music.go

package main

import (
	"encoding/json"
	"os/exec"
)

// Song : Song information fetched from youtube-dl. More fields exist in the JSON response, but this is what we need.
type Song struct {
	Title      string `json:"title"`
	URL        string `json:"url"`
	Thumbnail  string `json:"thumbnail"`
	WebpageURL string `json:"webpage_url"`
}

func fetchSong(url string) (Song, error) {
	// Maybe make this function return a promise or something in the future
	var songData Song
	// JSON dump has no extra overhead, and we get more info that we need that might be useful
	cmd := exec.Command("youtube-dl", "--no-playlist", "-J", "--youtube-skip-dash-manifest", "-f bestaudio", url)
	stdOut, err := cmd.StdoutPipe()

	if err != nil {
		return Song{}, err
	}

	if err := cmd.Start(); err != nil {
		return Song{}, err
	}

	if err := json.NewDecoder(stdOut).Decode(&songData); err != nil {
		return Song{}, err
	}

	cmd.Wait()
	// Only using these fields atm
	return songData, nil
}