/*
Copyright 2014 Workiva, LLC

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

 http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package futures

import (
	"sync"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
)

func TestWaitOnGetResult(t *testing.T) {
	completer := make(chan interface{})
	f := New(completer, time.Duration(30*time.Minute))
	var result interface{}
	var err error
	var wg sync.WaitGroup
	wg.Add(1)
	go func() {
		result, err = f.GetResult()
		wg.Done()
	}()

	completer <- `test`
	wg.Wait()

	assert.Nil(t, err)
	assert.Equal(t, `test`, result)

	// ensure we don't get paused on the next iteration.
	result, err = f.GetResult()

	assert.Equal(t, `test`, result)
	assert.Nil(t, err)
}

func TestHasResult(t *testing.T) {
	completer := make(chan interface{})
	f := New(completer, time.Duration(30*time.Minute))

	assert.False(t, f.HasResult())

	var wg sync.WaitGroup
	wg.Add(1)
	go func() {
		f.GetResult()
		wg.Done()
	}()

	completer <- `test`
	wg.Wait()

	assert.True(t, f.HasResult())
}

func TestTimeout(t *testing.T) {
	completer := make(chan interface{})
	f := New(completer, time.Duration(0))

	result, err := f.GetResult()

	assert.Nil(t, result)
	assert.NotNil(t, err)
}

func BenchmarkFuture(b *testing.B) {
	completer := make(chan interface{})
	timeout := time.Duration(30 * time.Minute)
	var wg sync.WaitGroup

	b.ResetTimer()

	for i := 0; i < b.N; i++ {
		wg.Add(1)
		f := New(completer, timeout)
		go func() {
			f.GetResult()
			wg.Done()
		}()

		completer <- `test`
		wg.Wait()
	}
}