init: pristine aerc 0.20.0 source

commands/msg/unsubscribe.go

@@ -0,0 +1,202 @@
+package msg
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"net/url"
+	"strings"
+	"time"
+
+	"git.sr.ht/~rjarry/aerc/app"
+	"git.sr.ht/~rjarry/aerc/commands"
+	"git.sr.ht/~rjarry/aerc/config"
+	"git.sr.ht/~rjarry/aerc/lib"
+	"git.sr.ht/~rjarry/aerc/lib/log"
+	"github.com/emersion/go-message/mail"
+)
+
+// Unsubscribe helps people unsubscribe from mailing lists by way of the
+// List-Unsubscribe header.
+type Unsubscribe struct {
+	Edit       bool `opt:"-e" desc:"Force [compose].edit-headers = true."`
+	NoEdit     bool `opt:"-E" desc:"Force [compose].edit-headers = false."`
+	SkipEditor bool `opt:"-s" desc:"Skip the editor and go directly to the review screen."`
+}
+
+func init() {
+	commands.Register(Unsubscribe{})
+}
+
+func (Unsubscribe) Description() string {
+	return "Attempt to automatically unsubscribe from mailing lists."
+}
+
+func (Unsubscribe) Context() commands.CommandContext {
+	return commands.MESSAGE_LIST | commands.MESSAGE_VIEWER
+}
+
+// Aliases returns a list of aliases for the :unsubscribe command
+func (Unsubscribe) Aliases() []string {
+	return []string{"unsubscribe"}
+}
+
+// Execute runs the Unsubscribe command
+func (u Unsubscribe) Execute(args []string) error {
+	editHeaders := (config.Compose.EditHeaders || u.Edit) && !u.NoEdit
+
+	widget := app.SelectedTabContent().(app.ProvidesMessage)
+	msg, err := widget.SelectedMessage()
+	if err != nil {
+		return err
+	}
+	headers := msg.RFC822Headers
+	if !headers.Has("list-unsubscribe") {
+		return errors.New("No List-Unsubscribe header found")
+	}
+	text, err := headers.Text("list-unsubscribe")
+	if err != nil {
+		return err
+	}
+	methods := parseUnsubscribeMethods(text)
+	if len(methods) == 0 {
+		return fmt.Errorf("no methods found to unsubscribe")
+	}
+	log.Debugf("unsubscribe: found %d methods", len(methods))
+
+	unsubscribe := func(method *url.URL) {
+		log.Debugf("unsubscribe: trying to unsubscribe using %s", method.Scheme)
+		var err error
+		switch strings.ToLower(method.Scheme) {
+		case "mailto":
+			err = unsubscribeMailto(method, editHeaders, u.SkipEditor)
+		case "http", "https":
+			err = unsubscribeHTTP(method)
+		default:
+			err = fmt.Errorf("unsubscribe: skipping unrecognized scheme: %s", method.Scheme)
+		}
+		if err != nil {
+			app.PushError(err.Error())
+		}
+	}
+
+	var title string = "Select method to unsubscribe"
+	if msg != nil && msg.Envelope != nil && len(msg.Envelope.From) > 0 {
+		title = fmt.Sprintf("%s from %s", title, msg.Envelope.From[0])
+	}
+
+	options := make([]string, len(methods))
+	for i, method := range methods {
+		options[i] = method.Scheme
+	}
+
+	dialog := app.NewSelectorDialog(
+		title,
+		"Press <Enter> to confirm or <ESC> to cancel",
+		options, 0, app.SelectedAccountUiConfig(),
+		func(option string, err error) {
+			app.CloseDialog()
+			if err != nil {
+				if errors.Is(err, app.ErrNoOptionSelected) {
+					app.PushStatus("Unsubscribe: "+err.Error(),
+						5*time.Second)
+				} else {
+					app.PushError("Unsubscribe: " + err.Error())
+				}
+				return
+			}
+			for _, m := range methods {
+				if m.Scheme == option {
+					unsubscribe(m)
+					return
+				}
+			}
+			app.PushError("Unsubscribe: selected method not found")
+		},
+	)
+	app.AddDialog(dialog)
+
+	return nil
+}
+
+// parseUnsubscribeMethods reads the list-unsubscribe header and parses it as a
+// list of angle-bracket <> deliminated URLs. See RFC 2369.
+func parseUnsubscribeMethods(header string) (methods []*url.URL) {
+	r := bufio.NewReader(strings.NewReader(header))
+	for {
+		// discard until <
+		_, err := r.ReadSlice('<')
+		if err != nil {
+			return
+		}
+		// read until <
+		m, err := r.ReadSlice('>')
+		if err != nil {
+			return
+		}
+		m = m[:len(m)-1]
+		if u, err := url.Parse(string(m)); err == nil {
+			methods = append(methods, u)
+		}
+	}
+}
+
+func unsubscribeMailto(u *url.URL, editHeaders, skipEditor bool) error {
+	widget := app.SelectedTabContent().(app.ProvidesMessage)
+	acct := widget.SelectedAccount()
+	if acct == nil {
+		return errors.New("No account selected")
+	}
+
+	h := &mail.Header{}
+	h.SetSubject(u.Query().Get("subject"))
+	if to, err := mail.ParseAddressList(u.Opaque); err == nil {
+		h.SetAddressList("to", to)
+	}
+
+	composer, err := app.NewComposer(
+		acct,
+		acct.AccountConfig(),
+		acct.Worker(),
+		editHeaders,
+		"",
+		h,
+		nil,
+		strings.NewReader(u.Query().Get("body")),
+	)
+	if err != nil {
+		return err
+	}
+	composer.Tab = app.NewTab(composer, "unsubscribe")
+	if skipEditor {
+		composer.Terminal().Close()
+	} else {
+		composer.FocusTerminal()
+	}
+	return nil
+}
+
+func unsubscribeHTTP(u *url.URL) error {
+	confirm := app.NewSelectorDialog(
+		"Do you want to open this link?",
+		u.String(),
+		[]string{"No", "Yes"}, 0, app.SelectedAccountUiConfig(),
+		func(option string, _ error) {
+			app.CloseDialog()
+			switch option {
+			case "Yes":
+				go func() {
+					defer log.PanicHandler()
+					mime := fmt.Sprintf("x-scheme-handler/%s", u.Scheme)
+					if err := lib.XDGOpenMime(u.String(), mime, ""); err != nil {
+						app.PushError("Unsubscribe:" + err.Error())
+					}
+				}()
+			default:
+				app.PushError("Unsubscribe: link will not be opened")
+			}
+		},
+	)
+	app.AddDialog(confirm)
+	return nil
+}