refactoring-1

introduced pipelines and abstracted download process.go in Downloader interface

server/internal/downloaders/common.go

@@ -0,0 +1,42 @@
+package downloaders
+
+import (
+	"log/slog"
+	"sync"
+
+	"github.com/marcopiovanello/yt-dlp-web-ui/v3/server/common"
+)
+
+type DownloaderBase struct {
+	Id        string
+	URL       string
+	Metadata  common.DownloadMetadata
+	Pending   bool
+	Completed bool
+	mutex     sync.Mutex
+}
+
+func (d *DownloaderBase) FetchMetadata(fetcher func(url string) (*common.DownloadMetadata, error)) {
+	d.mutex.Lock()
+	defer d.mutex.Unlock()
+
+	meta, err := fetcher(d.URL)
+	if err != nil {
+		slog.Error("failed to retrieve metadata", slog.Any("err", err))
+		return
+	}
+
+	d.Metadata = *meta
+}
+
+func (d *DownloaderBase) SetPending(p bool) {
+	d.mutex.Lock()
+	defer d.mutex.Unlock()
+	d.Pending = p
+}
+
+func (d *DownloaderBase) Complete() {
+	d.mutex.Lock()
+	defer d.mutex.Unlock()
+	d.Completed = true
+}