Fix proxied download by removing approx filesize

.air.toml

@@ -3,7 +3,7 @@ testdata_dir = "testdata"
 tmp_dir = "tmp"
 
 [build]
-args_bin = ["-l", "0.0.0.0"]
+args_bin = ["-l", "0.0.0.0", "-p", "3000"]
 bin = "./out/ytdl-web"
 cmd = "build"
 delay = 1000

app/controllers/download.go

@@ -2,8 +2,10 @@ package controllers
 
 import (
 	"fmt"
+	"io"
 	"net/http"
 	"net/url"
+	"sync"
 
 	"github.com/go-chi/chi/v5"
 	"github.com/samber/lo"
@@ -147,17 +149,39 @@ func (c *DownloadController) ProxyDownload(w http.ResponseWriter, r *http.Reques
 	w.Header().Set("Content-Disposition", fmt.Sprintf("attachment; filename=\"%s-%s.%s\"", meta.ID, format.Resolution, format.Ext))
 	if format.Filesize != nil {
 		w.Header().Set("Content-Length", fmt.Sprint(*format.Filesize))
-	} else if format.FilesizeApprox != nil {
-		w.Header().Set("Content-Length", fmt.Sprint(*format.FilesizeApprox))
 	}
 
 	if len(videos) == 1 {
 		index = -1
 	}
 
-	if err := c.ytdl.Download(w, videoUrl, format.FormatID, index); err != nil {
-		slog.Error("Failed to download", slog.String("error", err.Error()))
-		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
-		return
-	}
+	pread, pwrite := io.Pipe()
+	var wg sync.WaitGroup
+	wg.Add(2)
+
+	go func() {
+		defer wg.Done()
+
+		if err := c.ytdl.Download(pwrite, videoUrl, format.FormatID, index); err != nil {
+			slog.Error("Failed to download", slog.String("error", err.Error()))
+			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+			pwrite.CloseWithError(err)
+			return
+		} else {
+			pwrite.Close()
+		}
+	}()
+
+	go func() {
+		defer wg.Done()
+
+		_, err = io.Copy(w, pread)
+		if err != nil {
+			slog.Error("Failed to copy", slog.String("error", err.Error()))
+			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+			return
+		}
+	}()
+
+	wg.Wait()
 }