refactoring-1

introduced pipelines and abstracted download process.go in Downloader interface

server/playlist/playlist.go

@@ -0,0 +1,102 @@
+package playlist
+
+import (
+	"encoding/json"
+	"errors"
+	"log/slog"
+	"os/exec"
+	"slices"
+	"strings"
+	"time"
+
+	"github.com/marcopiovanello/yt-dlp-web-ui/v3/server/common"
+	"github.com/marcopiovanello/yt-dlp-web-ui/v3/server/config"
+	"github.com/marcopiovanello/yt-dlp-web-ui/v3/server/internal"
+	"github.com/marcopiovanello/yt-dlp-web-ui/v3/server/internal/downloaders"
+	"github.com/marcopiovanello/yt-dlp-web-ui/v3/server/internal/kv"
+	"github.com/marcopiovanello/yt-dlp-web-ui/v3/server/internal/queue"
+)
+
+func PlaylistDetect(req internal.DownloadRequest, mq *queue.MessageQueue, db *kv.Store) error {
+	params := append(req.Params, "--flat-playlist", "-J")
+	urlWithParams := append([]string{req.URL}, params...)
+
+	var (
+		downloader = config.Instance().DownloaderPath
+		cmd        = exec.Command(downloader, urlWithParams...)
+	)
+
+	stdout, err := cmd.StdoutPipe()
+	if err != nil {
+		return err
+	}
+
+	var m Metadata
+
+	if err := cmd.Start(); err != nil {
+		return err
+	}
+
+	slog.Info("decoding playlist metadata", slog.String("url", req.URL))
+
+	if err := json.NewDecoder(stdout).Decode(&m); err != nil {
+		return err
+	}
+
+	if err := cmd.Wait(); err != nil {
+		return err
+	}
+
+	slog.Info("decoded playlist metadata", slog.String("url", req.URL))
+
+	if m.Type == "" {
+		return errors.New("probably not a valid URL")
+	}
+
+	if m.IsPlaylist() {
+		entries := slices.CompactFunc(slices.Compact(m.Entries), func(a common.DownloadMetadata, b common.DownloadMetadata) bool {
+			return a.URL == b.URL
+		})
+
+		entries = slices.DeleteFunc(entries, func(e common.DownloadMetadata) bool {
+			return strings.Contains(e.URL, "list=")
+		})
+
+		slog.Info("playlist detected", slog.String("url", req.URL), slog.Int("count", len(entries)))
+
+		if err := ApplyModifiers(&entries, req.Params); err != nil {
+			return err
+		}
+
+		for i, meta := range entries {
+			// detect playlist title from metadata since each playlist entry will be
+			// treated as an individual download
+			req.Rename = strings.Replace(
+				req.Rename,
+				"%(playlist_title)s",
+				m.PlaylistTitle,
+				1,
+			)
+
+			//XXX: it's idiotic but it works: virtually delay the creation time
+			meta.CreatedAt = time.Now().Add(time.Millisecond * time.Duration(i*10))
+
+			downloader := downloaders.NewGenericDownload(meta.URL, req.Params)
+			downloader.SetOutput(internal.DownloadOutput{Filename: req.Rename})
+			// downloader.SetMetadata(meta)
+
+			db.Set(downloader)
+			mq.Publish(downloader)
+		}
+
+		return nil
+	}
+
+	d := downloaders.NewGenericDownload(req.URL, req.Params)
+
+	db.Set(d)
+	mq.Publish(d)
+	slog.Info("sending new process to message queue", slog.String("url", d.GetUrl()))
+
+	return cmd.Wait()
+}