package opus

import (
	"context"
	"log"
	"os"
	"sync"
	"testing"
	"time"

	"github.com/gopxl/beep"
)

var (
	mu        sync.Mutex
	mixer     beep.Mixer
	frameSize int = 960
	samples       = make([][2]float64, frameSize)
	buf       []byte
	maxBytes  int = (frameSize * 2) * 2
	done      chan struct{}
	f         beep.Format
)

func update() {
	mu.Lock()
	mixer.Stream(samples)
	mu.Unlock()

	for i := range samples {
		for c := range samples[i] {
			val := samples[i][c]
			if val < -1 {
				val = -1
			}
			if val > +1 {
				val = +1
			}
			valInt16 := int16(val * (1<<15 - 1))
			low := byte(valInt16)
			high := byte(valInt16 >> 8)
			buf[i*4+c*2+0] = low
			buf[i*4+c*2+1] = high
		}
	}

	//log.Printf("%+v", buf)
}

func TestMain(t *testing.T) {
	buf = make([]byte, maxBytes)

	ctx, cancel := context.WithTimeout(context.Background(), time.Minute*9)
	defer cancel()

	file, err := os.Open("test.opus")
	if err != nil {
		log.Fatal(err)
	}

	d, err := New(file)
	if err != nil {
		log.Fatal(err)
	}

	f = beep.Format{
		SampleRate:  beep.SampleRate(48000),
		NumChannels: 2,
		Precision:   2,
	}

	loop := beep.Loop(-1, d)

	mu.Lock()
	mixer.Add(loop)
	mu.Unlock()

	for {
		select {
		default:
			update()
		case <-ctx.Done():
			return
		}
	}
}