'use strict' const argsert = require('./lib/argsert') const fs = require('fs') const Command = require('./lib/command') const Completion = require('./lib/completion') const Parser = require('yargs-parser') const path = require('path') const Usage = require('./lib/usage') const Validation = require('./lib/validation') const Y18n = require('y18n') const objFilter = require('./lib/obj-filter') const setBlocking = require('set-blocking') const applyExtends = require('./lib/apply-extends') const { globalMiddlewareFactory } = require('./lib/middleware') const YError = require('./lib/yerror')

exports = module.exports = Yargs function Yargs (processArgs, cwd, parentRequire) {

processArgs = processArgs || [] // handle calling yargs().

const self = {}
let command = null
let completion = null
let groups = {}
let globalMiddleware = []
let output = ''
let preservedGroups = {}
let usage = null
let validation = null

const y18n = Y18n({
  directory: path.resolve(__dirname, './locales'),
  updateFiles: false
})

self.middleware = globalMiddlewareFactory(globalMiddleware, self)

if (!cwd) cwd = process.cwd()

self.scriptName = function scriptName (scriptName) {
  self.$0 = scriptName
  return self
}

// ignore the node bin, specify this in your
// bin file with #!/usr/bin/env node
if (/\b(node|iojs|electron)(\.exe)?$/.test(process.argv[0])) {
  self.$0 = process.argv.slice(1, 2)
} else {
  self.$0 = process.argv.slice(0, 1)
}

self.$0 = self.$0
  .map((x, i) => {
    const b = rebase(cwd, x)
    return x.match(/^(\/|([a-zA-Z]:)?\\)/) && b.length < x.length ? b : x
  })
  .join(' ').trim()

if (process.env._ !== undefined && process.argv[1] === process.env._) {
  self.$0 = process.env._.replace(
    `${path.dirname(process.execPath)}/`, ''
  )
}

// use context object to keep track of resets, subcommand execution, etc
// submodules should modify and check the state of context as necessary
const context = { resets: -1, commands: [], fullCommands: [], files: [] }
self.getContext = () => context

// puts yargs back into an initial state. any keys
// that have been set to "global" will not be reset
// by this action.
let options
self.resetOptions = self.reset = function resetOptions (aliases) {
  context.resets++
  aliases = aliases || {}
  options = options || {}
  // put yargs back into an initial state, this
  // logic is used to build a nested command
  // hierarchy.
  const tmpOptions = {}
  tmpOptions.local = options.local ? options.local : []
  tmpOptions.configObjects = options.configObjects ? options.configObjects : []

  // if a key has been explicitly set as local,
  // we should reset it before passing options to command.
  const localLookup = {}
  tmpOptions.local.forEach((l) => {
    localLookup[l] = true
    ;(aliases[l] || []).forEach((a) => {
      localLookup[a] = true
    })
  })

  // preserve all groups not set to local.
  preservedGroups = Object.keys(groups).reduce((acc, groupName) => {
    const keys = groups[groupName].filter(key => !(key in localLookup))
    if (keys.length > 0) {
      acc[groupName] = keys
    }
    return acc
  }, {})
  // groups can now be reset
  groups = {}

  const arrayOptions = [
    'array', 'boolean', 'string', 'skipValidation',
    'count', 'normalize', 'number',
    'hiddenOptions'
  ]

  const objectOptions = [
    'narg', 'key', 'alias', 'default', 'defaultDescription',
    'config', 'choices', 'demandedOptions', 'demandedCommands', 'coerce'
  ]

  arrayOptions.forEach((k) => {
    tmpOptions[k] = (options[k] || []).filter(k => !localLookup[k])
  })

  objectOptions.forEach((k) => {
    tmpOptions[k] = objFilter(options[k], (k, v) => !localLookup[k])
  })

  tmpOptions.envPrefix = options.envPrefix
  options = tmpOptions

  // if this is the first time being executed, create
  // instances of all our helpers -- otherwise just reset.
  usage = usage ? usage.reset(localLookup) : Usage(self, y18n)
  validation = validation ? validation.reset(localLookup) : Validation(self, usage, y18n)
  command = command ? command.reset() : Command(self, usage, validation, globalMiddleware)
  if (!completion) completion = Completion(self, usage, command)

  completionCommand = null
  output = ''
  exitError = null
  hasOutput = false
  self.parsed = false

  return self
}
self.resetOptions()

