// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Test simple select.

'use strict'

const Channel = require('../../lib')

it(`select`, async function () {
  const closed = Channel()
  closed.close()
  let counter = 0
  let shift = 0

  const GetValue = () => {
    counter++
    return 1 << shift
  }

  const Send = async (a, b) => {
    let done = false
    let i = 0

    do {
      switch (await Channel.select(a.push(GetValue()), b.push(GetValue()),
        closed.shift())) {
        case a:
          i++
          a = Channel()
          break

        case b:
          i++
          b = Channel()
          break

        default:
          done = true
      }

      shift++
    } while (!done)

    return i
  }

  let a = Channel(1)
  let b = Channel(1)
  let v = await Send(a, b)

  if (v !== 2) {
    throw new Error(`Send returned ${v} !== 2`)
  }

  const av = await a.shift()
  const bv = await b.shift()

  if ((av | bv) !== 3) {
    throw new Error(`bad values ${av} ${bv}`)
  }

  v = await Send(a, Channel())

  if (v !== 1) {
    throw new Error(`Send returned ${v} !== 1`)
  }

  if (counter !== 10) {
    throw new Error(`counter is ${counter} !== 10`)
  }
})