });
  if (added) parts.push({ type: 'add', text: cutMiddle(added) });
  if (right) parts.push({ type: 'same', text: right });
  return parts;
};