import { pool } from '../../config/db.js';

// Notas propias MAS las compartidas conmigo. is_owner permite al frontend decidir si se puede
// editar/borrar/compartir/arrastrar (siempre false para una nota compartida: el dueno nunca
// cambia, y el orden manual de otro usuario no tiene sentido para mi vista). Propias primero (en
// su orden manual), compartidas despues (por fecha -- nunca arrastrables).
export async function findVisibleToUser(userId) {
  const [rows] = await pool.query(
    `SELECT n.id, n.user_id, n.content, n.created_at, n.updated_at,
            (n.user_id = ?) AS is_owner, u.name AS owner_name,
            (SELECT COUNT(*) FROM note_shares ns WHERE ns.note_id = n.id) AS share_count
     FROM notes n
     JOIN users u ON u.id = n.user_id
     WHERE n.user_id = ? OR n.id IN (SELECT note_id FROM note_shares WHERE user_id = ?)
     ORDER BY is_owner DESC, CASE WHEN is_owner THEN n.sort_order ELSE 0 END DESC, n.updated_at DESC`,
    [userId, userId, userId]
  );
  return rows.map((r) => ({ ...r, is_owner: !!r.is_owner, share_count: Number(r.share_count) }));
}

// Posiciones SIEMPRE N..1 (nunca 0 -- ver migracion 020). El primer id del arreglo (arriba del
// todo visualmente) recibe el numero MAS ALTO porque el ORDER BY de arriba es DESC. Solo toca
// notas propias de userId, ignora cualquier id ajeno que venga en la lista.
export async function reorder(userId, ids) {
  const total = ids.length;
  for (let i = 0; i < total; i++) {
    await pool.query('UPDATE notes SET sort_order = ? WHERE id = ? AND user_id = ?', [total - i, ids[i], userId]);
  }
}

export async function findById(id) {
  const [rows] = await pool.query('SELECT id, user_id, content, created_at, updated_at FROM notes WHERE id = ?', [id]);
  return rows[0] || null;
}

export async function create(userId, content) {
  const [result] = await pool.query('INSERT INTO notes (user_id, content) VALUES (?, ?)', [userId, content]);
  return findById(result.insertId);
}

export async function update(id, content) {
  await pool.query('UPDATE notes SET content = ? WHERE id = ?', [content, id]);
  return findById(id);
}

export async function remove(id) {
  await pool.query('DELETE FROM notes WHERE id = ?', [id]);
}

export async function listShares(noteId) {
  const [rows] = await pool.query(
    `SELECT ns.user_id, u.name, u.email, ns.shared_at
     FROM note_shares ns JOIN users u ON u.id = ns.user_id
     WHERE ns.note_id = ? ORDER BY u.name`,
    [noteId]
  );
  return rows;
}

export async function isSharedWith(noteId, userId) {
  const [rows] = await pool.query('SELECT 1 FROM note_shares WHERE note_id = ? AND user_id = ?', [noteId, userId]);
  return rows.length > 0;
}

export async function addShare(noteId, userId) {
  await pool.query('INSERT IGNORE INTO note_shares (note_id, user_id) VALUES (?, ?)', [noteId, userId]);
  return listShares(noteId);
}

export async function removeShare(noteId, userId) {
  await pool.query('DELETE FROM note_shares WHERE note_id = ? AND user_id = ?', [noteId, userId]);
  return listShares(noteId);
}