// temporary hack: allow "freezing" of reset-able state for parse(msg, cb)
let frozen
function freeze () {
  frozen = {}
  frozen.options = options
  frozen.configObjects = options.configObjects.slice(0)
  frozen.exitProcess = exitProcess
  frozen.groups = groups
  usage.freeze()
  validation.freeze()
  command.freeze()
  frozen.strict = strict
  frozen.completionCommand = completionCommand
  frozen.output = output
  frozen.exitError = exitError
  frozen.hasOutput = hasOutput
  frozen.parsed = self.parsed
}
function unfreeze () {
  options = frozen.options
  options.configObjects = frozen.configObjects
  exitProcess = frozen.exitProcess
  groups = frozen.groups
  output = frozen.output
  exitError = frozen.exitError
  hasOutput = frozen.hasOutput
  self.parsed = frozen.parsed
  usage.unfreeze()
  validation.unfreeze()
  command.unfreeze()
  strict = frozen.strict
  completionCommand = frozen.completionCommand
  parseFn = null
  parseContext = null
  frozen = undefined
}

self.boolean = function (keys) {
  argsert('<array|string>', [keys], arguments.length)
  populateParserHintArray('boolean', keys)
  return self
}

self.array = function (keys) {
  argsert('<array|string>', [keys], arguments.length)
  populateParserHintArray('array', keys)
  return self
}

self.number = function (keys) {
  argsert('<array|string>', [keys], arguments.length)
  populateParserHintArray('number', keys)
  return self
}

self.normalize = function (keys) {
  argsert('<array|string>', [keys], arguments.length)
  populateParserHintArray('normalize', keys)
  return self
}

self.count = function (keys) {
  argsert('<array|string>', [keys], arguments.length)
  populateParserHintArray('count', keys)
  return self
}

self.string = function (keys) {
  argsert('<array|string>', [keys], arguments.length)
  populateParserHintArray('string', keys)
  return self
}

self.requiresArg = function (keys) {
  argsert('<array|string>', [keys], arguments.length)
  populateParserHintObject(self.nargs, false, 'narg', keys, 1)
  return self
}

self.skipValidation = function (keys) {
  argsert('<array|string>', [keys], arguments.length)
  populateParserHintArray('skipValidation', keys)
  return self
}

function populateParserHintArray (type, keys, value) {
  keys = [].concat(keys)
  keys.forEach((key) => {
    options[type].push(key)
  })
}

self.nargs = function (key, value) {
  argsert('<string|object|array> [number]', [key, value], arguments.length)
  populateParserHintObject(self.nargs, false, 'narg', key, value)
  return self
}

self.choices = function (key, value) {
  argsert('<object|string|array> [string|array]', [key, value], arguments.length)
  populateParserHintObject(self.choices, true, 'choices', key, value)
  return self
}

self.alias = function (key, value) {
  argsert('<object|string|array> [string|array]', [key, value], arguments.length)
  populateParserHintObject(self.alias, true, 'alias', key, value)
  return self
}

// TODO: actually deprecate self.defaults.
self.default = self.defaults = function (key, value, defaultDescription) {
  argsert('<object|string|array> [*] [string]', [key, value, defaultDescription], arguments.length)
  if (defaultDescription) options.defaultDescription[key] = defaultDescription
  if (typeof value === 'function') {
    if (!options.defaultDescription[key]) options.defaultDescription[key] = usage.functionDescription(value)
    value = value.call()
  }
  populateParserHintObject(self.default, false, 'default', key, value)
  return self
}

self.describe = function (key, desc) {
  argsert('<object|string|array> [string]', [key, desc], arguments.length)
  populateParserHintObject(self.describe, false, 'key', key, true)
  usage.describe(key, desc)
  return self
}

self.demandOption = function (keys, msg) {
  argsert('<object|string|array> [string]', [keys, msg], arguments.length)
  populateParserHintObject(self.demandOption, false, 'demandedOptions', keys, msg)
  return self
}

self.coerce = function (keys, value) {
  argsert('<object|string|array> [function]', [keys, value], arguments.length)
  populateParserHintObject(self.coerce, false, 'coerce', keys, value)
  return self
}

