/** URL parse / join for summon (about:, file:, http:, https:). */

var BARE_SUMMON_SCHEMES = {
  http: true,
  https: true,
  file: true,
  about: true
}

function bareSummonTrim(s) {
  return String(s == null ? '' : s).trim()
}

function bareSummonParseUrl(raw) {
  var s = bareSummonTrim(raw)
  if (!s) return null
  if (s.indexOf('://') < 0 && s.indexOf(':') > 0) {
    var sch0 = s.slice(0, s.indexOf(':')).toLowerCase()
    if (sch0 === 'about') {
      return {
        href: 'about:' + s.slice(s.indexOf(':') + 1),
        protocol: 'about:',
        host: '',
        hostname: '',
        port: '',
        pathname: s.slice(s.indexOf(':') + 1) || 'blank',
        search: '',
        hash: '',
        origin: 'about:'
      }
    }
  }
  try {
    var u = new URL(s)
    return {
      href: u.href,
      protocol: u.protocol,
      host: u.host,
      hostname: u.hostname,
      port: u.port,
      pathname: u.pathname || '/',
      search: u.search,
      hash: u.hash,
      origin: u.origin
    }
  } catch (e) {
    return null
  }
}

function bareSummonResolveUrl(ref, base) {
  var r = bareSummonTrim(ref)
  if (!r) return bareSummonParseUrl(base)
  if (/^javascript:/i.test(r)) return null
  if (r.charAt(0) === '#') {
    var b0 = bareSummonParseUrl(base)
    if (!b0) return null
    b0.hash = r
    b0.href = b0.href.split('#')[0] + r
    return b0
  }
  if (/^about:/i.test(r)) return bareSummonParseUrl(r)
  try {
    var u = base ? new URL(r, String(base)) : new URL(r)
    return bareSummonParseUrl(u.href)
  } catch (e2) {
    return null
  }
}

function bareSummonUrlOk(u) {
  if (!u || !u.protocol) return false
  var p = u.protocol.replace(/:$/, '')
  return !!BARE_SUMMON_SCHEMES[p]
}

function bareSummonIsHttp(u) {
  return u && (u.protocol === 'http:' || u.protocol === 'https:')
}