[MM-32543] - Add ability to send email to admin that users are trying to invite others (#16882)

* [MM-32543] - Add ability to send email to admin that users are trying to join

* Update email template

* Feedback impl-1

* Fix test

* Feedback impl-2

* Fix error

* Feedback impl

* Use 413 status code

* make i18n-extract

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

api4/cloud.go

@@ -35,6 +35,7 @@ func (api *API) InitCloud() {
 	api.BaseRoutes.Cloud.Handle("/subscription", api.ApiSessionRequired(getSubscription)).Methods("GET")
 	api.BaseRoutes.Cloud.Handle("/subscription/invoices", api.ApiSessionRequired(getInvoicesForSubscription)).Methods("GET")
 	api.BaseRoutes.Cloud.Handle("/subscription/invoices/{invoice_id:in_[A-Za-z0-9]+}/pdf", api.ApiSessionRequired(getSubscriptionInvoicePDF)).Methods("GET")
+	api.BaseRoutes.Cloud.Handle("/subscription/limitreached/invite", api.ApiSessionRequired(sendAdminUpgradeRequestEmail)).Methods("POST")
 	api.BaseRoutes.Cloud.Handle("/subscription/stats", api.ApiHandler(getSubscriptionStats)).Methods("GET")
 
 	// POST /api/v4/cloud/webhook
@@ -389,3 +390,29 @@ func handleCWSWebhook(c *Context, w http.ResponseWriter, r *http.Request) {
 
 	ReturnStatusOK(w)
 }
+
+func sendAdminUpgradeRequestEmail(c *Context, w http.ResponseWriter, r *http.Request) {
+	if c.App.Srv().License() == nil || !*c.App.Srv().License().Features.Cloud {
+		c.Err = model.NewAppError("Api4.sendAdminUpgradeRequestEmail", "api.cloud.license_error", nil, "", http.StatusNotImplemented)
+		return
+	}
+
+	user, err := c.App.GetUser(c.App.Session().UserId)
+	if err != nil {
+		c.Err = model.NewAppError("Api4.sendAdminUpgradeRequestEmail", err.Id, nil, err.Error(), err.StatusCode)
+		return
+	}
+
+	sub, err := c.App.Cloud().GetSubscription()
+	if err != nil {
+		c.Err = model.NewAppError("Api4.sendAdminUpgradeRequestEmail", "api.cloud.request_error", nil, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	if err = c.App.SendAdminUpgradeRequestEmail(user.Username, sub); err != nil {
+		c.Err = model.NewAppError("Api4.sendAdminUpgradeRequestEmail", err.Id, nil, err.Error(), err.StatusCode)
+		return
+	}
+
+	ReturnStatusOK(w)
+}