var camelCase = require('camelcase') var decamelize = require('decamelize') var path = require('path') var tokenizeArgString = require('./lib/tokenize-arg-string') var util = require('util')

function parse (args, opts) {

if (!opts) opts = {}
// allow a string argument to be passed in rather
// than an argv array.
args = tokenizeArgString(args)

// aliases might have transitive relationships, normalize this.
var aliases = combineAliases(opts.alias || {})
var configuration = Object.assign({
  'short-option-groups': true,
  'camel-case-expansion': true,
  'dot-notation': true,
  'parse-numbers': true,
  'boolean-negation': true,
  'negation-prefix': 'no-',
  'duplicate-arguments-array': true,
  'flatten-duplicate-arrays': true,
  'populate--': false,
  'combine-arrays': false,
  'set-placeholder-key': false,
  'halt-at-non-option': false,
  'strip-aliased': false,
  'strip-dashed': false
}, opts.configuration)
var defaults = opts.default || {}
var configObjects = opts.configObjects || []
var envPrefix = opts.envPrefix
var notFlagsOption = configuration['populate--']
var notFlagsArgv = notFlagsOption ? '--' : '_'
var newAliases = {}
// allow a i18n handler to be passed in, default to a fake one (util.format).
var __ = opts.__ || util.format
var error = null
var flags = {
  aliases: {},
  arrays: {},
  bools: {},
  strings: {},
  numbers: {},
  counts: {},
  normalize: {},
  configs: {},
  defaulted: {},
  nargs: {},
  coercions: {},
  keys: []
}
var negative = /^-[0-9]+(\.[0-9]+)?/
var negatedBoolean = new RegExp('^--' + configuration['negation-prefix'] + '(.+)')

;[].concat(opts.array).filter(Boolean).forEach(function (opt) {
  var key = opt.key || opt

  // assign to flags[bools|strings|numbers]
  const assignment = Object.keys(opt).map(function (key) {
    return ({
      boolean: 'bools',
      string: 'strings',
      number: 'numbers'
    })[key]
  }).filter(Boolean).pop()

  // assign key to be coerced
  if (assignment) {
    flags[assignment][key] = true
  }

  flags.arrays[key] = true
  flags.keys.push(key)
})

;[].concat(opts.boolean).filter(Boolean).forEach(function (key) {
  flags.bools[key] = true
  flags.keys.push(key)
})

;[].concat(opts.string).filter(Boolean).forEach(function (key) {
  flags.strings[key] = true
  flags.keys.push(key)
})

;[].concat(opts.number).filter(Boolean).forEach(function (key) {
  flags.numbers[key] = true
  flags.keys.push(key)
})

;[].concat(opts.count).filter(Boolean).forEach(function (key) {
  flags.counts[key] = true
  flags.keys.push(key)
})

;[].concat(opts.normalize).filter(Boolean).forEach(function (key) {
  flags.normalize[key] = true
  flags.keys.push(key)
})

Object.keys(opts.narg || {}).forEach(function (k) {
  flags.nargs[k] = opts.narg[k]
  flags.keys.push(k)
})

Object.keys(opts.coerce || {}).forEach(function (k) {
  flags.coercions[k] = opts.coerce[k]
  flags.keys.push(k)
})

if (Array.isArray(opts.config) || typeof opts.config === 'string') {
  ;[].concat(opts.config).filter(Boolean).forEach(function (key) {
    flags.configs[key] = true
  })
} else {
  Object.keys(opts.config || {}).forEach(function (k) {
    flags.configs[k] = opts.config[k]
  })
}

// create a lookup table that takes into account all
// combinations of aliases: {f: ['foo'], foo: ['f']}
extendAliases(opts.key, aliases, opts.default, flags.arrays)

