refactor and to go mod

server/web/api/utils/link.go

@@ -0,0 +1,133 @@
+package utils
+
+import (
+	"errors"
+	"fmt"
+	"mime/multipart"
+	"net/http"
+	"net/url"
+	"runtime"
+	"strings"
+	"time"
+
+	"github.com/anacrolix/torrent"
+	"github.com/anacrolix/torrent/metainfo"
+)
+
+func ParseFile(file multipart.File) (*torrent.TorrentSpec, error) {
+	minfo, err := metainfo.Load(file)
+	if err != nil {
+		return nil, err
+	}
+	info, err := minfo.UnmarshalInfo()
+	if err != nil {
+		return nil, err
+	}
+
+	mag := minfo.Magnet(info.Name, minfo.HashInfoBytes())
+	return &torrent.TorrentSpec{
+		InfoBytes:   minfo.InfoBytes,
+		Trackers:    [][]string{mag.Trackers},
+		DisplayName: info.Name,
+		InfoHash:    minfo.HashInfoBytes(),
+	}, nil
+}
+
+func ParseLink(link string) (*torrent.TorrentSpec, error) {
+	urlLink, err := url.Parse(link)
+	if err != nil {
+		return nil, err
+	}
+
+	switch strings.ToLower(urlLink.Scheme) {
+	case "magnet":
+		return fromMagnet(urlLink.String())
+	case "http", "https":
+		return fromHttp(urlLink.String())
+	case "":
+		return fromMagnet("magnet:?xt=urn:btih:" + urlLink.Path)
+	case "file":
+		return fromFile(urlLink.Path)
+	default:
+		err = fmt.Errorf("unknown scheme:", urlLink, urlLink.Scheme)
+	}
+	return nil, err
+}
+
+func fromMagnet(link string) (*torrent.TorrentSpec, error) {
+	mag, err := metainfo.ParseMagnetUri(link)
+	if err != nil {
+		return nil, err
+	}
+
+	var trackers [][]string
+	if len(mag.Trackers) > 0 {
+		trackers = [][]string{mag.Trackers}
+	}
+
+	return &torrent.TorrentSpec{
+		InfoBytes:   nil,
+		Trackers:    trackers,
+		DisplayName: mag.DisplayName,
+		InfoHash:    mag.InfoHash,
+	}, nil
+}
+
+func fromHttp(url string) (*torrent.TorrentSpec, error) {
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	client := new(http.Client)
+	client.Timeout = time.Duration(time.Second * 30)
+	req.Header.Set("User-Agent", "DWL/1.1.1 (Torrent)")
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != 200 {
+		return nil, errors.New(resp.Status)
+	}
+
+	minfo, err := metainfo.Load(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+	info, err := minfo.UnmarshalInfo()
+	if err != nil {
+		return nil, err
+	}
+	mag := minfo.Magnet(info.Name, minfo.HashInfoBytes())
+
+	return &torrent.TorrentSpec{
+		InfoBytes:   minfo.InfoBytes,
+		Trackers:    [][]string{mag.Trackers},
+		DisplayName: info.Name,
+		InfoHash:    minfo.HashInfoBytes(),
+	}, nil
+}
+
+func fromFile(path string) (*torrent.TorrentSpec, error) {
+	if runtime.GOOS == "windows" && strings.HasPrefix(path, "/") {
+		path = strings.TrimPrefix(path, "/")
+	}
+	minfo, err := metainfo.LoadFromFile(path)
+	if err != nil {
+		return nil, err
+	}
+	info, err := minfo.UnmarshalInfo()
+	if err != nil {
+		return nil, err
+	}
+
+	mag := minfo.Magnet(info.Name, minfo.HashInfoBytes())
+	return &torrent.TorrentSpec{
+		InfoBytes:   minfo.InfoBytes,
+		Trackers:    [][]string{mag.Trackers},
+		DisplayName: info.Name,
+		InfoHash:    minfo.HashInfoBytes(),
+	}, nil
+}