function populateParserHintObject (builder, isArray, type, key, value) {
  if (Array.isArray(key)) {
    // an array of keys with one value ['x', 'y', 'z'], function parse () {}
    const temp = {}
    key.forEach((k) => {
      temp[k] = value
    })
    builder(temp)
  } else if (typeof key === 'object') {
    // an object of key value pairs: {'x': parse () {}, 'y': parse() {}}
    Object.keys(key).forEach((k) => {
      builder(k, key[k])
    })
  } else {
    // a single key value pair 'x', parse() {}
    if (isArray) {
      options[type][key] = (options[type][key] || []).concat(value)
    } else {
      options[type][key] = value
    }
  }
}

function deleteFromParserHintObject (optionKey) {
  // delete from all parsing hints:
  // boolean, array, key, alias, etc.
  Object.keys(options).forEach((hintKey) => {
    const hint = options[hintKey]
    if (Array.isArray(hint)) {
      if (~hint.indexOf(optionKey)) hint.splice(hint.indexOf(optionKey), 1)
    } else if (typeof hint === 'object') {
      delete hint[optionKey]
    }
  })
  // now delete the description from usage.js.
  delete usage.getDescriptions()[optionKey]
}

self.config = function config (key, msg, parseFn) {
  argsert('[object|string] [string|function] [function]', [key, msg, parseFn], arguments.length)
  // allow a config object to be provided directly.
  if (typeof key === 'object') {
    key = applyExtends(key, cwd)
    options.configObjects = (options.configObjects || []).concat(key)
    return self
  }

  // allow for a custom parsing function.
  if (typeof msg === 'function') {
    parseFn = msg
    msg = null
  }

  key = key || 'config'
  self.describe(key, msg || usage.deferY18nLookup('Path to JSON config file'))
  ;(Array.isArray(key) ? key : [key]).forEach((k) => {
    options.config[k] = parseFn || true
  })

  return self
}

self.example = function (cmd, description) {
  argsert('<string> [string]', [cmd, description], arguments.length)
  usage.example(cmd, description)
  return self
}

self.command = function (cmd, description, builder, handler, middlewares) {
  argsert('<string|array|object> [string|boolean] [function|object] [function] [array]', [cmd, description, builder, handler, middlewares], arguments.length)
  command.addHandler(cmd, description, builder, handler, middlewares)
  return self
}

self.commandDir = function (dir, opts) {
  argsert('<string> [object]', [dir, opts], arguments.length)
  const req = parentRequire || require
  command.addDirectory(dir, self.getContext(), req, require('get-caller-file')(), opts)
  return self
}

// TODO: deprecate self.demand in favor of
// .demandCommand() .demandOption().
self.demand = self.required = self.require = function demand (keys, max, msg) {
  // you can optionally provide a 'max' key,
  // which will raise an exception if too many '_'
  // options are provided.
  if (Array.isArray(max)) {
    max.forEach((key) => {
      self.demandOption(key, msg)
    })
    max = Infinity
  } else if (typeof max !== 'number') {
    msg = max
    max = Infinity
  }

  if (typeof keys === 'number') {
    self.demandCommand(keys, max, msg, msg)
  } else if (Array.isArray(keys)) {
    keys.forEach((key) => {
      self.demandOption(key, msg)
    })
  } else {
    if (typeof msg === 'string') {
      self.demandOption(keys, msg)
    } else if (msg === true || typeof msg === 'undefined') {
      self.demandOption(keys)
    }
  }

  return self
}

self.demandCommand = function demandCommand (min, max, minMsg, maxMsg) {
  argsert('[number] [number|string] [string|null|undefined] [string|null|undefined]', [min, max, minMsg, maxMsg], arguments.length)

  if (typeof min === 'undefined') min = 1

  if (typeof max !== 'number') {
    minMsg = max
    max = Infinity
  }

  self.global('_', false)

  options.demandedCommands._ = {
    min,
    max,
    minMsg,
    maxMsg
  }

  return self
}

self.getDemandedOptions = () => {
  argsert([], 0)
  return options.demandedOptions
}

self.getDemandedCommands = () => {
  argsert([], 0)
  return options.demandedCommands
}

self.implies = function (key, value) {
  argsert('<string|object> [number|string|array]', [key, value], arguments.length)
  validation.implies(key, value)
  return self
}

self.conflicts = function (key1, key2) {
  argsert('<string|object> [string|array]', [key1, key2], arguments.length)
  validation.conflicts(key1, key2)
  return self
}

self.usage = function (msg, description, builder, handler) {
  argsert('<string|null|undefined> [string|boolean] [function|object] [function]', [msg, description, builder, handler], arguments.length)