// apply default values to all aliases.
Object.keys(defaults).forEach(function (key) {
  (flags.aliases[key] || []).forEach(function (alias) {
    defaults[alias] = defaults[key]
  })
})

var argv = { _: [] }

Object.keys(flags.bools).forEach(function (key) {
  if (Object.prototype.hasOwnProperty.call(defaults, key)) {
    setArg(key, defaults[key])
    setDefaulted(key)
  }
})

var notFlags = []

for (var i = 0; i < args.length; i++) {
  var arg = args[i]
  var broken
  var key
  var letters
  var m
  var next
  var value

  // -- separated by =
  if (arg.match(/^--.+=/) || (
    !configuration['short-option-groups'] && arg.match(/^-.+=/)
  )) {
    // Using [\s\S] instead of . because js doesn't support the
    // 'dotall' regex modifier. See:
    // http://stackoverflow.com/a/1068308/13216
    m = arg.match(/^--?([^=]+)=([\s\S]*)$/)

    // nargs format = '--f=monkey washing cat'
    if (checkAllAliases(m[1], flags.nargs)) {
      args.splice(i + 1, 0, m[2])
      i = eatNargs(i, m[1], args)
    // arrays format = '--f=a b c'
    } else if (checkAllAliases(m[1], flags.arrays) && args.length > i + 1) {
      args.splice(i + 1, 0, m[2])
      i = eatArray(i, m[1], args)
    } else {
      setArg(m[1], m[2])
    }
  } else if (arg.match(negatedBoolean) && configuration['boolean-negation']) {
    key = arg.match(negatedBoolean)[1]
    setArg(key, false)

  // -- seperated by space.
  } else if (arg.match(/^--.+/) || (
    !configuration['short-option-groups'] && arg.match(/^-[^-]+/)
  )) {
    key = arg.match(/^--?(.+)/)[1]

    // nargs format = '--foo a b c'
    if (checkAllAliases(key, flags.nargs)) {
      i = eatNargs(i, key, args)
    // array format = '--foo a b c'
    } else if (checkAllAliases(key, flags.arrays) && args.length > i + 1) {
      i = eatArray(i, key, args)
    } else {
      next = flags.nargs[key] === 0 ? undefined : args[i + 1]

      if (next !== undefined && (!next.match(/^-/) ||
        next.match(negative)) &&
        !checkAllAliases(key, flags.bools) &&
        !checkAllAliases(key, flags.counts)) {
        setArg(key, next)
        i++
      } else if (/^(true|false)$/.test(next)) {
        setArg(key, next)
        i++
      } else {
        setArg(key, defaultValue(key))
      }
    }

  // dot-notation flag seperated by '='.
  } else if (arg.match(/^-.\..+=/)) {
    m = arg.match(/^-([^=]+)=([\s\S]*)$/)
    setArg(m[1], m[2])

  // dot-notation flag seperated by space.
  } else if (arg.match(/^-.\..+/)) {
    next = args[i + 1]
    key = arg.match(/^-(.\..+)/)[1]

    if (next !== undefined && !next.match(/^-/) &&
      !checkAllAliases(key, flags.bools) &&
      !checkAllAliases(key, flags.counts)) {
      setArg(key, next)
      i++
    } else {
      setArg(key, defaultValue(key))
    }
  } else if (arg.match(/^-[^-]+/) && !arg.match(negative)) {
    letters = arg.slice(1, -1).split('')
    broken = false

    for (var j = 0; j < letters.length; j++) {
      next = arg.slice(j + 2)

      if (letters[j + 1] && letters[j + 1] === '=') {
        value = arg.slice(j + 3)
        key = letters[j]

