Guest accounts feature (#11428)

* MM-14139: Creating permissions for invite/promote/demote guests (#10778)

* MM-14139: Creating permissions for invite/promote/demote guests

* Fixing tests

* Adding invite guest api endpoint (#10792)

* Adding invite guest api endpoint

* Adding i18n

* Adding some tests

* WIP

* Migrating Token.Extra info to bigger size (2048)

* Fixing tests

* Adding client function for invite guests

* Adding send guests invites tests

* Renaming file from guest to guest_invite

* Adding Promote/Demote users from/to guest endpoints (#10791)

* Adding Promote/Demote users from/to guest endpoints

* Adding i18n translations

* Adding the client functions

* Using getQueryBuilder function

* Addressing PR review comments

* Adding default channels to users on promte from guest (#10851)

* Adding default channels to users on promte from guest

* Addressing PR review comments

* Fixing merge problems

* Sending websockets events on promote/demote (#11403)

* Sending websockets events on promote/demote

* Fixing merge problems

* Fixing govet shadowing problem

* Fixing feature branch tests

* Avoiding leaking users data through websockets for guest accounts (#11489)

* Avoiding leaking users data through websockets for guest accounts

* Adding tests and fixing code error

* Fixing i18n

* Allow to enable/disable guests and other extra config settings (#11481)

* Allow to enable/disable guests and other extra config settings

* Fixing tests and moving license and config validation to api level

* Update api4/role_test.go

Co-Authored-By: George Goldberg <george@gberg.me>

* Update api4/role_test.go

Co-Authored-By: George Goldberg <george@gberg.me>

* Fixing typo

* fixing tests

* Managing correctly the guest channel leave behavior (#11578)

* MM-15134: Removing guests from teams or system on leave channels if needed

* WIP

* No deactivating the guest user when leave the last team

* Adding a couple of tests

* Fixing shadow variables

* Fixing tests

* fixing tests

* fixing shadow variables

* Adding guest counts for channel stats (#11646)

* Adding guest counts for channel stats

* Adding tests

* Fixing tests

* Fixing guest domain restrictions (#11660)

* Adding needed migration for the database

* Fixing migration

app/email.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"net/url"
 	"path"
+	"strings"
 
 	"net/http"
 
@@ -357,6 +358,87 @@ func (a *App) SendInviteEmails(team *model.Team, senderName string, senderUserId
 	}
 }
 
+func (a *App) SendGuestInviteEmails(team *model.Team, channels []*model.Channel, senderName string, senderUserId string, invites []string, siteURL string, message string) {
+	if a.Srv.EmailRateLimiter == nil {
+		a.Log.Error("Email invite not sent, rate limiting could not be setup.", mlog.String("user_id", senderUserId), mlog.String("team_id", team.Id))
+		return
+	}
+	rateLimited, result, err := a.Srv.EmailRateLimiter.RateLimit(senderUserId, len(invites))
+	if err != nil {
+		a.Log.Error("Error rate limiting invite email.", mlog.String("user_id", senderUserId), mlog.String("team_id", team.Id), mlog.Err(err))
+		return
+	}
+
+	if rateLimited {
+		a.Log.Error("Invite emails rate limited.",
+			mlog.String("user_id", senderUserId),
+			mlog.String("team_id", team.Id),
+			mlog.String("retry_after", result.RetryAfter.String()),
+			mlog.Err(err))
+		return
+	}
+
+	for _, invite := range invites {
+		if len(invite) > 0 {
+			senderRole := utils.T("api.team.invite_members.member")
+
+			subject := utils.T("api.templates.invite_guest_subject",
+				map[string]interface{}{"SenderName": senderName,
+					"TeamDisplayName": team.DisplayName,
+					"SiteName":        a.ClientConfig()["SiteName"]})
+
+			bodyPage := a.NewEmailTemplate("invite_body", model.DEFAULT_LOCALE)
+			bodyPage.Props["SiteURL"] = siteURL
+			bodyPage.Props["Title"] = utils.T("api.templates.invite_body.title")
+			bodyPage.Html["Info"] = utils.TranslateAsHtml(utils.T, "api.templates.invite_body_guest.info",
+				map[string]interface{}{"SenderStatus": senderRole, "SenderName": senderName, "TeamDisplayName": team.DisplayName})
+			bodyPage.Props["Button"] = utils.T("api.templates.invite_body.button")
+			bodyPage.Props["Message"] = ""
+			if message != "" {
+				bodyPage.Props["Message"] = message
+			}
+			bodyPage.Html["ExtraInfo"] = utils.TranslateAsHtml(utils.T, "api.templates.invite_body.extra_info",
+				map[string]interface{}{"TeamDisplayName": team.DisplayName})
+			bodyPage.Props["TeamURL"] = siteURL + "/" + team.Name
+
+			channelIds := []string{}
+			for _, channel := range channels {
+				channelIds = append(channelIds, channel.Id)
+			}
+
+			token := model.NewToken(
+				TOKEN_TYPE_GUEST_INVITATION,
+				model.MapToJson(map[string]string{
+					"teamId":   team.Id,
+					"channels": strings.Join(channelIds, " "),
+					"email":    invite,
+					"guest":    "true",
+				}),
+			)
+
+			props := make(map[string]string)
+			props["email"] = invite
+			props["display_name"] = team.DisplayName
+			props["name"] = team.Name
+			data := model.MapToJson(props)
+
+			if err := a.Srv.Store.Token().Save(token); err != nil {
+				mlog.Error(fmt.Sprintf("Failed to send invite email successfully err=%v", err))
+				continue
+			}
+			bodyPage.Props["Link"] = fmt.Sprintf("%s/signup_user_complete/?d=%s&t=%s", siteURL, url.QueryEscape(data), url.QueryEscape(token.Token))
+
+			if !*a.Config().EmailSettings.SendEmailNotifications {
+				mlog.Info(fmt.Sprintf("sending invitation to %v %v", invite, bodyPage.Props["Link"]))
+			}
+
+			if err := a.SendMail(invite, subject, bodyPage.Render()); err != nil {
+				mlog.Error(fmt.Sprintf("Failed to send invite email successfully err=%v", err))
+			}
+		}
+	}
+}
+
 func (a *App) NewEmailTemplate(name, locale string) *utils.HTMLTemplate {
 	t := utils.NewHTMLTemplate(a.HTMLTemplates(), name)