//go:build linux || darwin
// +build linux darwin

package main

import (
	"fmt"
	"io"
	"os"

	"github.com/gen2brain/malgo"
	"github.com/youpy/go-wav"
)

func PlayWAVFile(filename string, stopPlaying *bool) error {
	file, err := os.Open(filename)
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
	defer file.Close()

	w := wav.NewReader(file)
	f, err := w.Format()
	if err != nil {
		return err
	}

	reader := w
	channels := uint32(f.NumChannels)
	sampleRate := f.SampleRate

	ctx, err := malgo.InitContext(nil, malgo.ContextConfig{}, func(message string) {
		fmt.Printf("LOG <%v>\n", message)
	})
	if err != nil {
		return err
	}
	defer func() {
		_ = ctx.Uninit()
		ctx.Free()
	}()

	deviceConfig := malgo.DefaultDeviceConfig(malgo.Playback)
	deviceConfig.Playback.Format = malgo.FormatS16
	deviceConfig.Playback.Channels = channels
	deviceConfig.SampleRate = sampleRate
	deviceConfig.Alsa.NoMMap = 1

	// This is the function that's used for sending more data to the device for playback.
	onSamples := func(pOutputSample, pInputSamples []byte, framecount uint32) {
		io.ReadFull(reader, pOutputSample)
	}

	deviceCallbacks := malgo.DeviceCallbacks{
		Data: onSamples,
	}

	device, err := malgo.InitDevice(ctx.Context, deviceConfig, deviceCallbacks)
	if err != nil {
		return err
	}
	defer device.Uninit()

	err = device.Start()
	if err != nil {
		return err
	}

	for device.IsStarted() {
		if *stopPlaying {
			break
		}
	}

	return nil
}