//go:build !disable_format_vorbis
// +build !disable_format_vorbis

package vorbis

import (
	"bytes"
	"git.gammaspectra.live/S.O.N.G/Kirika/audio"
	libvorbis "github.com/jfreymuth/oggvorbis"
	"io"
)

type Format struct {
}

func NewFormat() Format {
	return Format{}
}

func (f Format) Name() string {
	return "vorbis"
}

func (f Format) Description() string {
	return "jfreymuth/oggvorvis"
}

func (f Format) Open(r io.ReadSeekCloser) (audio.Source, error) {
	reader, err := libvorbis.NewReader(r)
	if err != nil {
		return audio.Source{}, err
	}

	newChannel := make(chan []float32)

	go func() {
		defer close(newChannel)

		for {

			buffer := make([]float32, 8192)

			n, err := reader.Read(buffer)
			if err != nil {
				return
			}

			if n > 0 {
				newChannel <- buffer[:n]
			}
		}
	}()

	//We always get two channels via stereo api
	return audio.Source{
		Channels:   reader.Channels(),
		SampleRate: reader.SampleRate(),
		Blocks:     newChannel,
	}, nil
}

func (f Format) Identify(peek []byte, extension string) bool {
	return bytes.Compare(peek[:4], []byte{'O', 'g', 'g', 'S'}) == 0 || extension == "vorbis" || extension == "ogg"
}