const LOG_LEVEL = (typeof process !== 'undefined' && process.env && process.env.LOG_LEVEL) || 'silent';

const LEVELS = {
  silent: -1, error: 0, warn: 1, info: 2, verbose: 3, debug: 4, silly: 5,
};

const cache = {};

function build(level = LOG_LEVEL, prefix = '') {
  const threshold = LEVELS[level] != null ? LEVELS[level] : LEVELS.silent;
  const noop = () => {};
  // Preserve printf-style interpolation (%s/%d/%o/...): when there is a
  // prefix and the first argument is the format string, merge the prefix
  // into it. Otherwise hand the prefix to console.* as a leading argument.
  const fmt = prefix
    ? (...a) => {
      if (a.length === 0) return [prefix];
      const [first, ...rest] = a;
      return typeof first === 'string' ? [`${prefix} ${first}`, ...rest] : [prefix, first, ...rest];
    }
    : (...a) => a;

  const logger = {
    error: threshold >= 0 ? (...a) => console.error(...fmt(...a)) : noop,
    warn: threshold >= 1 ? (...a) => console.warn(...fmt(...a)) : noop,
    info: threshold >= 2 ? (...a) => console.info(...fmt(...a)) : noop,
    verbose: threshold >= 3 ? (...a) => console.debug(...fmt(...a)) : noop,
    debug: threshold >= 4 ? (...a) => console.debug(...fmt(...a)) : noop,
    silly: threshold >= 5 ? (...a) => console.debug(...fmt(...a)) : noop,
    getForId(id, overrideLevel) {
      const effective = overrideLevel || level;
      const key = `${id}\0${effective}`;
      if (!cache[key]) {
        cache[key] = build(effective, `[DAPIClient: ${id}]`);
      }
      return cache[key];
    },
  };
  return logger;
}

module.exports = build();