        // nargs format = '-f=monkey washing cat'
        if (checkAllAliases(key, flags.nargs)) {
          args.splice(i + 1, 0, value)
          i = eatNargs(i, key, args)
        // array format = '-f=a b c'
        } else if (checkAllAliases(key, flags.arrays) && args.length > i + 1) {
          args.splice(i + 1, 0, value)
          i = eatArray(i, key, args)
        } else {
          setArg(key, value)
        }

        broken = true
        break
      }

      if (next === '-') {
        setArg(letters[j], next)
        continue
      }

      // current letter is an alphabetic character and next value is a number
      if (/[A-Za-z]/.test(letters[j]) &&
        /^-?\d+(\.\d*)?(e-?\d+)?$/.test(next)) {
        setArg(letters[j], next)
        broken = true
        break
      }

      if (letters[j + 1] && letters[j + 1].match(/\W/)) {
        setArg(letters[j], next)
        broken = true
        break
      } else {
        setArg(letters[j], defaultValue(letters[j]))
      }
    }

    key = arg.slice(-1)[0]

    if (!broken && key !== '-') {
      // nargs format = '-f a b c'
      if (checkAllAliases(key, flags.nargs)) {
        i = eatNargs(i, key, args)
      // array format = '-f a b c'
      } else if (checkAllAliases(key, flags.arrays) && args.length > i + 1) {
        i = eatArray(i, key, args)
      } else {
        next = args[i + 1]

        if (next !== undefined && (!/^(-|--)[^-]/.test(next) ||
          next.match(negative)) &&
          !checkAllAliases(key, flags.bools) &&
          !checkAllAliases(key, flags.counts)) {
          setArg(key, next)
          i++
        } else if (/^(true|false)$/.test(next)) {
          setArg(key, next)
          i++
        } else {
          setArg(key, defaultValue(key))
        }
      }
    }
  } else if (arg === '--') {
    notFlags = args.slice(i + 1)
    break
  } else if (configuration['halt-at-non-option']) {
    notFlags = args.slice(i)
    break
  } else {
    argv._.push(maybeCoerceNumber('_', arg))
  }
}

// order of precedence:
// 1. command line arg
// 2. value from env var
// 3. value from config file
// 4. value from config objects
// 5. configured default value
applyEnvVars(argv, true) // special case: check env vars that point to config file
applyEnvVars(argv, false)
setConfig(argv)
setConfigObjects()
applyDefaultsAndAliases(argv, flags.aliases, defaults)
applyCoercions(argv)
if (configuration['set-placeholder-key']) setPlaceholderKeys(argv)

// for any counts either not in args or without an explicit default, set to 0
Object.keys(flags.counts).forEach(function (key) {
  if (!hasKey(argv, key.split('.'))) setArg(key, 0)
})

// '--' defaults to undefined.
if (notFlagsOption && notFlags.length) argv[notFlagsArgv] = []
notFlags.forEach(function (key) {
  argv[notFlagsArgv].push(key)
})

if (configuration['camel-case-expansion'] && configuration['strip-dashed']) {
  Object.keys(argv).filter(key => key !== '--' && key.includes('-')).forEach(key => {
    delete argv[key]
  })
}

if (configuration['strip-aliased']) {
  // XXX Switch to [].concat(...Object.values(aliases)) once node.js 6 is dropped
  ;[].concat(...Object.keys(aliases).map(k => aliases[k])).forEach(alias => {
    if (configuration['camel-case-expansion']) {
      delete argv[alias.split('.').map(prop => camelCase(prop)).join('.')]
    }

    delete argv[alias]
  })
}

// how many arguments should we consume, based
// on the nargs option?
function eatNargs (i, key, args) {
  var ii
  const toEat = checkAllAliases(key, flags.nargs)

  // nargs will not consume flag arguments, e.g., -abc, --foo,
  // and terminates when one is observed.
  var available = 0
  for (ii = i + 1; ii < args.length; ii++) {
    if (!args[ii].match(/^-[^0-9]/)) available++
    else break
  }

  if (available < toEat) error = Error(__('Not enough arguments following: %s', key))

  const consumed = Math.min(available, toEat)
  for (ii = i + 1; ii < (consumed + i + 1); ii++) {
    setArg(key, args[ii])
  }

