✨(dimail) synchronize mailboxes from dimail to our db

Synchronize mailboxes existing on dimail's api and not on our side,
on domains we are administrating.

src/backend/mailbox_manager/admin.py

@@ -1,9 +1,35 @@
 """Admin classes and registrations for People's mailbox manager app."""
 
-from django.contrib import admin
+from django.contrib import admin, messages
 from django.utils.translation import gettext_lazy as _
 
+from requests import exceptions
+
 from mailbox_manager import models
+from mailbox_manager.utils.dimail import DimailAPIClient
+
+
+@admin.action(description=_("Synchronise from dimail"))
+def sync_mailboxes_from_dimail(modeladmin, request, queryset):  # pylint: disable=unused-argument
+    """Admin action to synchronize existing mailboxes from dimail to our database."""
+    client = DimailAPIClient()
+
+    for domain in queryset:
+        try:
+            imported_mailboxes = client.synchronize_mailboxes_from_dimail(domain)
+        except exceptions.HTTPError as err:
+            messages.error(
+                request,
+                _(f"Synchronisation failed for {domain.name} with message: [{err}]"),
+            )
+        else:
+            messages.success(
+                request,
+                _(
+                    f"Synchronisation succeed for {domain.name}. "
+                    f"Imported mailboxes: {', '.join(imported_mailboxes)}"
+                ),
+            )
 
 
 class UserMailDomainAccessInline(admin.TabularInline):
@@ -28,6 +54,14 @@ class MailDomainAdmin(admin.ModelAdmin):
     search_fields = ("name",)
     readonly_fields = ["created_at", "slug"]
     inlines = (UserMailDomainAccessInline,)
+    actions = (sync_mailboxes_from_dimail,)
+
+
+@admin.register(models.Mailbox)
+class MailboxAdmin(admin.ModelAdmin):
+    """Admin for mailbox model."""
+
+    list_display = ("__str__", "first_name", "last_name")
 
 
 @admin.register(models.MailDomainAccess)
@@ -50,10 +84,3 @@ class MailDomainAccessInline(admin.TabularInline):
     autocomplete_fields = ["user", "domain"]
     model = models.MailDomainAccess
     readonly_fields = ("created_at", "updated_at")
-
-
-@admin.register(models.Mailbox)
-class MailboxAdmin(admin.ModelAdmin):
-    """Admin for mailbox model."""
-
-    list_display = ("__str__", "first_name", "last_name")