import chalk from 'chalk';

/**
 * Formats the given date for logging
 * @param {Date} date the date to format
 * @returns {string} the formatted date string in yyyy/mm/dd hh/mm/ss/SSS
 */
export const time = (date) => {
  /**
   * Stringifies the given number, prepends with 0s if the number string isn't long enough
   * @param {number} num the number to stringify
   * @param {number} expectedLength how long the number should be
   * @returns {string} the stringified number
   */
  const stringifyNumber = (num, expectedLength) => {
    let str = `${num}`;
    while (str.length < expectedLength) {
      str = `0${str}`;
    }
    return str;
  };

  const year = date.getFullYear()
  const month = stringifyNumber(date.getMonth(), 2);
  const day = stringifyNumber(date.getDay(), 2);
  const hour = stringifyNumber(date.getHours(), 2);
  const minute = stringifyNumber(date.getMinutes(), 2);
  const second = stringifyNumber(date.getSeconds(), 2);
  const millisecond = stringifyNumber(date.getMilliseconds(), 2);

  return `${year}/${month}/${day} ${hour}:${minute}:${second}.${millisecond}`;
}

/**
 * Logs a message to the console
 * @param {string} message the message to log
 * @param {'debug'|'info'|'log'|'warn'|'error'} kind the kind of message being logged; denotes logging level
 * - debug is lowest level of message (0)
 * - info is the second lowest level of message (1)
 * - log is the default level level of message (2)
 * - warn is the second highest level of message (3)
 * - error is the highest level of message (4)
 * @param {string} context the context; if undefined, assume part of a parent context and indent the message
 * @param {string} extraData any extra data (e.g. if there was an error, pass the error object here)
 */
export const log = (message, kind, context, extraData) => {
  const logLevel = process.env.npm_config_logging || 2;
  const formatted = `${chalk.bold(`[${time(new Date())}] `)}${context ? context + ': ' : '  '}${message}`;
  switch (kind) {
    case 'debug': {
      if (logLevel > 0) {
        return;
      }
      if (extraData) {
        console.debug(`${chalk.gray.bold('[debug]')}${formatted}`, extraData);
      } else {
        console.debug(`${chalk.gray.bold('[debug]')}${formatted}`);
      }
      break;
    }
    case 'info': {
      if (logLevel > 1) {
        return;
      }
      if (extraData) {
        console.info(`${chalk.white.bold('[info]')}${formatted}`, extraData);
      } else {
        console.info(`${chalk.white.bold('[info]')}${formatted}`);
      }
      break;
    }
    case 'warn': {
      if (logLevel > 3) {
        return;
      }
      if (extraData) {
        console.warn(`${chalk.yellow.bold('[warn]')}${formatted}`, extraData);
      } else {
        console.warn(`${chalk.yellow.bold('[warn]')}${formatted}`);
      }
      break;
    }
    case 'error': {
      if (extraData) {
        console.error(`${chalk.red.bold('[error]')}${formatted}`, extraData);
      } else {
        console.error(`${chalk.red.bold('[error]')}${formatted}`);
      }
      break;
    }
    default: {
      if (logLevel > 2) {
        return;
      }
      if (extraData) {
        console.log(`${chalk.blue.bold('[log]')}${formatted}`, extraData);
      } else {
        console.log(`${chalk.blue.bold('[log]')}${formatted}`);
      }
      break;
    }
  }
};