refactor handler out

src/cmd/server/handler/vpntor.go

@@ -0,0 +1,65 @@
+package handler
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"time"
+)
+
+func (h Handler) vpntor(ctx context.Context, r io.Reader) error {
+	var form struct {
+		Magnet string
+		Dir    string
+		URL    string
+	}
+	if err := json.NewDecoder(r).Decode(&form); err != nil {
+		return err
+	}
+	if form.Magnet == "" || form.Dir == "" || form.URL == "" {
+		return fmt.Errorf("did not specify all of .Magnet, .Dir, .URL")
+	}
+
+	c := http.Client{
+		Timeout:   time.Minute,
+		Transport: &http.Transport{DisableKeepAlives: true},
+	}
+	sresp, err := c.Get(form.URL)
+	if err != nil {
+		return err
+	}
+	defer sresp.Body.Close()
+	defer io.Copy(io.Discard, sresp.Body)
+
+	b, _ := json.Marshal(map[string]any{
+		"method": "torrent-add",
+		"arguments": map[string]string{
+			"filename":     form.Magnet,
+			"download-dir": form.Dir,
+		},
+	})
+
+	req, err := http.NewRequest(http.MethodPost, form.URL, bytes.NewReader(b))
+	if err != nil {
+		return err
+	}
+	req = req.WithContext(ctx)
+	req.Header.Add("X-Transmission-Session-Id", sresp.Header.Get("X-Transmission-Session-Id"))
+
+	resp, err := c.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	defer io.Copy(io.Discard, resp.Body)
+
+	if b, _ := ioutil.ReadAll(resp.Body); resp.StatusCode > 220 || !bytes.Contains(b, []byte(`success`)) {
+		return fmt.Errorf("(%d) %s", resp.StatusCode, b)
+	}
+
+	return nil
+}