  if (description !== undefined) {
    // .usage() can be used as an alias for defining
    // a default command.
    if ((msg || '').match(/^\$0( |$)/)) {
      return self.command(msg, description, builder, handler)
    } else {
      throw new YError('.usage() description must start with $0 if being used as alias for .command()')
    }
  } else {
    usage.usage(msg)
    return self
  }
}

self.epilogue = self.epilog = function (msg) {
  argsert('<string>', [msg], arguments.length)
  usage.epilog(msg)
  return self
}

self.fail = function (f) {
  argsert('<function>', [f], arguments.length)
  usage.failFn(f)
  return self
}

self.check = function (f, _global) {
  argsert('<function> [boolean]', [f, _global], arguments.length)
  validation.check(f, _global !== false)
  return self
}

self.global = function global (globals, global) {
  argsert('<string|array> [boolean]', [globals, global], arguments.length)
  globals = [].concat(globals)
  if (global !== false) {
    options.local = options.local.filter(l => globals.indexOf(l) === -1)
  } else {
    globals.forEach((g) => {
      if (options.local.indexOf(g) === -1) options.local.push(g)
    })
  }
  return self
}

self.pkgConf = function pkgConf (key, rootPath) {
  argsert('<string> [string]', [key, rootPath], arguments.length)
  let conf = null
  // prefer cwd to require-main-filename in this method
  // since we're looking for e.g. "nyc" config in nyc consumer
  // rather than "yargs" config in nyc (where nyc is the main filename)
  const obj = pkgUp(rootPath || cwd)

  // If an object exists in the key, add it to options.configObjects
  if (obj[key] && typeof obj[key] === 'object') {
    conf = applyExtends(obj[key], rootPath || cwd)
    options.configObjects = (options.configObjects || []).concat(conf)
  }

  return self
}

const pkgs = {}
function pkgUp (rootPath) {
  const npath = rootPath || '*'
  if (pkgs[npath]) return pkgs[npath]
  const findUp = require('find-up')

  let obj = {}
  try {
    let startDir = rootPath || require('require-main-filename')(parentRequire || require)

    // When called in an environment that lacks require.main.filename, such as a jest test runner,
    // startDir is already process.cwd(), and should not be shortened.
    // Whether or not it is _actually_ a directory (e.g., extensionless bin) is irrelevant, find-up handles it.
    if (!rootPath && path.extname(startDir)) {
      startDir = path.dirname(startDir)
    }

    const pkgJsonPath = findUp.sync('package.json', {
      cwd: startDir
    })
    obj = JSON.parse(fs.readFileSync(pkgJsonPath))
  } catch (noop) {}

  pkgs[npath] = obj || {}
  return pkgs[npath]
}

let parseFn = null
let parseContext = null
self.parse = function parse (args, shortCircuit, _parseFn) {
  argsert('[string|array] [function|boolean|object] [function]', [args, shortCircuit, _parseFn], arguments.length)
  if (typeof args === 'undefined') {
    return self._parseArgs(processArgs)
  }

  // a context object can optionally be provided, this allows
  // additional information to be passed to a command handler.
  if (typeof shortCircuit === 'object') {
    parseContext = shortCircuit
    shortCircuit = _parseFn
  }

  // by providing a function as a second argument to
  // parse you can capture output that would otherwise
  // default to printing to stdout/stderr.
  if (typeof shortCircuit === 'function') {
    parseFn = shortCircuit
    shortCircuit = null
  }
  // completion short-circuits the parsing process,
  // skipping validation, etc.
  if (!shortCircuit) processArgs = args

  freeze()
  if (parseFn) exitProcess = false

  const parsed = self._parseArgs(args, shortCircuit)
  if (parseFn) parseFn(exitError, parsed, output)
  unfreeze()

  return parsed
}

self._getParseContext = () => parseContext || {}

self._hasParseCallback = () => !!parseFn

self.option = self.options = function option (key, opt) {
  argsert('<string|object> [object]', [key, opt], arguments.length)
  if (typeof key === 'object') {
    Object.keys(key).forEach((k) => {
      self.options(k, key[k])
    })
  } else {
    if (typeof opt !== 'object') {
      opt = {}
    }

    options.key[key] = true // track manually set keys.

