From 8dc7615432e0b9611238f70562e660e5da7fbd21 Mon Sep 17 00:00:00 2001
From: Matt Joiner <anacrolix@gmail.com>
Date: Mon, 25 Mar 2024 13:32:46 +1100
Subject: [PATCH] cmd/torrent metainfo magnet: Support v2 torrents

---
 cmd/torrent/metainfo.go |  4 ++--
 metainfo/metainfo.go    | 23 ++++++++++++++++++++++-
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/cmd/torrent/metainfo.go b/cmd/torrent/metainfo.go
index dd9d399c..1a940fc5 100644
--- a/cmd/torrent/metainfo.go
+++ b/cmd/torrent/metainfo.go
@@ -49,11 +49,11 @@ func metainfoCmd() (cmd bargle.Command) {
 		},
 		bargle.Subcommand{Name: "magnet", Command: func() (cmd bargle.Command) {
 			cmd.DefaultAction = func() (err error) {
-				info, err := mi.UnmarshalInfo()
+				m, err := mi.MagnetV2()
 				if err != nil {
 					return
 				}
-				fmt.Fprintf(os.Stdout, "%s\n", mi.Magnet(nil, &info).String())
+				fmt.Fprintf(os.Stdout, "%v\n", m.String())
 				return nil
 			}
 			return
diff --git a/metainfo/metainfo.go b/metainfo/metainfo.go
index 6a5ea1cd..383b5ca9 100644
--- a/metainfo/metainfo.go
+++ b/metainfo/metainfo.go
@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"github.com/anacrolix/torrent/bencode"
+	infohash_v2 "github.com/anacrolix/torrent/types/infohash-v2"
 )
 
 // Also known as a torrent file.
@@ -72,7 +73,8 @@ func (mi *MetaInfo) SetDefaults() {
 	mi.CreationDate = time.Now().Unix()
 }
 
-// Creates a Magnet from a MetaInfo. Optional infohash and parsed info can be provided.
+// Deprecated: Use MagnetV2. Creates a Magnet from a MetaInfo. Optional infohash and parsed info can
+// be provided.
 func (mi MetaInfo) Magnet(infoHash *Hash, info *Info) (m Magnet) {
 	m.Trackers = append(m.Trackers, mi.UpvertedAnnounceList().DistinctValues()...)
 	if info != nil {
@@ -88,6 +90,25 @@ func (mi MetaInfo) Magnet(infoHash *Hash, info *Info) (m Magnet) {
 	return
 }
 
+// Creates a MagnetV2 from a MetaInfo. This supports v1, hybrid, and v2 magnet links.
+func (mi *MetaInfo) MagnetV2() (m MagnetV2, err error) {
+	m.Trackers = append(m.Trackers, mi.UpvertedAnnounceList().DistinctValues()...)
+	info, err := mi.UnmarshalInfo()
+	if err != nil {
+		return
+	}
+	m.DisplayName = info.BestName()
+	if info.HasV1() {
+		m.InfoHash.Set(mi.HashInfoBytes())
+	}
+	if info.HasV2() {
+		m.V2InfoHash.Set(infohash_v2.HashBytes(mi.InfoBytes))
+	}
+	m.Params = make(url.Values)
+	m.Params["ws"] = mi.UrlList
+	return
+}
+
 // Returns the announce-list converted from the old single announce field if necessary.
 func (mi *MetaInfo) UpvertedAnnounceList() AnnounceList {
 	if mi.AnnounceList.OverridesAnnounce(mi.Announce) {
-- 
2.48.1