add group preview subcommand

cmd/signaldctl/cmd/group/preview/preview.go

@@ -0,0 +1,78 @@
+// Copyright © 2021 Finn Herzfeld <finn@janky.solutions>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+package preview
+
+import (
+	"encoding/json"
+	"errors"
+	"log"
+	"os"
+	"strings"
+
+	"github.com/spf13/cobra"
+
+	"gitlab.com/signald/signald-go/cmd/signaldctl/common"
+	"gitlab.com/signald/signald-go/cmd/signaldctl/config"
+	"gitlab.com/signald/signald-go/signald/client-protocol/v1"
+)
+
+var (
+	account         string
+	joinURL         string
+	PreviewGroupCmd = &cobra.Command{
+		Use:   "preview https://signal.group/...",
+		Short: "preview information about a group without joining",
+		PreRunE: func(cmd *cobra.Command, args []string) error {
+			if account == "" {
+				account = config.Config.DefaultAccount
+			}
+			if account == "" {
+				common.Must(cmd.Help())
+				log.Fatal("No account specified. Please specify with --account or set a default")
+			}
+
+			if len(args) == 0 {
+				return errors.New("please specify signald.group URL")
+			}
+			joinURL = args[0]
+
+			if !strings.HasPrefix(joinURL, "https://signal.group/#") {
+				return errors.New("invalid group link (must start with https://signal.group/#")
+			}
+
+			return nil
+		},
+		RunE: func(_ *cobra.Command, args []string) error {
+			go common.Signald.Listen(nil)
+			req := v1.GroupLinkInfoRequest{
+				Account: account,
+				Uri:     joinURL,
+			}
+
+			info, err := req.Submit(common.Signald)
+			if err != nil {
+				return err
+			}
+
+			switch common.OutputFormat {
+			case common.OutputFormatJSON, common.OutputFormatDefault:
+				return json.NewEncoder(os.Stdout).Encode(info)
+			}
+
+			return nil
+		},
+	}
+)

cmd/signaldctl/cmd/group/root.go

@@ -24,6 +24,7 @@ import (
 	"gitlab.com/signald/signald-go/cmd/signaldctl/cmd/group/join"
 	"gitlab.com/signald/signald-go/cmd/signaldctl/cmd/group/leave"
 	"gitlab.com/signald/signald-go/cmd/signaldctl/cmd/group/list"
+	"gitlab.com/signald/signald-go/cmd/signaldctl/cmd/group/preview"
 	"gitlab.com/signald/signald-go/cmd/signaldctl/cmd/group/removemember"
 	"gitlab.com/signald/signald-go/cmd/signaldctl/cmd/group/show"
 	"gitlab.com/signald/signald-go/cmd/signaldctl/cmd/group/update"
@@ -41,6 +42,7 @@ func init() {
 	GroupCmd.AddCommand(join.JoinGroupCmd)
 	GroupCmd.AddCommand(leave.LeaveGroupCmd)
 	GroupCmd.AddCommand(list.ListGroupCmd)
+	GroupCmd.AddCommand(preview.PreviewGroupCmd)
 	GroupCmd.AddCommand(removemember.RemoveMemberCmd)
 	GroupCmd.AddCommand(show.ShowGroupCmd)
 	GroupCmd.AddCommand(update.UpdateGroupCmd)