const moment = require('moment');
const path = require('path');
const _ = require('lodash');

const settings = require('../data/settings.json');

const LOWERS = settings.titlecase.lowers;
const UPPERS = settings.titlecase.uppers;
const CWD = process.cwd(); // get the current working directory
const LOG_LEVEL = 'low'; // should we print more information when log printing ['debug','high','medium','low']


/**
 * get a stack error and get the details we need for logging
 *
 * @param {Object} stack Error stack.
 *
 * @return {Object} just the stuff we need for logging details;
 */
const getStackInfo = stack => {
  let whodidit = stack
    .split('\n')[2]
    .trim()
    .substring(3)
    .replace(/\s\(/, ' at ')
    .replace(/\)/, ''); // strip out the stuff we dont care about
  let [caller, fileinfo] = whodidit.split(' at '); // grab the caller and fileinfo
  let [filename, linenumber, columnnumber] = fileinfo ? fileinfo.split(':', 3) : ['', '', '']; // get the filename line number and column number
  let relative = path.relative(CWD, filename); // get the relative path
  let name = `dc:${relative}`.replace(/.js$/, ''); // get a clean relative path name
  return {
    // return what we care about
    filename: filename,
    linenumber: linenumber,
    columnnumber: columnnumber,
    caller: caller,
    name: name,
  };
};

/**
 * get the name from the module
 *
 * @param {Object} mod module that is requireing us.
 *
 * @return {Object} just the stuff we need for logging details;
 */
const getNameFromModule = mod => {
  let filename = mod && mod.parent && mod.parent.filename ? mod.parent.filename : ''; // who included me?
  let relative = path.relative(CWD, filename); // get the relative path
  let name = `dc:${relative}`.replace(/.js$/, ''); // get a clean relative path name
  return {
    // return what we care about
    name: name,
  };
};

/**
 * is a value blank?
 *
 * @param {Object} value value to check.
 *
 * @return {Boolean} result of the test.
 */
const isBlank = value => {
  return (_.isEmpty(value) && !_.isNumber(value)) || _.isNaN(value);
};

/**
 * log
 *
 * @param {String} str string to print.
 * @param {Boolean} clearLine clear the line?.
 */
const log = (...args) => {
  let { name, linenumber, columnnumber, caller } = getStackInfo(new Error().stack);
  let debug = require('debug')(name); // require debug
  let logArgs = args.slice(0); // clone args
  if (LOG_LEVEL && LOG_LEVEL === 'debug') {
    // only add stuff if we want it ... IE debug
    logArgs.unshift(`${linenumber}:${columnnumber}`); // add the linenumber and columnnumber
    logArgs.unshift(`${caller}`); // add the name
  }
  if (LOG_LEVEL && ['debug', 'high', 'medium'].indexOf(LOG_LEVEL) > -1) {
    logArgs.unshift(`${name} :`); // add the name
    logArgs.unshift(`${now()} -`); // add the timestamp
  }
  debug.apply(this, args);
  return console.log.apply(this, logArgs); // apply the new console.log
};

/**
 * print line
 *
 * @param {String} str string to print.
 * @param {Boolean} clearLine clear the line?.
 */
const println = (str = '', clearLine = true) => {
  if (clearLine) {
    process.stdout.clearLine();
    process.stdout.cursorTo(0);
  }
  process.stdout.write(str);
};

/**
 * use moment to get a string version of now
 *
 * @param {Date|String|Number} seed seed the moment.
 *
 * @return {String} now formatted with DATE_TIME_FORMAT;
 */
const now = seed => {
  // private now ... so we can use it locally
  let n = seed ? moment(seed) : moment();
  return n.toISOString();
};


/**
 * string to title case
 *
 * @param {String} str string to print.
 */
const toTitleCase = (str = '') => {
  str = str.replace(/([^\W_]+[^\s-]*) */g, txt => txt.charAt(0).toUpperCase() + txt.substr(1).toLowerCase());
  for (let i = 0, j = LOWERS.length; i < j; i++) str = str.replace(new RegExp('\\s' + LOWERS[i] + '\\s', 'g'), txt => txt.toLowerCase());
  for (let i = 0, j = UPPERS.length; i < j; i++) str = str.replace(new RegExp('\\b' + UPPERS[i] + '\\b', 'g'), UPPERS[i].toUpperCase());
  return str;
};

module.exports = {

  _,

  after: (...args) => {
    return moment()
      .add(...args)
      .format(DATE_TIME_FORMAT);
  },

  before: (...args) => {
    return moment()
      .subtract(...args)
      .format(DATE_TIME_FORMAT);
  },

  debug: (...args) => {
    let { name } = getStackInfo(new Error().stack);
    let debug = require('debug')(name); // require debug
    if (LOG_LEVEL && LOG_LEVEL === 'debug') {
      let logArgs = args.slice(0); // clone args
      logArgs.unshift(`${name} :`); // add the name
      logArgs.unshift(`${now()} -`); // add the timestamp
      console.log.apply(this, logArgs); // apply the new console.log
    }
    return debug.apply(this, args); // send the orig args to debug
  },

  errorpromise: (...args) => {
    return Promise.reject(new Error(args));
  },

  isArray: v => {
    return _.isArray(v); // use lodash is array check
  },

  isBlank,

  isEmpty: v => {
    return _.isEmpty(v); // use lodash is empty check
  },

  isJson: v => {
    // safe check if this is json
    v = typeof v !== 'string' ? JSON.stringify(v) : v;
    try {
      v = JSON.parse(v);
    } catch (e) {
      return false;
    }
    return v && typeof v === 'object' && v !== null ? true : false;
  },

  later: (...args) => {
    return moment()
      .add(...args)
      .format(DATE_TIME_FORMAT);
  },


  log,

  moment: seed => {
    return seed ? moment(seed) : moment(); // return a new moment object ...
  },

  now, // alias the private method

  println,

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

  toJson: v => {
    try {
      v = v && typeof v === 'string' ? JSON.parse(v) : v;
    } catch (e) {
      console.error('toJson error', e.message || e);
      return false;
    }
    return v;
  },

  toTitleCase

};