  return (i + consumed)
}

// if an option is an array, eat all non-hyphenated arguments
// following it... YUM!
// e.g., --foo apple banana cat becomes ["apple", "banana", "cat"]
function eatArray (i, key, args) {
  var start = i + 1
  var argsToSet = []
  var multipleArrayFlag = i > 0
  for (var ii = i + 1; ii < args.length; ii++) {
    if (/^-/.test(args[ii]) && !negative.test(args[ii])) {
      if (ii === start) {
        setArg(key, defaultForType('array'))
      }
      multipleArrayFlag = true
      break
    }
    i = ii
    argsToSet.push(args[ii])
  }
  if (multipleArrayFlag) {
    setArg(key, argsToSet.map(function (arg) {
      return processValue(key, arg)
    }))
  } else {
    argsToSet.forEach(function (arg) {
      setArg(key, arg)
    })
  }

  return i
}

function setArg (key, val) {
  unsetDefaulted(key)

  if (/-/.test(key) && configuration['camel-case-expansion']) {
    var alias = key.split('.').map(function (prop) {
      return camelCase(prop)
    }).join('.')
    addNewAlias(key, alias)
  }

  var value = processValue(key, val)

  var splitKey = key.split('.')
  setKey(argv, splitKey, value)

  // handle populating aliases of the full key
  if (flags.aliases[key]) {
    flags.aliases[key].forEach(function (x) {
      x = x.split('.')
      setKey(argv, x, value)
    })
  }

  // handle populating aliases of the first element of the dot-notation key
  if (splitKey.length > 1 && configuration['dot-notation']) {
    ;(flags.aliases[splitKey[0]] || []).forEach(function (x) {
      x = x.split('.')

      // expand alias with nested objects in key
      var a = [].concat(splitKey)
      a.shift() // nuke the old key.
      x = x.concat(a)

      setKey(argv, x, value)
    })
  }

  // Set normalize getter and setter when key is in 'normalize' but isn't an array
  if (checkAllAliases(key, flags.normalize) && !checkAllAliases(key, flags.arrays)) {
    var keys = [key].concat(flags.aliases[key] || [])
    keys.forEach(function (key) {
      argv.__defineSetter__(key, function (v) {
        val = path.normalize(v)
      })

      argv.__defineGetter__(key, function () {
        return typeof val === 'string' ? path.normalize(val) : val
      })
    })
  }
}

function addNewAlias (key, alias) {
  if (!(flags.aliases[key] && flags.aliases[key].length)) {
    flags.aliases[key] = [alias]
    newAliases[alias] = true
  }
  if (!(flags.aliases[alias] && flags.aliases[alias].length)) {
    addNewAlias(alias, key)
  }
}

function processValue (key, val) {
  // strings may be quoted, clean this up as we assign values.
  if (typeof val === 'string' &&
    (val[0] === "'" || val[0] === '"') &&
    val[val.length - 1] === val[0]
  ) {
    val = val.substring(1, val.length - 1)
  }

  // handle parsing boolean arguments --foo=true --bar false.
  if (checkAllAliases(key, flags.bools) || checkAllAliases(key, flags.counts)) {
    if (typeof val === 'string') val = val === 'true'
  }

  var value = maybeCoerceNumber(key, val)

  // increment a count given as arg (either no value or value parsed as boolean)
  if (checkAllAliases(key, flags.counts) && (isUndefined(value) || typeof value === 'boolean')) {
    value = increment
  }

  // Set normalized value when key is in 'normalize' and in 'arrays'
  if (checkAllAliases(key, flags.normalize) && checkAllAliases(key, flags.arrays)) {
    if (Array.isArray(val)) value = val.map(path.normalize)
    else value = path.normalize(val)
  }
  return value
}

function maybeCoerceNumber (key, value) {
  if (!checkAllAliases(key, flags.strings) && !checkAllAliases(key, flags.coercions)) {
    const shouldCoerceNumber = isNumber(value) && configuration['parse-numbers'] && (
      Number.isSafeInteger(Math.floor(value))
    )
    if (shouldCoerceNumber || (!isUndefined(value) && checkAllAliases(key, flags.numbers))) value = Number(value)
  }
  return value
}

