small refactor*

server/pkg/ytdlp/download.go

@@ -0,0 +1,105 @@
+package ytdlp
+
+import (
+	"context"
+	"encoding/json"
+	"io"
+	"os/exec"
+	"strings"
+
+	"github.com/royalcat/ctxprogress"
+	"golang.org/x/sync/errgroup"
+)
+
+type DownloadStatus string
+
+const (
+	StatusDownloading DownloadStatus = "downloading"
+	StatusFinished    DownloadStatus = "finished"
+	StatusErrored     DownloadStatus = "error"
+)
+
+// Progress for the Running call
+type DownloadProgress struct {
+	Status             DownloadStatus `json:"status"`
+	Filename           string         `json:"filename"`
+	TmpFilename        string         `json:"tmpfilename"`
+	DownloadedBytes    int64          `json:"downloaded_bytes"`
+	TotalBytes         int64          `json:"total_bytes"`
+	TotalBytesEstimate float64        `json:"total_bytes_estimate"`
+	Elapsed            float64        `json:"elapsed"`
+	ETA                float64        `json:"eta"`
+	Speed              float64        `json:"speed"`
+	FragmentIndex      int64          `json:"fragment_index"`
+	FragmentCount      int64          `json:"fragment_count"`
+}
+
+// Current implements ctxprogress.Progress.
+func (d DownloadProgress) Progress() (int, int) {
+	if d.TotalBytes != -1 && d.TotalBytes != 0 && d.DownloadedBytes != -1 {
+		return int(d.DownloadedBytes), int(d.TotalBytes)
+	}
+
+	if d.TotalBytesEstimate != -1 && d.TotalBytesEstimate != 0 && d.DownloadedBytes != -1 {
+		return int(d.DownloadedBytes), int(d.TotalBytesEstimate)
+	}
+
+	return int(d.FragmentIndex), int(d.FragmentCount)
+}
+
+const rawProgressTemplate = `download:
+%{
+	"status":"%(progress.status)s",
+	"eta":%(progress.eta|-1)s,
+	"speed":%(progress.speed|0)s,
+	"downloaded_bytes":%(progress.downloaded_bytes|-1)s,
+	"total_bytes": %(progress.total_bytes|-1)s,
+	"total_bytes_estimate": %(progress.total_bytes_estimate|-1)s,
+	"fragment_index":%(progress.fragment_index|-1)s,
+	"fragment_count":%(progress.fragment_count|-1)s
+}`
+
+var progressTemplate = strings.NewReplacer("\n", "", "\t", "", " ", "").Replace(rawProgressTemplate)
+
+func (c *Client) Download(ctx context.Context, url string, w io.Writer) error {
+	args := []string{
+		"--progress", "--newline", "--progress-template", progressTemplate,
+		"-o", "-",
+		url,
+	}
+
+	group, ctx := errgroup.WithContext(ctx)
+
+	stderr, lines, err := lineReader(group)
+	if err != nil {
+		return err
+	}
+	cmd := exec.CommandContext(ctx, c.binary, args...)
+
+	cmd.Stdout = w
+	cmd.Stderr = stderr
+
+	group.Go(func() error {
+		err := cmd.Run()
+		stderr.Close()
+		if err != nil {
+			return err
+		}
+		return nil
+	})
+
+	for line := range lines {
+		if line, ok := strings.CutPrefix(line, "%"); ok {
+			p := DownloadProgress{}
+			err = json.Unmarshal([]byte(line), &p)
+			if err != nil {
+				//TODO: handle error
+				continue
+			}
+
+			ctxprogress.Set(ctx, p)
+		}
+	}
+
+	return group.Wait()
+}