feat(GODT-2759): CLI debug commands

Add debug commands to CLI to diagnose potential bride problems.
Currently we only have a command which validates whether the state of
all the mailboxes reported by IMAP matches what is currently available
on the proton servers.

internal/frontend/cli/debug.go

@@ -0,0 +1,42 @@
+// Copyright (c) 2023 Proton AG
+//
+// This file is part of Proton Mail Bridge.
+//
+// Proton Mail Bridge 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.
+//
+// Proton Mail Bridge 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 Proton Mail Bridge.  If not, see <https://www.gnu.org/licenses/>.
+
+package cli
+
+import (
+	"context"
+
+	"github.com/abiosoft/ishell"
+)
+
+func (f *frontendCLI) debugMailboxState(c *ishell.Context) {
+	f.ShowPrompt(false)
+	defer f.ShowPrompt(true)
+
+	checkFlags := f.yesNoQuestion("Also check message flags")
+
+	c.Println("Starting state check. Note that depending on your message count this may take a while.")
+
+	if err := f.bridge.CheckClientState(context.Background(), checkFlags, func(s string) {
+		c.Println(s)
+	}); err != nil {
+		c.Printf("State check failed : %v", err)
+		return
+	}
+
+	c.Println("State check finished, see log for more details.")
+}

internal/frontend/cli/frontend.go

@@ -312,6 +312,19 @@ func New(
 	})
 	fe.AddCmd(telemetryCmd)
 
+	dbgCmd := &ishell.Cmd{
+		Name: "debug",
+		Help: "Debug diagnostics ",
+	}
+
+	dbgCmd.AddCmd(&ishell.Cmd{
+		Name: "mailbox-state",
+		Help: "Verify local mailbox state against proton server state",
+		Func: fe.debugMailboxState,
+	})
+
+	fe.AddCmd(dbgCmd)
+
 	go fe.watchEvents(eventCh)
 
 	go func() {