go-roflcopter/roflcopter/roflcopter.go

package roflcopter

import (
	"bytes"
	_ "embed"
	"io"
	"log"
	"sync"
	"time"

	"github.com/faiface/beep/mp3"
	"github.com/faiface/beep/speaker"
)

//go:embed embed\swah.mp3
var swah []byte

var (
	work     bool = true
	duration time.Duration
	inWork   *sync.WaitGroup
)

const (
	frame1 = " ROFL:ROFL:         \n         _^____		\n L    __/   [] \\	\n O ===__        \\	\n L      \\________]	\n         I   I		\n        --------/	\n"
	frame2 = "          :ROFL:ROFL\n         _^____ 	\n      __/   [] \\	\nLOL===__        \\	\n        \\________]	\n         I   I		\n        --------/	\n"
)

type Roflcopter struct {
	work   bool
	count  time.Duration
	str    *string
	runner func()
}

// NewRoflcopter creates a new instance of roflcopter. amount sets duration, outStr is used to output frames, funcrunner will be called after frame change
func NewRoflcopter(amount time.Duration, outStr *string, funcrunner func()) *Roflcopter {
	inWork = new(sync.WaitGroup)
	return &Roflcopter{
		work:   true,
		str:    outStr,
		count:  amount,
		runner: funcrunner,
	}
}

// Start starts frame changing. Soundplaying can be set by true or false. Returns WaitGroup to know when it has finished work.
func (b *Roflcopter) Start(playSound bool) *sync.WaitGroup {
	var wg *sync.WaitGroup = new(sync.WaitGroup)
	inWork.Add(1)
	*b.str = frame1 + b.count.String()
	work = b.work
	duration = b.count
	if playSound {
		go b.player(wg)
	}
	go b.timeCounter(500 * time.Millisecond)
	go b.frameChanger(125 * time.Millisecond)
	return inWork
}

// OnlySound only plays sound. Frames are not changing. Returns WaitGroup to know when it has finished work
func (b *Roflcopter) OnlySound() *sync.WaitGroup {
	var wg *sync.WaitGroup = new(sync.WaitGroup)
	inWork.Add(1)
	work = b.work
	duration = b.count
	go b.player(wg)
	go b.timeCounter(500 * time.Millisecond)
	return inWork
}

// timeCounter counts time and stops other work when time ends
func (b *Roflcopter) timeCounter(step time.Duration) {
	for duration > 0 {
		duration -= step
		time.Sleep(step)
	}
	work = false
	time.Sleep(100 * time.Millisecond)
}

//player is a loop to start sound play
func (b *Roflcopter) player(wg *sync.WaitGroup) {
	b.sound(wg)
	wg.Wait()
	if work {
		b.player(wg)
	} else {
		inWork.Done()
	}
}

//frameChanger is a loop to change frames
func (b *Roflcopter) frameChanger(delay time.Duration) {
	nextframe := 2

	for work {
		switch nextframe {
		case 1:
			{
				*b.str = frame1 + "Ends in " + duration.String()
				time.Sleep(delay)
				nextframe = 2
			}

		case 2:
			{
				*b.str = frame2 + "Ends in " + duration.String()
				time.Sleep(delay)
				nextframe = 1
			}
		}
		b.runner()
	}
	inWork.Done()
}

//sound plays sound
func (b *Roflcopter) sound(wg *sync.WaitGroup) {
	wg.Add(1)
	t := 1*time.Second + 380*time.Millisecond
	streamer, format, err := mp3.Decode(io.NopCloser(bytes.NewReader(swah)))
	if err != nil {
		log.Fatal(err)
	}
	defer streamer.Close()
	speaker.Init(format.SampleRate, format.SampleRate.N(time.Second/10))
	speaker.Play(streamer)
	time.Sleep(t * 1)
	wg.Done()
}