From 8052c02af11fe4b95adc7c79def98fb8370a0822 Mon Sep 17 00:00:00 2001
From: Evan Fiordeliso <evan.fiordeliso@gmail.com>
Date: Tue, 23 May 2023 19:35:52 -0400
Subject: [PATCH] Fix proxy endpoint for playlists

---
 web/formats.go            |  2 +-
 web/routes.go             | 16 ++++++++++++++--
 web/views/download.html   | 16 +---------------
 ytdl/cmdopts.go           |  8 ++++++++
 ytdl/metadata/metadata.go |  4 ++++
 ytdl/ytdl.go              |  8 ++++++--
 6 files changed, 34 insertions(+), 20 deletions(-)

diff --git a/web/formats.go b/web/formats.go
index b1d8342..007f6e1 100644
--- a/web/formats.go
+++ b/web/formats.go
@@ -11,7 +11,7 @@ type Video struct {
 }
 
 func GetVideos(meta *metadata.Metadata) []Video {
-	if meta.Type == "playlist" {
+	if meta.IsPlaylist() {
 		return lo.Map(meta.Entries, func(video metadata.Metadata, _ int) Video {
 			return GetVideos(&video)[0]
 		})
diff --git a/web/routes.go b/web/routes.go
index 7f7f19e..d737e24 100644
--- a/web/routes.go
+++ b/web/routes.go
@@ -92,7 +92,15 @@ func (r *routes) DownloadProxyHandler(c *fiber.Ctx) error {
 		return fiber.ErrInternalServerError
 	}
 
-	format, ok := lo.Find(meta.Formats, func(format metadata.Format) bool {
+	videos := GetVideos(meta)
+	index := c.QueryInt("index")
+
+	if index < 0 || index >= len(videos) {
+		return fiber.ErrBadRequest
+	}
+
+	video := videos[index]
+	format, ok := lo.Find(video.Formats, func(format metadata.Format) bool {
 		return format.FormatID == formatId
 	})
 	if !ok {
@@ -106,5 +114,9 @@ func (r *routes) DownloadProxyHandler(c *fiber.Ctx) error {
 		c.Set("Content-Length", fmt.Sprint(*format.FilesizeApprox))
 	}
 
-	return r.ytdl.Download(c.Response().BodyWriter(), url, format.FormatID)
+	if len(videos) == 1 {
+		index = -1
+	}
+
+	return r.ytdl.Download(c.Response().BodyWriter(), url, format.FormatID, index)
 }
diff --git a/web/views/download.html b/web/views/download.html
index f9da057..a55660c 100644
--- a/web/views/download.html
+++ b/web/views/download.html
@@ -9,20 +9,6 @@
 
 {{$root := .}}
 
-{{define "download"}}
-<div style="font-size: smaller">{{.Format.Format}}</div>
-<div class="flex-grow-1 d-flex gap-3">
-  <a class="btn btn-primary flex-grow-1" download="{{.Meta.ID}}-{{.Format.Resolution}}.{{.Format.Ext}}" P
-    href="{{.Format.Url}}">
-    Download (direct)
-  </a>
-  <a class="btn btn-primary flex-grow-1" download="{{.Meta.ID}}-{{.Format.Resolution}}.{{.Format.Ext}}"
-    href="{{.BasePath}}/download/proxy?url={{queryEscape .Url}}&format={{.Format.FormatID}}">
-    Download (proxied)
-  </a>
-</div>
-{{end}}
-
 {{range $vidIndex, $video := .Videos}}
 {{if not (eq $vidIndex 0)}}
 <hr class="mt-5" />
@@ -40,7 +26,7 @@
         Download (direct)
       </a>
       <a class="btn btn-primary flex-grow-1" download="{{$root.Meta.ID}}-{{$format.Resolution}}.{{$format.Ext}}"
-        href="{{$root.BasePath}}/download/proxy?url={{queryEscape $root.Url}}&format={{$format.FormatID}}">
+        href="{{$root.BasePath}}/download/proxy?url={{queryEscape $root.Url}}&format={{$format.FormatID}}&index={{$vidIndex}}">
         Download (proxied)
       </a>
     </div>
diff --git a/ytdl/cmdopts.go b/ytdl/cmdopts.go
index 5080bd0..314f7ac 100644
--- a/ytdl/cmdopts.go
+++ b/ytdl/cmdopts.go
@@ -3,6 +3,7 @@ package ytdl
 import (
 	"bytes"
 	"encoding/json"
+	"fmt"
 	"io"
 	"strings"
 
@@ -99,3 +100,10 @@ func WithDebug() Option {
 		return nil
 	}
 }
+
+func WithPlaylistIndex(index int) Option {
+	return func(opts *Options) error {
+		opts.args = append(opts.args, "--playlist-items", fmt.Sprint(index+1))
+		return nil
+	}
+}
diff --git a/ytdl/metadata/metadata.go b/ytdl/metadata/metadata.go
index 3e4bac0..9545ed6 100644
--- a/ytdl/metadata/metadata.go
+++ b/ytdl/metadata/metadata.go
@@ -176,3 +176,7 @@ type Metadata struct {
 
 	Chapters []Chapter `json:"chapters"`
 }
+
+func (m Metadata) IsPlaylist() bool {
+	return m.Type == "playlist"
+}
diff --git a/ytdl/ytdl.go b/ytdl/ytdl.go
index 310017d..1404304 100644
--- a/ytdl/ytdl.go
+++ b/ytdl/ytdl.go
@@ -11,7 +11,7 @@ import (
 
 type Ytdl interface {
 	GetMetadata(url string) (*metadata.Metadata, error)
-	Download(w io.Writer, url, format string) error
+	Download(w io.Writer, url, format string, index int) error
 }
 
 type ytdlImpl struct {
@@ -82,13 +82,17 @@ func (y *ytdlImpl) GetMetadata(url string) (*metadata.Metadata, error) {
 }
 
 // Download implements Ytdl
-func (y *ytdlImpl) Download(w io.Writer, url, format string) error {
+func (y *ytdlImpl) Download(w io.Writer, url, format string, index int) error {
 	options := append(
 		y.baseOptions(url),
 		WithFormat(format),
 		WithStreamOutput(w),
 	)
 
+	if index >= 0 {
+		options = append(options, WithPlaylistIndex(index))
+	}
+
 	if err := Exec(y.cfg.Ytdlp.BinaryPath, url, options...); err != nil {
 		return err
 	}