// set args from config.json file, this should be
// applied last so that defaults can be applied.
function setConfig (argv) {
  var configLookup = {}

  // expand defaults/aliases, in-case any happen to reference
  // the config.json file.
  applyDefaultsAndAliases(configLookup, flags.aliases, defaults)

  Object.keys(flags.configs).forEach(function (configKey) {
    var configPath = argv[configKey] || configLookup[configKey]
    if (configPath) {
      try {
        var config = null
        var resolvedConfigPath = path.resolve(process.cwd(), configPath)

        if (typeof flags.configs[configKey] === 'function') {
          try {
            config = flags.configs[configKey](resolvedConfigPath)
          } catch (e) {
            config = e
          }
          if (config instanceof Error) {
            error = config
            return
          }
        } else {
          config = require(resolvedConfigPath)
        }

        setConfigObject(config)
      } catch (ex) {
        if (argv[configKey]) error = Error(__('Invalid JSON config file: %s', configPath))
      }
    }
  })
}

// set args from config object.
// it recursively checks nested objects.
function setConfigObject (config, prev) {
  Object.keys(config).forEach(function (key) {
    var value = config[key]
    var fullKey = prev ? prev + '.' + key : key

    // if the value is an inner object and we have dot-notation
    // enabled, treat inner objects in config the same as
    // heavily nested dot notations (foo.bar.apple).
    if (typeof value === 'object' && value !== null && !Array.isArray(value) && configuration['dot-notation']) {
      // if the value is an object but not an array, check nested object
      setConfigObject(value, fullKey)
    } else {
      // setting arguments via CLI takes precedence over
      // values within the config file.
      if (!hasKey(argv, fullKey.split('.')) || (flags.defaulted[fullKey]) || (flags.arrays[fullKey] && configuration['combine-arrays'])) {
        setArg(fullKey, value)
      }
    }
  })
}

// set all config objects passed in opts
function setConfigObjects () {
  if (typeof configObjects === 'undefined') return
  configObjects.forEach(function (configObject) {
    setConfigObject(configObject)
  })
}

function applyEnvVars (argv, configOnly) {
  if (typeof envPrefix === 'undefined') return

  var prefix = typeof envPrefix === 'string' ? envPrefix : ''
  Object.keys(process.env).forEach(function (envVar) {
    if (prefix === '' || envVar.lastIndexOf(prefix, 0) === 0) {
      // get array of nested keys and convert them to camel case
      var keys = envVar.split('__').map(function (key, i) {
        if (i === 0) {
          key = key.substring(prefix.length)
        }
        return camelCase(key)
      })

      if (((configOnly && flags.configs[keys.join('.')]) || !configOnly) && (!hasKey(argv, keys) || flags.defaulted[keys.join('.')])) {
        setArg(keys.join('.'), process.env[envVar])
      }
    }
  })
}

function applyCoercions (argv) {
  var coerce
  var applied = {}
  Object.keys(argv).forEach(function (key) {
    if (!applied.hasOwnProperty(key)) { // If we haven't already coerced this option via one of its aliases
      coerce = checkAllAliases(key, flags.coercions)
      if (typeof coerce === 'function') {
        try {
          var value = coerce(argv[key])
          ;([].concat(flags.aliases[key] || [], key)).forEach(ali => {
            applied[ali] = argv[ali] = value
          })
        } catch (err) {
          error = err
        }
      }
    }
  })
}

function setPlaceholderKeys (argv) {
  flags.keys.forEach((key) => {
    // don't set placeholder keys for dot notation options 'foo.bar'.
    if (~key.indexOf('.')) return
    if (typeof argv[key] === 'undefined') argv[key] = undefined
  })
  return argv
}

function applyDefaultsAndAliases (obj, aliases, defaults) {
  Object.keys(defaults).forEach(function (key) {
    if (!hasKey(obj, key.split('.'))) {
      setKey(obj, key.split('.'), defaults[key])