    if (opt.alias) self.alias(key, opt.alias)

    const demand = opt.demand || opt.required || opt.require

    // deprecated, use 'demandOption' instead
    if (demand) {
      self.demand(key, demand)
    }

    if (opt.demandOption) {
      self.demandOption(key, typeof opt.demandOption === 'string' ? opt.demandOption : undefined)
    }

    if ('conflicts' in opt) {
      self.conflicts(key, opt.conflicts)
    }

    if ('default' in opt) {
      self.default(key, opt.default)
    }

    if ('implies' in opt) {
      self.implies(key, opt.implies)
    }

    if ('nargs' in opt) {
      self.nargs(key, opt.nargs)
    }

    if (opt.config) {
      self.config(key, opt.configParser)
    }

    if (opt.normalize) {
      self.normalize(key)
    }

    if ('choices' in opt) {
      self.choices(key, opt.choices)
    }

    if ('coerce' in opt) {
      self.coerce(key, opt.coerce)
    }

    if ('group' in opt) {
      self.group(key, opt.group)
    }

    if (opt.boolean || opt.type === 'boolean') {
      self.boolean(key)
      if (opt.alias) self.boolean(opt.alias)
    }

    if (opt.array || opt.type === 'array') {
      self.array(key)
      if (opt.alias) self.array(opt.alias)
    }

    if (opt.number || opt.type === 'number') {
      self.number(key)
      if (opt.alias) self.number(opt.alias)
    }

    if (opt.string || opt.type === 'string') {
      self.string(key)
      if (opt.alias) self.string(opt.alias)
    }

    if (opt.count || opt.type === 'count') {
      self.count(key)
    }

    if (typeof opt.global === 'boolean') {
      self.global(key, opt.global)
    }

    if (opt.defaultDescription) {
      options.defaultDescription[key] = opt.defaultDescription
    }

    if (opt.skipValidation) {
      self.skipValidation(key)
    }

    const desc = opt.describe || opt.description || opt.desc
    self.describe(key, desc)
    if (opt.hidden) {
      self.hide(key)
    }

    if (opt.requiresArg) {
      self.requiresArg(key)
    }
  }

  return self
}
self.getOptions = () => options

self.positional = function (key, opts) {
  argsert('<string> <object>', [key, opts], arguments.length)
  if (context.resets === 0) {
    throw new YError(".positional() can only be called in a command's builder function")
  }

  // .positional() only supports a subset of the configuration
  // options available to .option().
  const supportedOpts = ['default', 'defaultDescription', 'implies', 'normalize',
    'choices', 'conflicts', 'coerce', 'type', 'describe',
    'desc', 'description', 'alias']
  opts = objFilter(opts, (k, v) => {
    let accept = supportedOpts.indexOf(k) !== -1
    // type can be one of string|number|boolean.
    if (k === 'type' && ['string', 'number', 'boolean'].indexOf(v) === -1) accept = false
    return accept
  })

  // copy over any settings that can be inferred from the command string.
  const fullCommand = context.fullCommands[context.fullCommands.length - 1]
  const parseOptions = fullCommand ? command.cmdToParseOptions(fullCommand) : {
    array: [],
    alias: {},
    default: {},
    demand: {}
  }
  Object.keys(parseOptions).forEach((pk) => {
    if (Array.isArray(parseOptions[pk])) {
      if (parseOptions[pk].indexOf(key) !== -1) opts[pk] = true
    } else {
      if (parseOptions[pk][key] && !(pk in opts)) opts[pk] = parseOptions[pk][key]
    }
  })
  self.group(key, usage.getPositionalGroupName())
  return self.option(key, opts)
}

self.group = function group (opts, groupName) {
  argsert('<string|array> <string>', [opts, groupName], arguments.length)
  const existing = preservedGroups[groupName] || groups[groupName]
  if (preservedGroups[groupName]) {
    // we now only need to track this group name in groups.
    delete preservedGroups[groupName]
  }

  const seen = {}
  groups[groupName] = (existing || []).concat(opts).filter((key) => {
    if (seen[key]) return false
    return (seen[key] = true)
  })
  return self
}
// combine explicit and preserved groups. explicit groups should be first
self.getGroups = () => Object.assign({}, groups, preservedGroups)

