From 026c73788652bc822ce25782690f2296c4ba5c1f Mon Sep 17 00:00:00 2001
From: Matt Joiner <anacrolix@gmail.com>
Date: Tue, 2 Jun 2020 13:53:25 +1000
Subject: [PATCH] Add webseeds from magnet links

---
 client.go | 10 ++++------
 spec.go   | 37 ++++++++++++++++++++++++-------------
 2 files changed, 28 insertions(+), 19 deletions(-)

diff --git a/client.go b/client.go
index 9861f7ef..96a37c02 100644
--- a/client.go
+++ b/client.go
@@ -1155,8 +1155,12 @@ func (cl *Client) AddTorrentSpec(spec *TorrentSpec) (t *Torrent, new bool, err e
 			return
 		}
 	}
+	cl.AddDHTNodes(spec.DhtNodes)
 	cl.lock()
 	defer cl.unlock()
+	for _, url := range spec.Webseeds {
+		t.addWebSeed(url)
+	}
 	if spec.ChunkSize != 0 {
 		t.setChunkSize(pp.Integer(spec.ChunkSize))
 	}
@@ -1230,12 +1234,6 @@ func (cl *Client) AddMagnet(uri string) (T *Torrent, err error) {
 
 func (cl *Client) AddTorrent(mi *metainfo.MetaInfo) (T *Torrent, err error) {
 	T, _, err = cl.AddTorrentSpec(TorrentSpecFromMetaInfo(mi))
-	var ss []string
-	slices.MakeInto(&ss, mi.Nodes)
-	cl.AddDHTNodes(ss)
-	for _, url := range mi.UrlList {
-		T.addWebSeed(url)
-	}
 	return
 }
 
diff --git a/spec.go b/spec.go
index 5dbd472b..e0c13bd8 100644
--- a/spec.go
+++ b/spec.go
@@ -5,8 +5,8 @@ import (
 	"github.com/anacrolix/torrent/storage"
 )
 
-// Specifies a new torrent for adding to a client. There are helpers for
-// magnet URIs and torrent metainfo files.
+// Specifies a new torrent for adding to a client. There are helpers for magnet URIs and torrent
+// metainfo files.
 type TorrentSpec struct {
 	// The tiered tracker URIs.
 	Trackers  [][]string
@@ -14,8 +14,10 @@ type TorrentSpec struct {
 	InfoBytes []byte
 	// The name to use if the Name field from the Info isn't available.
 	DisplayName string
-	// The chunk size to use for outbound requests. Defaults to 16KiB if not
-	// set.
+	Webseeds    []string
+	DhtNodes    []string
+
+	// The chunk size to use for outbound requests. Defaults to 16KiB if not set.
 	ChunkSize int
 	Storage   storage.ClientImpl
 }
@@ -29,20 +31,29 @@ func TorrentSpecFromMagnetURI(uri string) (spec *TorrentSpec, err error) {
 		Trackers:    [][]string{m.Trackers},
 		DisplayName: m.DisplayName,
 		InfoHash:    m.InfoHash,
+		Webseeds:    m.Params["ws"],
+		// TODO: What's the parameter for DHT nodes or bootstrap peers in a magnet link?
 	}
 	return
 }
 
-func TorrentSpecFromMetaInfo(mi *metainfo.MetaInfo) (spec *TorrentSpec) {
-	info, _ := mi.UnmarshalInfo()
-	spec = &TorrentSpec{
-		Trackers:    mi.AnnounceList,
+func TorrentSpecFromMetaInfo(mi *metainfo.MetaInfo) *TorrentSpec {
+	info, err := mi.UnmarshalInfo()
+	if err != nil {
+		panic(err)
+	}
+	return &TorrentSpec{
+		Trackers:    mi.UpvertedAnnounceList(),
+		InfoHash:    mi.HashInfoBytes(),
 		InfoBytes:   mi.InfoBytes,
 		DisplayName: info.Name,
-		InfoHash:    mi.HashInfoBytes(),
+		Webseeds:    mi.UrlList,
+		DhtNodes: func() (ret []string) {
+			ret = make([]string, len(mi.Nodes))
+			for _, node := range mi.Nodes {
+				ret = append(ret, string(node))
+			}
+			return
+		}(),
 	}
-	if spec.Trackers == nil && mi.Announce != "" {
-		spec.Trackers = [][]string{{mi.Announce}}
-	}
-	return
 }
-- 
2.44.0