      ;(aliases[key] || []).forEach(function (x) {
        if (hasKey(obj, x.split('.'))) return
        setKey(obj, x.split('.'), defaults[key])
      })
    }
  })
}

function hasKey (obj, keys) {
  var o = obj

  if (!configuration['dot-notation']) keys = [keys.join('.')]

  keys.slice(0, -1).forEach(function (key) {
    o = (o[key] || {})
  })

  var key = keys[keys.length - 1]

  if (typeof o !== 'object') return false
  else return key in o
}

function setKey (obj, keys, value) {
  var o = obj

  if (!configuration['dot-notation']) keys = [keys.join('.')]

  keys.slice(0, -1).forEach(function (key, index) {
    if (typeof o === 'object' && o[key] === undefined) {
      o[key] = {}
    }

    if (typeof o[key] !== 'object' || Array.isArray(o[key])) {
      // ensure that o[key] is an array, and that the last item is an empty object.
      if (Array.isArray(o[key])) {
        o[key].push({})
      } else {
        o[key] = [o[key], {}]
      }

      // we want to update the empty object at the end of the o[key] array, so set o to that object
      o = o[key][o[key].length - 1]
    } else {
      o = o[key]
    }
  })

  var key = keys[keys.length - 1]

  var isTypeArray = checkAllAliases(keys.join('.'), flags.arrays)
  var isValueArray = Array.isArray(value)
  var duplicate = configuration['duplicate-arguments-array']

  // nargs has higher priority than duplicate
  if (!duplicate && checkAllAliases(key, flags.nargs)) {
    duplicate = true
    if ((!isUndefined(o[key]) && flags.nargs[key] === 1) || (Array.isArray(o[key]) && o[key].length === flags.nargs[key])) {
      o[key] = undefined
    }
  }

  if (value === increment) {
    o[key] = increment(o[key])
  } else if (Array.isArray(o[key])) {
    if (duplicate && isTypeArray && isValueArray) {
      o[key] = configuration['flatten-duplicate-arrays'] ? o[key].concat(value) : (Array.isArray(o[key][0]) ? o[key] : [o[key]]).concat([value])
    } else if (!duplicate && Boolean(isTypeArray) === Boolean(isValueArray)) {
      o[key] = value
    } else {
      o[key] = o[key].concat([value])
    }
  } else if (o[key] === undefined && isTypeArray) {
    o[key] = isValueArray ? value : [value]
  } else if (duplicate && !(o[key] === undefined || checkAllAliases(key, flags.bools) || checkAllAliases(keys.join('.'), flags.bools) || checkAllAliases(key, flags.counts))) {
    o[key] = [ o[key], value ]
  } else {
    o[key] = value
  }
}

// extend the aliases list with inferred aliases.
function extendAliases (...args) {
  args.forEach(function (obj) {
    Object.keys(obj || {}).forEach(function (key) {
      // short-circuit if we've already added a key
      // to the aliases array, for example it might
      // exist in both 'opts.default' and 'opts.key'.
      if (flags.aliases[key]) return

      flags.aliases[key] = [].concat(aliases[key] || [])
      // For "--option-name", also set argv.optionName
      flags.aliases[key].concat(key).forEach(function (x) {
        if (/-/.test(x) && configuration['camel-case-expansion']) {
          var c = camelCase(x)
          if (c !== key && flags.aliases[key].indexOf(c) === -1) {
            flags.aliases[key].push(c)
            newAliases[c] = true
          }
        }
      })
      // For "--optionName", also set argv['option-name']
      flags.aliases[key].concat(key).forEach(function (x) {
        if (x.length > 1 && /[A-Z]/.test(x) && configuration['camel-case-expansion']) {
          var c = decamelize(x, '-')
          if (c !== key && flags.aliases[key].indexOf(c) === -1) {
            flags.aliases[key].push(c)
            newAliases[c] = true
          }
        }
      })
      flags.aliases[key].forEach(function (x) {
        flags.aliases[x] = [key].concat(flags.aliases[key].filter(function (y) {
          return x !== y
        }))
      })
    })
  })
}