// as long as options.envPrefix is not undefined,
// parser will apply env vars matching prefix to argv
self.env = function (prefix) {
  argsert('[string|boolean]', [prefix], arguments.length)
  if (prefix === false) options.envPrefix = undefined
  else options.envPrefix = prefix || ''
  return self
}

self.wrap = function (cols) {
  argsert('<number|null|undefined>', [cols], arguments.length)
  usage.wrap(cols)
  return self
}

let strict = false
self.strict = function (enabled) {
  argsert('[boolean]', [enabled], arguments.length)
  strict = enabled !== false
  return self
}
self.getStrict = () => strict

let parserConfig = {}
self.parserConfiguration = function parserConfiguration (config) {
  argsert('<object>', [config], arguments.length)
  parserConfig = config
  return self
}
self.getParserConfiguration = () => parserConfig

self.showHelp = function (level) {
  argsert('[string|function]', [level], arguments.length)
  if (!self.parsed) self._parseArgs(processArgs) // run parser, if it has not already been executed.
  if (command.hasDefaultCommand()) {
    context.resets++ // override the restriction on top-level positoinals.
    command.runDefaultBuilderOn(self, true)
  }
  usage.showHelp(level)
  return self
}

let versionOpt = null
self.version = function version (opt, msg, ver) {
  const defaultVersionOpt = 'version'
  argsert('[boolean|string] [string] [string]', [opt, msg, ver], arguments.length)

  // nuke the key previously configured
  // to return version #.
  if (versionOpt) {
    deleteFromParserHintObject(versionOpt)
    usage.version(undefined)
    versionOpt = null
  }

  if (arguments.length === 0) {
    ver = guessVersion()
    opt = defaultVersionOpt
  } else if (arguments.length === 1) {
    if (opt === false) { // disable default 'version' key.
      return self
    }
    ver = opt
    opt = defaultVersionOpt
  } else if (arguments.length === 2) {
    ver = msg
    msg = null
  }

  versionOpt = typeof opt === 'string' ? opt : defaultVersionOpt
  msg = msg || usage.deferY18nLookup('Show version number')

  usage.version(ver || undefined)
  self.boolean(versionOpt)
  self.describe(versionOpt, msg)
  return self
}

function guessVersion () {
  const obj = pkgUp()

  return obj.version || 'unknown'
}

let helpOpt = null
self.addHelpOpt = self.help = function addHelpOpt (opt, msg) {
  const defaultHelpOpt = 'help'
  argsert('[string|boolean] [string]', [opt, msg], arguments.length)

  // nuke the key previously configured
  // to return help.
  if (helpOpt) {
    deleteFromParserHintObject(helpOpt)
    helpOpt = null
  }

  if (arguments.length === 1) {
    if (opt === false) return self
  }

  // use arguments, fallback to defaults for opt and msg
  helpOpt = typeof opt === 'string' ? opt : defaultHelpOpt
  self.boolean(helpOpt)
  self.describe(helpOpt, msg || usage.deferY18nLookup('Show help'))
  return self
}

const defaultShowHiddenOpt = 'show-hidden'
options.showHiddenOpt = defaultShowHiddenOpt
self.addShowHiddenOpt = self.showHidden = function addShowHiddenOpt (opt, msg) {
  argsert('[string|boolean] [string]', [opt, msg], arguments.length)

  if (arguments.length === 1) {
    if (opt === false) return self
  }

  const showHiddenOpt = typeof opt === 'string' ? opt : defaultShowHiddenOpt
  self.boolean(showHiddenOpt)
  self.describe(showHiddenOpt, msg || usage.deferY18nLookup('Show hidden options'))
  options.showHiddenOpt = showHiddenOpt
  return self
}

self.hide = function hide (key) {
  argsert('<string|object>', [key], arguments.length)
  options.hiddenOptions.push(key)
  return self
}

self.showHelpOnFail = function showHelpOnFail (enabled, message) {
  argsert('[boolean|string] [string]', [enabled, message], arguments.length)
  usage.showHelpOnFail(enabled, message)
  return self
}

var exitProcess = true
self.exitProcess = function (enabled) {
  argsert('[boolean]', [enabled], arguments.length)
  if (typeof enabled !== 'boolean') {
    enabled = true
  }
  exitProcess = enabled
  return self
}
self.getExitProcess = () => exitProcess

var completionCommand = null
self.completion = function (cmd, desc, fn) {
  argsert('[string] [string|boolean|function] [function]', [cmd, desc, fn], arguments.length)

  // a function to execute when generating
  // completions can be provided as the second
  // or third argument to completion.
  if (typeof desc === 'function') {
    fn = desc
    desc = null
  }

  // register the completion command.
  completionCommand = cmd || 'completion'
  if (!desc && desc !== false) {
    desc = 'generate completion script'
  }
  self.command(completionCommand, desc)

