let rTrue=['t','true','y','yes','on','affirmative','positive','up','enabled','affirmative','yea','yep','sure','online','set','closed']
let rFalse=['f','false','n','no','off','negative','negatory','down','disabled','nope','offline','unset','open']

function createBoolean (opts={}) {
  return (value => {
    if (opts.addTrue) rTrue = rTrue.concat(opts.addTrue)
    if (opts.addFalse) rFalse = rFalse.concat(opts.addFalse)
    if (opts.True) rTrue = opts.True
    if (opts.False) rFalse = opts.False
    if (value===undefined) return opts.undefined==='same' ? undefined : (opts.undefined || false) // false by default
    if (value===null) return opts.null==='same' ? null : (opts.null || false) // false by default
    if (!isNaN(Number(value))) return (opts.number==='default' ? !!value : (Number(value) > (opts.number || 0)? true : false))
    if (typeof value==='string') {
      value = value.trim()
      value = value.toLowerCase()
      if (rTrue.includes(value)) return true
      if (rFalse.includes(value)) return false
      return !!opts.string || false
    }
    return !!value
  })
}

const toBoolean = createBoolean()

export default toBoolean
export { toBoolean, createBoolean, rTrue, rFalse }