patrickarlt/acetate

const chalk = require("chalk");
const util = require("util");
const EventEmitter = require("events");
const uuid = require("node-uuid").v4;
const prettyHrtime = require("pretty-hrtime");

const LEVELS = {
  debug: 1,
  info: 2,
  success: 2,
  warn: 3,
  error: 3
};

const COLORS = {
  debug: chalk.dim,
  info: string => string,
  success: chalk.green,
  warn: chalk.yellow,
  error: chalk.red
};

module.exports = class Logger extends EventEmitter {
  constructor({ level = "info" } = {}) {
    super();
    this._prefix = "[" + chalk.blue("Acetate") + "]";
    this._timers = {};
    this._level = LEVELS[level] || Infinity;
  }

  time(label) {
    label = label || uuid();
    this._timers[label] = process.hrtime();
    return label;
  }

  timeEnd(label) {
    const end = process.hrtime(this._timers[label]);
    delete this._timers[label];
    return prettyHrtime(end);
  }

  log(level, message, ...rest) {
    const color = COLORS[level];
    const args = [this._prefix + " " + color(message)].concat(rest);
    const text = util.format.apply({}, args);
    const print = this._level <= LEVELS[level];

    this.emit("log", {
      show: print,
      level: level,
      text: util.format.apply({}, [message].concat(rest))
    });

    if (print) {
      process.stdout.write(text + "\n");
    }

    return text;
  }

  debug(message, ...rest) {
    return this.log("debug", message, ...rest);
  }

  info(message, ...rest) {
    return this.log("info", message, ...rest);
  }

  success(message, ...rest) {
    return this.log("success", message, ...rest);
  }

  warn(message, ...rest) {
    return this.log("warn", message, ...rest);
  }

  error(message, ...rest) {
    return this.log("error", message, ...rest);
  }
};