small refactor*

server/pkg/ytdlp/playlist.go

@@ -0,0 +1,115 @@
+package ytdlp
+
+import (
+	"bufio"
+	"context"
+	"encoding/json"
+	"errors"
+	"io"
+	"os"
+	"os/exec"
+	"strings"
+
+	"github.com/royalcat/ctxprogress"
+	"golang.org/x/sync/errgroup"
+)
+
+// Progress implements ctxprogress.Progress.
+func (p Entry) Progress() (current int, total int) {
+	return int(p.PlaylistIndex), int(p.PlaylistCount)
+}
+
+// func (p PlaylistEntry) Url() string {
+// 	if p.URL != "" {
+// 		return p.URL
+// 	}
+// 	if p.WebpageURL != "" {
+// 		return p.WebpageURL
+// 	}
+// 	if p.OriginalURL != "" {
+// 		return p.OriginalURL
+// 	}
+
+// 	return ""
+// }
+
+func (yt *Client) Playlist(ctx context.Context, url string) ([]Entry, error) {
+	group, ctx := errgroup.WithContext(ctx)
+	w, lines, err := lineReader(group)
+	if err != nil {
+		return nil, err
+	}
+
+	cmd := exec.CommandContext(ctx, yt.binary, "-j", url)
+
+	cmd.Stdout = w
+
+	group.Go(func() error {
+		err := cmd.Run()
+		if err != nil {
+			return err
+		}
+		return w.Close()
+	})
+
+	playlists := []Entry{}
+	for line := range lines {
+		entry := Entry{}
+		err = json.Unmarshal([]byte(line), &entry)
+		if err != nil {
+			return nil, err
+		}
+
+		playlists = append(playlists, entry)
+	}
+
+	return playlists, nil
+}
+
+func lineReader(group *errgroup.Group) (io.WriteCloser, <-chan string, error) {
+	lines := make(chan string)
+	var r io.Reader
+	r, w := io.Pipe()
+
+	r = io.TeeReader(r, os.Stdout)
+
+	group.Go(func() error {
+		defer close(lines)
+
+		reader := bufio.NewReader(r)
+		for {
+			line, err := reader.ReadString('\n')
+			if err != nil {
+				if err == io.EOF {
+					return w.Close()
+				}
+				return errors.Join(err, w.Close())
+			}
+			line = strings.Trim(line, " \r\t")
+
+			if line == "" {
+				continue
+			}
+
+			lines <- line
+		}
+	})
+
+	return w, lines, nil
+}
+
+var _ ctxprogress.Progress = (*Entry)(nil)
+
+var _ ctxprogress.Progress = (*DownloadProgress)(nil)
+
+func parseProgress(line string) (ctxprogress.Progress, error) {
+	line = strings.Trim(line, " \r\t")
+
+	p := &DownloadProgress{}
+	err := json.Unmarshal([]byte(line), p)
+	if err != nil {
+		return nil, err
+	}
+
+	return p, nil
+}