// Validation for a user's synced Reader bookmarks and text highlights. The data comes
// from the browser, so everything is checked and malformed entries are dropped.
const COLOR = /^#[0-9a-fA-F]{3,8}$/;
const BOOKMARK_KEY = /^[1-3]?[A-Za-z]{2,3}-\d{1,3}-\d{1,3}$/; // e.g. "JHN-3-16", "1SA-3-5"
const BOOK = /^[1-3A-Za-z]{3}$/;
const MAX_BOOKMARKS = 5000;
const MAX_HIGHLIGHTS = 20000;
const MAX_NOTE = 500;

const int = (v, min, max) => Number.isInteger(v) && v >= min && v <= max;

// Returns { bookmarks, highlights } with only well-formed entries, or null when the body is
// not an object at all.
export function cleanMarks(body) {
  if (!body || typeof body !== 'object' || Array.isArray(body)) return null;

  const bookmarks = {};
  if (body.bookmarks && typeof body.bookmarks === 'object' && !Array.isArray(body.bookmarks)) {
    for (const [key, color] of Object.entries(body.bookmarks).slice(0, MAX_BOOKMARKS)) {
      if (BOOKMARK_KEY.test(key) && typeof color === 'string' && COLOR.test(color)) bookmarks[key] = color;
    }
  }

  // A short note on a bookmark: { "JHN-3-16": "my note" }
  const bookmarkNotes = {};
  if (body.bookmarkNotes && typeof body.bookmarkNotes === 'object' && !Array.isArray(body.bookmarkNotes)) {
    for (const [key, note] of Object.entries(body.bookmarkNotes).slice(0, MAX_BOOKMARKS)) {
      if (BOOKMARK_KEY.test(key) && typeof note === 'string' && note.trim()) bookmarkNotes[key] = note.slice(0, MAX_NOTE);
    }
  }

  const highlights = [];
  if (Array.isArray(body.highlights)) {
    const seen = new Set();
    for (const h of body.highlights.slice(0, MAX_HIGHLIGHTS)) {
      if (!h || typeof h !== 'object') continue;
      if (typeof h.id !== 'string' || h.id.length === 0 || h.id.length > 64 || seen.has(h.id)) continue;
      if (!BOOK.test(String(h.book)) || !int(h.chapter, 1, 200) || !int(h.verse, 1, 200)) continue;
      if (!int(h.startOffset, 0, 5000) || !int(h.endOffset, 1, 5000) || h.endOffset <= h.startOffset) continue;
      if (typeof h.color !== 'string' || !COLOR.test(h.color)) continue;
      seen.add(h.id);
      const entry = {
        id: h.id, book: String(h.book).toUpperCase(), chapter: h.chapter, verse: h.verse,
        startOffset: h.startOffset, endOffset: h.endOffset, color: h.color,
      };
      // The highlighted words, kept so lists of highlights can show them without loading the chapter
      if (typeof h.text === 'string' && h.text.length > 0) entry.text = h.text.slice(0, 500);
      // Which translation the words were selected in, and whether it is a whole-verse highlight
      if (typeof h.translation === 'string' && /^[A-Za-z0-9]{2,8}$/.test(h.translation)) entry.translation = h.translation;
      if (h.whole === true) entry.whole = true;
      if (typeof h.note === 'string' && h.note.trim()) entry.note = h.note.slice(0, MAX_NOTE);
      highlights.push(entry);
    }
  }
  return { bookmarks, highlights, bookmarkNotes };
}