'use strict';

const SQLITE_BUSY_RETRY_DELAYS_MS = [
  25,
  50,
  100,
  200,
  400,
  800,
  1600,
];

function sleep(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}

function isSqliteBusy(error) {
  if (!error) return false;

  if (
    error.code === 'SQLITE_BUSY' ||
    error.code === 'SQLITE_LOCKED'
  ) {
    return true;
  }

  const message = String(
    error.message || error
  ).toLowerCase();

  return (
    message.includes('database is locked') ||
    message.includes('database table is locked')
  );
}

async function withSqliteBusyRetry(label, operation) {
  let retry = 0;

  while (true) {
    try {
      return await operation();
    } catch (error) {
      if (
        !isSqliteBusy(error) ||
        retry >= SQLITE_BUSY_RETRY_DELAYS_MS.length
      ) {
        throw error;
      }

      const delay = SQLITE_BUSY_RETRY_DELAYS_MS[retry];
      retry += 1;

      console.warn(
        `[SQLiteRetry] SQLITE_BUSY ${label}; ` +
        `retry=${retry}/${SQLITE_BUSY_RETRY_DELAYS_MS.length} ` +
        `delay=${delay}ms`
      );

      await sleep(delay);
    }
  }
}

module.exports = {
  isSqliteBusy,
  withSqliteBusyRetry,
};