  // a function can be provided
  if (fn) completion.registerFunction(fn)

  return self
}

self.showCompletionScript = function ($0) {
  argsert('[string]', [$0], arguments.length)
  $0 = $0 || self.$0
  _logger.log(completion.generateCompletionScript($0, completionCommand))
  return self
}

self.getCompletion = function (args, done) {
  argsert('<array> <function>', [args, done], arguments.length)
  completion.getCompletion(args, done)
}

self.locale = function (locale) {
  argsert('[string]', [locale], arguments.length)
  if (arguments.length === 0) {
    guessLocale()
    return y18n.getLocale()
  }
  detectLocale = false
  y18n.setLocale(locale)
  return self
}

self.updateStrings = self.updateLocale = function (obj) {
  argsert('<object>', [obj], arguments.length)
  detectLocale = false
  y18n.updateLocale(obj)
  return self
}

let detectLocale = true
self.detectLocale = function (detect) {
  argsert('<boolean>', [detect], arguments.length)
  detectLocale = detect
  return self
}
self.getDetectLocale = () => detectLocale

var hasOutput = false
var exitError = null
// maybe exit, always capture
// context about why we wanted to exit.
self.exit = (code, err) => {
  hasOutput = true
  exitError = err
  if (exitProcess) process.exit(code)
}

// we use a custom logger that buffers output,
// so that we can print to non-CLIs, e.g., chat-bots.
const _logger = {
  log () {
    const args = []
    for (let i = 0; i < arguments.length; i++) args.push(arguments[i])
    if (!self._hasParseCallback()) console.log.apply(console, args)
    hasOutput = true
    if (output.length) output += '\n'
    output += args.join(' ')
  },
  error () {
    const args = []
    for (let i = 0; i < arguments.length; i++) args.push(arguments[i])
    if (!self._hasParseCallback()) console.error.apply(console, args)
    hasOutput = true
    if (output.length) output += '\n'
    output += args.join(' ')
  }
}
self._getLoggerInstance = () => _logger
// has yargs output an error our help
// message in the current execution context.
self._hasOutput = () => hasOutput

self._setHasOutput = () => {
  hasOutput = true
}

let recommendCommands
self.recommendCommands = function (recommend) {
  argsert('[boolean]', [recommend], arguments.length)
  recommendCommands = typeof recommend === 'boolean' ? recommend : true
  return self
}

self.getUsageInstance = () => usage

self.getValidationInstance = () => validation

self.getCommandInstance = () => command

self.terminalWidth = () => {
  argsert([], 0)
  return typeof process.stdout.columns !== 'undefined' ? process.stdout.columns : null
}

Object.defineProperty(self, 'argv', {
  get: () => self._parseArgs(processArgs),
  enumerable: true
})

self._parseArgs = function parseArgs (args, shortCircuit, _skipValidation, commandIndex) {
  let skipValidation = !!_skipValidation
  args = args || processArgs

  options.__ = y18n.__
  options.configuration = self.getParserConfiguration()

  // Deprecated
  let pkgConfig = pkgUp()['yargs']
  if (pkgConfig) {
    console.warn('Configuring yargs through package.json is deprecated and will be removed in the next major release, please use the JS API instead.')
    options.configuration = Object.assign({}, pkgConfig, options.configuration)
  }

  const parsed = Parser.detailed(args, options)
  let argv = parsed.argv
  if (parseContext) argv = Object.assign({}, argv, parseContext)
  const aliases = parsed.aliases

  argv.$0 = self.$0
  self.parsed = parsed

  try {
    guessLocale() // guess locale lazily, so that it can be turned off in chain.

    // while building up the argv object, there
    // are two passes through the parser. If completion
    // is being performed short-circuit on the first pass.
    if (shortCircuit) {
      return argv
    }

    // if there's a handler associated with a
    // command defer processing to it.
    if (helpOpt) {
      // consider any multi-char helpOpt alias as a valid help command
      // unless all helpOpt aliases are single-char
      // note that parsed.aliases is a normalized bidirectional map :)
      const helpCmds = [helpOpt]
        .concat(aliases[helpOpt] || [])
        .filter(k => k.length > 1)
      // check if help should trigger and strip it from _.
      if (~helpCmds.indexOf(argv._[argv._.length - 1])) {
        argv._.pop()
        argv[helpOpt] = true
      }
    }

    const handlerKeys = command.getCommands()
    const requestCompletions = completion.completionKey in argv
    const skipRecommendation = argv[helpOpt] || requestCompletions
    const skipDefaultCommand = skipRecommendation && (handlerKeys.length > 1 || handlerKeys[0] !== '$0')

