get the proper magnet and infohash for upload

router/upload.go

@@ -1,17 +1,22 @@
 package router
 
 import (
+	"encoding/hex"
 	"errors"
+	"fmt"
 	"github.com/ewhal/nyaa/util"
 	"github.com/ewhal/nyaa/util/metainfo"
 	"github.com/zeebo/bencode"
 	"net/http"
+	"net/url"
+	"strings"
 )
 
 // UploadForm serializing HTTP form for torrent upload
 type UploadForm struct {
 	Name        string
 	Magnet      string
+	Infohash    string
 	Category    string
 	Description string
 }
@@ -85,8 +90,23 @@ func (f *UploadForm) ExtractInfo(r *http.Request) error {
 		}
 
 		// generate magnet
-		f.Magnet = util.InfoHashToMagnet(torrent.Infohash(), f.Name)
+		binInfoHash := torrent.Infohash()
+		f.Infohash = hex.EncodeToString(binInfoHash[:])
+		f.Magnet = util.InfoHashToMagnet(f.Infohash, f.Name)
+	} else {
+		magnetUrl, parseErr := url.Parse(f.Magnet)
+		if parseErr != nil {
+			return metainfo.ErrInvalidTorrentFile
+		}
+		fmt.Println(magnetUrl)
+		exactTopic := magnetUrl.Query().Get("xt")
+		if !strings.HasPrefix(exactTopic, "urn:btih:") {
+			return metainfo.ErrInvalidTorrentFile
+		} else {
+			f.Infohash = strings.ToUpper(strings.TrimPrefix(exactTopic, "urn:btih:"))
+		}
 	}
+
 	return nil
 }
 

util/magnet.go

@@ -1,15 +1,13 @@
 package util
 
 import (
-	"encoding/hex"
 	"fmt"
 	"net/url"
 )
 
 // convert a binary infohash to a magnet uri given a display name and tracker urls
-func InfoHashToMagnet(ih [20]byte, name string, trackers ...url.URL) (str string) {
-	str = hex.EncodeToString(ih[:])
-	str = fmt.Sprintf("magnet:?xt=urn:btih:%s", str)
+func InfoHashToMagnet(ih string, name string, trackers ...url.URL) (str string) {
+	str = fmt.Sprintf("magnet:?xt=urn:btih:%s", ih)
 	if len(name) > 0 {
 		str += fmt.Sprintf("&dn=%s", name)
 	}