/**
 * ─────────────────────────────────────────────
 *  SPB Drive — Personal Cloud Drive
 * ─────────────────────────────────────────────
 *  Author  : Simon-Pierre Boucher
 *  Contact : contact@spboucher.ai
 *  File    : src/search/search.mjs
 *  Purpose : FTS5 queries with filters (type, tag, folder, dates, size, starred)
 *  License : MIT © Simon-Pierre Boucher
 * ─────────────────────────────────────────────
 */

import { getDb } from '../db/db.mjs';

const TYPE_BUCKETS = {
  image: "n.mime LIKE 'image/%'",
  video: "n.mime LIKE 'video/%'",
  audio: "n.mime LIKE 'audio/%'",
  doc: "(n.mime = 'application/pdf' OR n.mime LIKE 'text/%' OR n.mime LIKE '%word%' OR n.mime LIKE '%sheet%' OR n.mime LIKE '%presentation%' OR n.mime LIKE '%opendocument%')",
  archive: "(n.mime LIKE '%zip%' OR n.mime LIKE '%tar%' OR n.mime LIKE '%7z%' OR n.mime LIKE '%rar%' OR n.mime LIKE '%gzip%')",
  folder: "n.type = 'folder'",
};

/** Escape user input for an FTS5 MATCH — quote each term, keep prefix `*`. */
function ftsQuery(q) {
  const terms = String(q).trim().split(/\s+/).filter(Boolean).slice(0, 12);
  if (terms.length === 0) return null;
  return terms
    .map((t) => {
      const prefix = t.endsWith('*');
      const clean = t.replace(/["']/g, '');
      if (!clean) return null;
      return `"${clean.replace(/\*/g, '')}"${prefix ? '*' : ''}`;
    })
    .filter(Boolean)
    .join(' ');
}

/**
 * Full-text search over names, tags and extracted content.
 * @param {string} q
 * @param {{type?: string, tag?: string, folderId?: number, starred?: boolean,
 *          shared?: boolean, after?: number, before?: number,
 *          minSize?: number, maxSize?: number, limit?: number}} filters
 * @returns {Array<object>} node rows + snippet
 */
export function searchNodes(q, filters = {}) {
  const db = getDb();
  const match = ftsQuery(q);
  if (!match) return [];

  const where = ['n.trashed_at IS NULL'];
  const params = { match, limit: Math.min(filters.limit ?? 100, 500) };

  if (filters.type && TYPE_BUCKETS[filters.type]) where.push(TYPE_BUCKETS[filters.type]);
  if (filters.starred) where.push('n.starred = 1');
  if (filters.after) { where.push('n.modified >= @after'); params.after = filters.after; }
  if (filters.before) { where.push('n.modified <= @before'); params.before = filters.before; }
  if (filters.minSize) { where.push('n.size >= @minSize'); params.minSize = filters.minSize; }
  if (filters.maxSize) { where.push('n.size <= @maxSize'); params.maxSize = filters.maxSize; }
  if (filters.tag) {
    where.push('EXISTS (SELECT 1 FROM node_tags nt JOIN tags t ON t.id = nt.tag_id WHERE nt.node_id = n.id AND t.name = @tag)');
    params.tag = filters.tag;
  }
  if (filters.shared) {
    where.push('EXISTS (SELECT 1 FROM shares s WHERE s.node_id = n.id AND s.revoked_at IS NULL)');
  }

  let rows = db
    .prepare(
      `SELECT n.*, snippet(fts, 2, '<mark>', '</mark>', ' … ', 12) AS snippet,
              bm25(fts, 8.0, 4.0, 1.0) AS rank
       FROM fts JOIN nodes n ON n.id = fts.rowid
       WHERE fts MATCH @match AND ${where.join(' AND ')}
       ORDER BY rank LIMIT @limit`,
    )
    .all(params);

  // Folder-scope filter walks ancestry in JS (cheap at these result sizes).
  if (filters.folderId) {
    const inScope = (id) => {
      let cur = db.prepare('SELECT id, parent_id FROM nodes WHERE id = ?').get(id);
      while (cur) {
        if (cur.id === Number(filters.folderId)) return true;
        cur = cur.parent_id
          ? db.prepare('SELECT id, parent_id FROM nodes WHERE id = ?').get(cur.parent_id)
          : null;
      }
      return false;
    };
    rows = rows.filter((r) => inScope(r.id));
  }
  return rows;
}

/** Optimize the FTS index (daily maintenance). */
export function vacuumFts() {
  getDb().prepare("INSERT INTO fts(fts) VALUES ('optimize')").run();
}