dndmusicbot/ambiance.go

package main

import (
	"bufio"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"os/exec"
	"path/filepath"
	"strings"

	"github.com/davecheney/xattr"
	"github.com/google/uuid"
)

var httpClient = new(http.Client)

type Ambiance struct {
	Id    string
	Title string
	Path  string
}

func GetAmbiance(id string) (amb Ambiance, err error) {
	fp := filepath.Join("./ambiance", id+".opus")
	_, err = os.Stat(fp)
	if err != nil {
		return
	}

	title, err := xattr.Getxattr(fp, "title")
	if err != nil {
		return
	}

	return Ambiance{
		Id:    id,
		Title: string(title),
		Path:  fp,
	}, nil
}

func GetAmbiances() (amb []Ambiance, err error) {
	files, err := os.ReadDir("./ambiance")
	if err != nil {
		return nil, err
	}

	for _, file := range files {
		title, err := xattr.Getxattr(filepath.Join("./ambiance", file.Name()), "title")
		if err != nil {
			return nil, err

		}
		amb = append(amb, Ambiance{
			Id:    file.Name()[:len(file.Name())-len(filepath.Ext(file.Name()))],
			Title: string(title),
			Path:  filepath.Join("./ambiance", file.Name()),
		})
	}

	return
}

func AddAmbiance(uri, title string) (Ambiance, error) {
	var amb Ambiance

	tmpfile, err := exec.Command("mktemp", "/tmp/dnd_XXXXXXXXXXXX.opus").Output()
	if err != nil {
		return amb, err
	}

	tmpfile = tmpfile[:len(tmpfile)-1]

	vid, err := YTUrl(uri)
	if err != nil {
		return amb, err
	}

	log.Printf("Start YTdl for %s", uri)
	dluri, err := NewYTdl(vid)
	if err != nil {
		return amb, err
	}

	log.Printf("Start download.. %s", uri)
	resp, err := httpClient.Get(string(dluri))
	if err != nil {
		return amb, err
	}
	defer resp.Body.Close()

	ff := exec.Command(
		"ffmpeg",
		"-y",
		"-i", "-",
		"-vn",
		"-acodec", "copy",
		"-movflags", "+faststart",
		"-t", "01:00:00",
		"-v", "error",
		// "-stats",
		"-progress", "pipe:1",
		// "-af", "loudnorm=I=-16:LRA=11:TP=-1.5",
		string(tmpfile),
	)

	ffprogress, err := ff.StdoutPipe()
	if err != nil {
		return amb, err
	}

	ff.Stderr = os.Stderr
	ff.Stdin = resp.Body

	err = ff.Start()
	if err != nil {
		return amb, err
	}

	log.Printf("Start ffmpeg to extract audio to %s", string(tmpfile))
	msg := make(map[string]interface{})
	msg["event"] = "ambiance_encode_start"
	data := make(map[string]string)
	data["name"] = title
	msg["payload"] = data
	ws_msg <- msg

	msg = make(map[string]interface{})
	msg["event"] = "ambiance_encode_progress"
	data = make(map[string]string)
	data["name"] = title

	scanner := bufio.NewScanner(ffprogress)

	for scanner.Scan() {
		p := strings.Split(scanner.Text(), "=")
		if len(p) == 2 {
			data[p[0]] = strings.TrimSpace(p[1])
		}

		prate.Do(func() {
			msg["payload"] = data
			ws_msg <- msg
		})
	}
	if err := scanner.Err(); err != nil {
		return amb, err
	}

	err = ff.Wait()
	if err != nil {
		return amb, err
	}

	msg = make(map[string]interface{})
	msg["event"] = "ambiance_encode_complete"
	data = make(map[string]string)
	data["name"] = title
	msg["payload"] = data
	ws_msg <- msg

	id := uuid.New()
	fn := filepath.Join("./ambiance", fmt.Sprintf("%s.opus", id.String()))

	log.Printf("Moving to %s", fn)

	in, err := os.Open(string(tmpfile))
	if err != nil {
		return amb, err
	}

	of, err := os.Create(fn)
	if err != nil {
		return amb, err
	}

	_, err = io.Copy(of, in)
	if err != nil {
		return amb, err
	}

	err = of.Sync()
	if err != nil {
		return amb, err
	}

	err = of.Close()
	if err != nil {
		return amb, err
	}

	err = in.Close()
	if err != nil {
		return amb, err
	}

	err = os.Remove(string(tmpfile))
	if err != nil {
		return amb, err
	}

	log.Println("Setting xattr")
	err = xattr.Setxattr(fn, "title", []byte(title))
	if err != nil {
		return amb, err
	}

	amb.Id = id.String()
	amb.Title = title

	log.Println("Return info.")
	return amb, nil
}