    if (argv._.length) {
      if (handlerKeys.length) {
        let firstUnknownCommand
        for (let i = (commandIndex || 0), cmd; argv._[i] !== undefined; i++) {
          cmd = String(argv._[i])
          if (~handlerKeys.indexOf(cmd) && cmd !== completionCommand) {
            // commands are executed using a recursive algorithm that executes
            // the deepest command first; we keep track of the position in the
            // argv._ array that is currently being executed.
            return command.runCommand(cmd, self, parsed, i + 1)
          } else if (!firstUnknownCommand && cmd !== completionCommand) {
            firstUnknownCommand = cmd
            break
          }
        }

        // run the default command, if defined
        if (command.hasDefaultCommand() && !skipDefaultCommand) {
          return command.runCommand(null, self, parsed)
        }

        // recommend a command if recommendCommands() has
        // been enabled, and no commands were found to execute
        if (recommendCommands && firstUnknownCommand && !skipRecommendation) {
          validation.recommendCommands(firstUnknownCommand, handlerKeys)
        }
      }

      // generate a completion script for adding to ~/.bashrc.
      if (completionCommand && ~argv._.indexOf(completionCommand) && !requestCompletions) {
        if (exitProcess) setBlocking(true)
        self.showCompletionScript()
        self.exit(0)
      }
    } else if (command.hasDefaultCommand() && !skipDefaultCommand) {
      return command.runCommand(null, self, parsed)
    }

    // we must run completions first, a user might
    // want to complete the --help or --version option.
    if (requestCompletions) {
      if (exitProcess) setBlocking(true)

      // we allow for asynchronous completions,
      // e.g., loading in a list of commands from an API.
      const completionArgs = args.slice(args.indexOf(`--${completion.completionKey}`) + 1)
      completion.getCompletion(completionArgs, (completions) => {
        ;(completions || []).forEach((completion) => {
          _logger.log(completion)
        })

        self.exit(0)
      })
      return argv
    }

    // Handle 'help' and 'version' options
    // if we haven't already output help!
    if (!hasOutput) {
      Object.keys(argv).forEach((key) => {
        if (key === helpOpt && argv[key]) {
          if (exitProcess) setBlocking(true)

          skipValidation = true
          self.showHelp('log')
          self.exit(0)
        } else if (key === versionOpt && argv[key]) {
          if (exitProcess) setBlocking(true)

          skipValidation = true
          usage.showVersion()
          self.exit(0)
        }
      })
    }

    // Check if any of the options to skip validation were provided
    if (!skipValidation && options.skipValidation.length > 0) {
      skipValidation = Object.keys(argv).some(key => options.skipValidation.indexOf(key) >= 0 && argv[key] === true)
    }

    // If the help or version options where used and exitProcess is false,
    // or if explicitly skipped, we won't run validations.
    if (!skipValidation) {
      if (parsed.error) throw new YError(parsed.error.message)

      // if we're executed via bash completion, don't
      // bother with validation.
      if (!requestCompletions) {
        self._runValidation(argv, aliases, {}, parsed.error)
      }
    }
  } catch (err) {
    if (err instanceof YError) usage.fail(err.message, err)
    else throw err
  }

  return argv
}

self._runValidation = function runValidation (argv, aliases, positionalMap, parseErrors) {
  if (parseErrors) throw new YError(parseErrors.message || parseErrors)
  validation.nonOptionCount(argv)
  validation.requiredArguments(argv)
  if (strict) validation.unknownArguments(argv, aliases, positionalMap)
  validation.customChecks(argv, aliases)
  validation.limitedChoices(argv)
  validation.implications(argv)
  validation.conflicting(argv)
}

function guessLocale () {
  if (!detectLocale) return

  try {
    const { env } = process
    const locale = env.LC_ALL || env.LC_MESSAGES || env.LANG || env.LANGUAGE || 'en_US'
    self.locale(locale.replace(/[.:].*/, ''))
  } catch (err) {
    // if we explode looking up locale just noop
    // we'll keep using the default language 'en'.
  }
}

// an app should almost always have --version and --help,
// if you *really* want to disable this use .help(false)/.version(false).
self.help()
self.version()

return self

}

// rebase an absolute path to a relative one with respect to a base directory // exported for tests exports.rebase = rebase function rebase (base, dir) {

return path.relative(base, dir)

}