WIP: buildin torrent client

pkg/buildin/torrent.go

@@ -0,0 +1,145 @@
+package buildin
+
+import (
+	"fmt"
+	"github.com/anacrolix/torrent"
+	"github.com/anacrolix/torrent/metainfo"
+	"github.com/pkg/errors"
+	"io/fs"
+	"net/http"
+	"os"
+	"polaris/pkg"
+	"strings"
+)
+
+type Downloader struct {
+	cl *torrent.Client
+}
+
+func (d *Downloader) GetAll() ([]pkg.Torrent, error) {
+	ts := d.cl.Torrents()
+	var res []pkg.Torrent
+	for _, t := range ts {
+		res = append(res, &Torrent{
+			t:  t,
+			cl: d.cl,
+		})
+	}
+	return res, nil
+}
+
+func (d *Downloader) Download(link, hash, dir string) (pkg.Torrent, error) {
+
+	if strings.HasPrefix(strings.ToLower(link), "magnet:") {
+		t, err := d.cl.AddMagnet(link)
+		if err != nil {
+			return nil, fmt.Errorf("failed to add magnet: %v", err)
+		}
+		return &Torrent{
+			t:    t,
+			cl:   d.cl,
+			hash: hash,
+		}, nil
+	}
+	client := &http.Client{
+		CheckRedirect: func(req *http.Request, via []*http.Request) error {
+			return http.ErrUseLastResponse //do not follow redirects
+		},
+	}
+
+	resp, err := client.Get(link)
+	if err != nil {
+		return nil, errors.Wrap(err, "get link")
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode >= 300 && resp.StatusCode < 400 {
+		//redirects
+		tourl := resp.Header.Get("Location")
+		return d.Download(tourl, hash, dir)
+	}
+	info, err := metainfo.Load(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("failed to load metainfo: %v", err)
+	}
+	t, err := d.cl.AddTorrent(info)
+	if err != nil {
+		return nil, fmt.Errorf("failed to add torrent: %v", err)
+	}
+	return &Torrent{
+		t:    t,
+		cl:   d.cl,
+		hash: hash,
+	}, nil
+}
+
+type Torrent struct {
+	t    *torrent.Torrent
+	cl   *torrent.Client
+	hash string
+}
+
+func (t *Torrent) Name() (string, error) {
+	return t.t.Name(), nil
+}
+
+func (t *Torrent) TotalSize() int64 {
+	var c int64
+	for _, f := range t.t.Files() {
+		c += f.FileInfo().Length
+	}
+	return c
+}
+
+func (t *Torrent) Progress() (int, error) {
+	if t.t.Complete().Bool() {
+		return 100, nil
+	}
+	return int(t.t.BytesCompleted() * 100 / t.TotalSize()), nil
+}
+
+func (t *Torrent) Stop() error {
+	return nil
+}
+
+func (t *Torrent) Start() error {
+	<-t.t.GotInfo()
+	t.t.DownloadAll()
+	return nil
+}
+
+func (t *Torrent) Remove() error {
+	t.t.Drop()
+	return nil
+}
+
+func (t *Torrent) Exists() bool {
+	return true
+}
+
+func (t *Torrent) SeedRatio() (float64, error) {
+	return 0, nil
+}
+
+func (t *Torrent) GetHash() string {
+	return t.hash
+}
+
+func (t *Torrent) WalkFunc() func(fn func(path string, info fs.FileInfo) error) error {
+	files := t.t.Files()
+
+	return func(fn func(path string, info fs.FileInfo) error) error {
+		for _, file := range files {
+			name := file.Path()
+			info, err := os.Stat(name)
+			if err != nil {
+				return err
+			}
+
+			if err := fn(name, info); err != nil {
+				return errors.Errorf("proccess file (%s) error: %v", file.Path(), err)
+			}
+		}
+		return nil
+
+	}
+}