bitwig-nks-preview-generator/lib/logger.js

Streaming convert NKSF files to preview audio with using Bitwig Studio.

const chalk = require('chalk'),
      timestamp = require('time-stamp'),
      eol = require('os').EOL

/**
 * default style
 */
const defaultStyle = {
  timestamp: chalk.gray,
  level: chalk.black.bgWhite,
  category: chalk.gray
}

/**
 * default styles for each log level
 */
const defaultStyles = {
  debug: Object.assign({}, defaultStyle, {
    level: chalk.black.bgCyan
  }),
  info: Object.assign({}, defaultStyle, {
    level: chalk.black.bgGreenBright
  }),
  error: Object.assign({}, defaultStyle, {
    level: chalk.white.bgRedBright
  })
}

/**
 * A simpple logger class
 * @class
 */
class Logger {
  constructor(categories) {
    this.categories = Array.isArray(categories)
      ? categories : typeof categories === 'undefined'
        ? [] : [categories]
  }

  /**
   * Configure logger
   * @static
   * @method
   * @param {Number} level - log verbose level
   *  - 0 no output
   *  - 1 ERROR
   *  - 2 ERROR, INFO
   *  - 3 ERROR, INFO, DEBUG
   * @param {WriteStream} out - output stream, default: process.stdout
   * @param {Object} style
   */
  static configure(level, out = process.stdout, styles = defaultStyles) {
    this.level = level
    this.out = out
    this.styles = styles
  }

  /**
   * Output debug message
   * @method
   */
  debug() {
    if (!Logger.out || Logger.level < 3) return
    this._header('DEBUG', Logger.styles.debug)
    if (Logger.out === process.stdout) {
      console.log.apply(console, arguments)
    } else if (Logger.out === process.stderr) {
      console.error.apply(console, arguments)
    } else {
      arguments.forEach(Logger.out.write)
      Logger.out.write(eol)
    }
  }

  /**
   * Output info message
   * @method
   */
  info() {
    if (!Logger.out || Logger.level < 2) return
    this._header('INFO ', Logger.styles.info)
    if (Logger.out === process.stdout) {
      console.log.apply(console, arguments)
    } else if (Logger.out === process.stderr) {
      console.error.apply(console, arguments)
    } else {
      arguments.forEach(Logger.out.write)
      Logger.out.write(eol)
    }
  }

  /**
   * Output error message
   * @method
   */
  error() {
    if (!Logger.out || Logger.level < 1) return
    this._header('ERROR', Logger.styles.error)
    if (Logger.out === process.stdout) {
      console.log.apply(console, arguments)
    } else if (Logger.out === process.stderr) {
      console.error.apply(console, arguments)
    } else {
      arguments.forEach(Logger.out.write)
      Logger.out.write(eol)
    }
  }

  _header(level, style) {
    Logger.out.write(style.timestamp(getTimestamp()) + ' ')
    Logger.out.write(style.level(level) + ' ')
    this.categories.map(e => {
      return style.category(`[${e}]`) + ' '
    }).forEach(e => Logger.out.write(e))
  }
}

function getTimestamp() {
  return timestamp('HH:mm:ss.ms')
}

function logger() {
  return new Logger(Array.prototype.slice.call(arguments))
}

logger.configure = function(level, out, styles) {
  Logger.configure(level, out, styles)
}

module.exports = logger