// check if a flag is set for any of a key's aliases.
function checkAllAliases (key, flag) {
  var isSet = false
  var toCheck = [].concat(flags.aliases[key] || [], key)

  toCheck.forEach(function (key) {
    if (flag[key]) isSet = flag[key]
  })

  return isSet
}

function setDefaulted (key) {
  [].concat(flags.aliases[key] || [], key).forEach(function (k) {
    flags.defaulted[k] = true
  })
}

function unsetDefaulted (key) {
  [].concat(flags.aliases[key] || [], key).forEach(function (k) {
    delete flags.defaulted[k]
  })
}

// make a best effor to pick a default value
// for an option based on name and type.
function defaultValue (key) {
  if (!checkAllAliases(key, flags.bools) &&
      !checkAllAliases(key, flags.counts) &&
      `${key}` in defaults) {
    return defaults[key]
  } else {
    return defaultForType(guessType(key))
  }
}

// return a default value, given the type of a flag.,
// e.g., key of type 'string' will default to '', rather than 'true'.
function defaultForType (type) {
  var def = {
    boolean: true,
    string: '',
    number: undefined,
    array: []
  }

  return def[type]
}

// given a flag, enforce a default type.
function guessType (key) {
  var type = 'boolean'

  if (checkAllAliases(key, flags.strings)) type = 'string'
  else if (checkAllAliases(key, flags.numbers)) type = 'number'
  else if (checkAllAliases(key, flags.arrays)) type = 'array'

  return type
}

function isNumber (x) {
  if (x === null || x === undefined) return false
  // if loaded from config, may already be a number.
  if (typeof x === 'number') return true
  // hexadecimal.
  if (/^0x[0-9a-f]+$/i.test(x)) return true
  // don't treat 0123 as a number; as it drops the leading '0'.
  if (x.length > 1 && x[0] === '0') return false
  return /^[-]?(?:\d+(?:\.\d*)?|\.\d+)(e[-+]?\d+)?$/.test(x)
}

function isUndefined (num) {
  return num === undefined
}

return {
  argv: argv,
  error: error,
  aliases: flags.aliases,
  newAliases: newAliases,
  configuration: configuration
}

}

// if any aliases reference each other, we should // merge them together. function combineAliases (aliases) {

var aliasArrays = []
var change = true
var combined = {}

// turn alias lookup hash {key: ['alias1', 'alias2']} into
// a simple array ['key', 'alias1', 'alias2']
Object.keys(aliases).forEach(function (key) {
  aliasArrays.push(
    [].concat(aliases[key], key)
  )
})

// combine arrays until zero changes are
// made in an iteration.
while (change) {
  change = false
  for (var i = 0; i < aliasArrays.length; i++) {
    for (var ii = i + 1; ii < aliasArrays.length; ii++) {
      var intersect = aliasArrays[i].filter(function (v) {
        return aliasArrays[ii].indexOf(v) !== -1
      })

      if (intersect.length) {
        aliasArrays[i] = aliasArrays[i].concat(aliasArrays[ii])
        aliasArrays.splice(ii, 1)
        change = true
        break
      }
    }
  }
}

// map arrays back to the hash-lookup (de-dupe while
// we're at it).
aliasArrays.forEach(function (aliasArray) {
  aliasArray = aliasArray.filter(function (v, i, self) {
    return self.indexOf(v) === i
  })
  combined[aliasArray.pop()] = aliasArray
})

return combined

}

// this function should only be called when a count is given as an arg // it is NOT called to set a default value // thus we can start the count at 1 instead of 0 function increment (orig) {

return orig !== undefined ? orig + 1 : 1

}

function Parser (args, opts) {

var result = parse(args.slice(), opts)

return result.argv

}

// parse arguments and return detailed // meta information, aliases, etc. Parser.detailed = function (args, opts) {

return parse(args.slice(), opts)

}

module.exports = Parser