GODT-1901: Allow to set IMAP SSL from UI

internal/frontend/bridge-gui/bridge-gui/qml/AccountView.qml

@@ -231,7 +231,7 @@ Item {
                             port:       Backend.portIMAP.toString()
                             username:   configuration.currentAddress
                             password:   root.user ? root.user.password : ""
-                            security:   "STARTTLS"
+                            security : Backend.useSSLforIMAP ? "SSL" : "STARTTLS"
                         }
 
                         Configuration {

internal/frontend/bridge-gui/bridge-gui/qml/ContentWrapper.qml

@@ -365,6 +365,14 @@ Item {
                     }
                 }
 
+                IMAPSettings { // 9
+                    colorScheme: root.colorScheme
+
+                    onBack: {
+                        rightContent.showGeneralSettings()
+                    }
+                }
+
                 function showAccount(index) {
                     if (index !== undefined && index >= 0){
                         accounts.currentIndex = index
@@ -380,6 +388,7 @@ Item {
                 function showLocalCacheSettings () { rightContent.currentIndex = 6 }
                 function showHelpView           () { rightContent.currentIndex = 7 }
                 function showBugReport          () { rightContent.currentIndex = 8 }
+                function showIMAPSettings       () { rightContent.currentIndex = 9 }
 
                 Connections {
                     target: Backend

internal/frontend/bridge-gui/bridge-gui/qml/GeneralSettings.qml

@@ -182,6 +182,19 @@ SettingsView {
         Layout.fillWidth: true
     }
 
+    SettingsItem {
+        id: imap
+        visible: root._isAdvancedShown
+        colorScheme: root.colorScheme
+        text: qsTr("IMAP connection mode")
+        actionText: qsTr("Change")
+        description: qsTr("Change the protocol Bridge and your client use to connect.")
+        type: SettingsItem.Button
+        onClicked: root.parent.showIMAPSettings()
+
+        Layout.fillWidth: true
+    }
+
     SettingsItem {
         id: smtp
         visible: root._isAdvancedShown

internal/frontend/bridge-gui/bridge-gui/qml/IMAPSettings.qml

@@ -0,0 +1,121 @@
+// Copyright (c) 2022 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/>.
+
+import QtQuick
+import QtQuick.Layouts
+import QtQuick.Controls
+import QtQuick.Controls.impl
+
+import Proton
+
+SettingsView {
+    id: root
+
+    fillHeight: false
+
+    Label {
+        colorScheme: root.colorScheme
+        text: qsTr("IMAP connection mode")
+        type: Label.Heading
+        Layout.fillWidth: true
+    }
+
+    Label {
+        colorScheme: root.colorScheme
+        text: qsTr("Changes require reconfiguration of email client. Bridge will automatically restart.")
+        type: Label.Body
+        color: root.colorScheme.text_weak
+        Layout.fillWidth: true
+        wrapMode: Text.WordWrap
+    }
+
+    ColumnLayout {
+        spacing: 16
+
+        ButtonGroup{ id: protocolSelection }
+
+        Label {
+            colorScheme: root.colorScheme
+            text: qsTr("IMAP connection security")
+        }
+
+        RadioButton {
+            id: sslButton
+            colorScheme: root.colorScheme
+            ButtonGroup.group: protocolSelection
+            text: qsTr("SSL")
+        }
+
+        RadioButton {
+            id: starttlsButton
+            colorScheme: root.colorScheme
+            ButtonGroup.group: protocolSelection
+            text: qsTr("STARTTLS")
+        }
+    }
+
+    Rectangle {
+        Layout.fillWidth: true
+        height: 1
+        color: root.colorScheme.border_weak
+    }
+
+    RowLayout {
+        spacing: 12
+
+        Button {
+            id: submitButton
+            colorScheme: root.colorScheme
+            text: qsTr("Save and restart")
+            onClicked: {
+                submitButton.loading = true
+                root.submit()
+            }
+
+            enabled: sslButton.checked !== Backend.useSSLforIMAP
+        }
+
+        Button {
+            colorScheme: root.colorScheme
+            text: qsTr("Cancel")
+            onClicked: root.back()
+            secondary: true
+        }
+
+        Connections {
+            target: Backend
+
+            function onToggleUseSSLFinished() {
+                submitButton.loading = false
+            }
+        }
+    }
+
+    function submit(){
+        submitButton.loading = true
+        Backend.toggleUseSSLforIMAP(sslButton.checked)
+    }
+
+    function setDefaultValues(){
+        sslButton.checked = Backend.useSSLforIMAP
+        starttlsButton.checked = !Backend.useSSLforIMAP
+    }
+
+    onVisibleChanged: {
+        root.setDefaultValues()
+    }
+}