Decouple emailservice from app package (#17827)

* decouple emailservice from app package

* fix some escaped errors

* move email package under app directory

* fix i18n

* reflect review comments

api4/team_local.go

@@ -4,11 +4,13 @@
 package api4
 
 import (
+	"fmt"
 	"net/http"
 	"strings"
 
 	"github.com/pkg/errors"
 
+	"github.com/mattermost/mattermost-server/v5/app/email"
 	"github.com/mattermost/mattermost-server/v5/audit"
 	"github.com/mattermost/mattermost-server/v5/model"
 	"github.com/mattermost/mattermost-server/v5/store"
@@ -126,7 +128,14 @@ func localInviteUsersToTeam(c *Context, w http.ResponseWriter, r *http.Request)
 		if len(goodEmails) > 0 {
 			err := c.App.Srv().EmailService.SendInviteEmails(team, "Administrator", "mmctl "+model.NewId(), goodEmails, *c.App.Config().ServiceSettings.SiteURL)
 			if err != nil {
-				c.Err = err
+				switch {
+				case errors.Is(err, email.NoRateLimiterError):
+					c.Err = model.NewAppError("SendInviteEmails", "app.email.no_rate_limiter.app_error", nil, fmt.Sprintf("team_id=%s", team.Id), http.StatusInternalServerError)
+				case errors.Is(err, email.SetupRateLimiterError):
+					c.Err = model.NewAppError("SendInviteEmails", "app.email.setup_rate_limiter.app_error", nil, fmt.Sprintf("team_id=%s, error=%v", team.Id, err), http.StatusInternalServerError)
+				default:
+					c.Err = model.NewAppError("SendInviteEmails", "app.email.rate_limit_exceeded.app_error", nil, fmt.Sprintf("team_id=%s, error=%v", team.Id, err), http.StatusRequestEntityTooLarge)
+				}
 				return
 			}
 		}
@@ -147,7 +156,14 @@ func localInviteUsersToTeam(c *Context, w http.ResponseWriter, r *http.Request)
 		}
 		err := c.App.Srv().EmailService.SendInviteEmails(team, "Administrator", "mmctl "+model.NewId(), emailList, *c.App.Config().ServiceSettings.SiteURL)
 		if err != nil {
-			c.Err = err
+			switch {
+			case errors.Is(err, email.NoRateLimiterError):
+				c.Err = model.NewAppError("SendInviteEmails", "app.email.no_rate_limiter.app_error", nil, fmt.Sprintf("team_id=%s", team.Id), http.StatusInternalServerError)
+			case errors.Is(err, email.SetupRateLimiterError):
+				c.Err = model.NewAppError("SendInviteEmails", "app.email.setup_rate_limiter.app_error", nil, fmt.Sprintf("team_id=%s, error=%v", team.Id, err), http.StatusInternalServerError)
+			default:
+				c.Err = model.NewAppError("SendInviteEmails", "app.email.rate_limit_exceeded.app_error", nil, fmt.Sprintf("team_id=%s, error=%v", team.Id, err), http.StatusRequestEntityTooLarge)
+			}
 			return
 		}
 		ReturnStatusOK(w)