package main import ( "bytes" "context" "crypto/tls" "crypto/x509" "errors" "fmt" "html/template" "io" "io/fs" "net/smtp" "os" "strconv" "strings" "sync" textTemplate "text/template" "time" "github.com/gomarkdown/markdown" "github.com/gomarkdown/markdown/html" "github.com/itchyny/timefmt-go" jEmail "github.com/jordan-wright/email" "github.com/mailgun/mailgun-go/v4" ) // implements email sending, right now via smtp or mailgun. type EmailClient interface { Send(fromName, fromAddr string, message *Message, address ...string) error } type DummyClient struct{} func (dc *DummyClient) Send(fromName, fromAddr string, email *Message, address ...string) error { fmt.Printf("FROM: %s <%s>\nTO: %s\nTEXT: %s\n", fromName, fromAddr, strings.Join(address, ", "), email.Text) return nil } // Mailgun client implements emailClient. type Mailgun struct { client *mailgun.MailgunImpl } func (mg *Mailgun) Send(fromName, fromAddr string, email *Message, address ...string) error { message := mg.client.NewMessage( fmt.Sprintf("%s <%s>", fromName, fromAddr), email.Subject, email.Text, ) for _, a := range address { // Adding variable tells mailgun to do a batch send, so users don't see other recipients. message.AddRecipientAndVariables(a, map[string]interface{}{"unique_id": a}) } message.SetHtml(email.HTML) ctx, cancel := context.WithTimeout(context.Background(), time.Second*10) defer cancel() _, _, err := mg.client.Send(ctx, message) return err } // SMTP supports SSL/TLS and STARTTLS; implements emailClient. type SMTP struct { sslTLS bool server string port int auth smtp.Auth tlsConfig *tls.Config } func (sm *SMTP) Send(fromName, fromAddr string, email *Message, address ...string) error { server := fmt.Sprintf("%s:%d", sm.server, sm.port) from := fmt.Sprintf("%s <%s>", fromName, fromAddr) var wg sync.WaitGroup var err error for _, addr := range address { wg.Add(1) go func(addr string) { defer wg.Done() e := jEmail.NewEmail() e.Subject = email.Subject e.From = from e.Text = []byte(email.Text) e.HTML = []byte(email.HTML) e.To = []string{addr} if sm.sslTLS { err = e.SendWithTLS(server, sm.auth, sm.tlsConfig) } else { err = e.SendWithStartTLS(server, sm.auth, sm.tlsConfig) } }(addr) } wg.Wait() return err } // Emailer contains the email sender, translations, and methods to construct messages. type Emailer struct { fromAddr, fromName string lang emailLang sender EmailClient } // Message stores content. type Message struct { Subject string `json:"subject"` HTML string `json:"html"` Text string `json:"text"` Markdown string `json:"markdown"` } func (emailer *Emailer) formatExpiry(expiry time.Time, tzaware bool, datePattern, timePattern string) (d, t, expiresIn string) { d = timefmt.Format(expiry, datePattern) t = timefmt.Format(expiry, timePattern) currentTime := time.Now() if tzaware { currentTime = currentTime.UTC() } _, _, days, hours, minutes, _ := timeDiff(expiry, currentTime) if days != 0 { expiresIn += strconv.Itoa(days) + "d " } if hours != 0 { expiresIn += strconv.Itoa(hours) + "h " } if minutes != 0 { expiresIn += strconv.Itoa(minutes) + "m " } expiresIn = strings.TrimSuffix(expiresIn, " ") return } // NewEmailer configures and returns a new emailer. func NewEmailer(app *appContext) *Emailer { emailer := &Emailer{ fromAddr: app.config.Section("email").Key("address").String(), fromName: app.config.Section("email").Key("from").String(), lang: app.storage.lang.Email[app.storage.lang.chosenEmailLang], } method := app.config.Section("email").Key("method").String() if method == "smtp" { sslTls := false if app.config.Section("smtp").Key("encryption").String() == "ssl_tls" { sslTls = true } username := "" if u := app.config.Section("smtp").Key("username").MustString(""); u != "" { username = u } else { username = emailer.fromAddr } err := emailer.NewSMTP(app.config.Section("smtp").Key("server").String(), app.config.Section("smtp").Key("port").MustInt(465), username, app.config.Section("smtp").Key("password").String(), sslTls, app.config.Section("smtp").Key("ssl_cert").MustString("")) if err != nil { app.err.Printf("Error while initiating SMTP mailer: %v", err) } } else if method == "mailgun" { emailer.NewMailgun(app.config.Section("mailgun").Key("api_url").String(), app.config.Section("mailgun").Key("api_key").String()) } else if method == "dummy" { emailer.sender = &DummyClient{} } return emailer } // NewMailgun returns a Mailgun emailClient. func (emailer *Emailer) NewMailgun(url, key string) { sender := &Mailgun{ client: mailgun.NewMailgun(strings.Split(emailer.fromAddr, "@")[1], key), } // Mailgun client takes the base url, so we need to trim off the end (e.g 'v3/messages') if strings.Contains(url, "messages") { url = url[0:strings.LastIndex(url, "/")] url = url[0:strings.LastIndex(url, "/")] } sender.client.SetAPIBase(url) emailer.sender = sender } // NewSMTP returns an SMTP emailClient. func (emailer *Emailer) NewSMTP(server string, port int, username, password string, sslTLS bool, certPath string) (err error) { rootCAs, err := x509.SystemCertPool() if rootCAs == nil || err != nil { rootCAs = x509.NewCertPool() } if certPath != "" { var cert []byte cert, err = os.ReadFile(certPath) if rootCAs.AppendCertsFromPEM(cert) == false { err = errors.New("Failed to append cert to pool") } } emailer.sender = &SMTP{ auth: smtp.PlainAuth("", username, password, server), server: server, port: port, sslTLS: sslTLS, tlsConfig: &tls.Config{ InsecureSkipVerify: false, ServerName: server, RootCAs: rootCAs, }, } return } type templ interface { Execute(wr io.Writer, data interface{}) error } func (emailer *Emailer) construct(app *appContext, section, keyFragment string, data map[string]interface{}) (html, text, markdown string, err error) { var tpl templ if substituteStrings == "" { data["jellyfin"] = "Jellyfin" } else { data["jellyfin"] = substituteStrings } var keys []string plaintext := app.config.Section("email").Key("plaintext").MustBool(false) if plaintext { if telegramEnabled { keys = []string{"text"} text, markdown = "", "" } else { keys = []string{"text"} text = "" } } else { if telegramEnabled { keys = []string{"html", "text", "markdown"} } else { keys = []string{"html", "text"} } } for _, key := range keys { var filesystem fs.FS var fpath string if key == "markdown" { filesystem, fpath = app.GetPath(section, keyFragment+"text") } else { filesystem, fpath = app.GetPath(section, keyFragment+key) } if key == "html" { tpl, err = template.ParseFS(filesystem, fpath) } else { tpl, err = textTemplate.ParseFS(filesystem, fpath) } if err != nil { return } // For constructTemplate, if "md" is found in data it's used in stead of "text". foundMarkdown := false if key == "markdown" { _, foundMarkdown = data["md"] if foundMarkdown { data["plaintext"], data["md"] = data["md"], data["plaintext"] } } var tplData bytes.Buffer err = tpl.Execute(&tplData, data) if err != nil { return } if foundMarkdown { data["plaintext"], data["md"] = data["md"], data["plaintext"] } if key == "html" { html = tplData.String() } else if key == "text" { text = tplData.String() } else { markdown = tplData.String() } } return } func (emailer *Emailer) confirmationValues(code, username, key string, app *appContext, noSub bool) map[string]interface{} { template := map[string]interface{}{ "clickBelow": emailer.lang.EmailConfirmation.get("clickBelow"), "ifItWasNotYou": emailer.lang.Strings.get("ifItWasNotYou"), "confirmEmail": emailer.lang.EmailConfirmation.get("confirmEmail"), "message": "", "username": username, } if noSub { template["helloUser"] = emailer.lang.Strings.get("helloUser") empty := []string{"confirmationURL"} for _, v := range empty { template[v] = "{" + v + "}" } } else { message := app.config.Section("messages").Key("message").String() inviteLink := app.config.Section("invite_emails").Key("url_base").String() inviteLink = fmt.Sprintf("%s/%s?key=%s", inviteLink, code, key) template["helloUser"] = emailer.lang.Strings.template("helloUser", tmpl{"username": username}) template["confirmationURL"] = inviteLink template["message"] = message } return template } func (emailer *Emailer) constructConfirmation(code, username, key string, app *appContext, noSub bool) (*Message, error) { email := &Message{ Subject: app.config.Section("email_confirmation").Key("subject").MustString(emailer.lang.EmailConfirmation.get("title")), } var err error template := emailer.confirmationValues(code, username, key, app, noSub) if app.storage.customEmails.EmailConfirmation.Enabled { content := templateEmail( app.storage.customEmails.EmailConfirmation.Content, app.storage.customEmails.EmailConfirmation.Variables, nil, template, ) email, err = emailer.constructTemplate(email.Subject, content, app) } else { email.HTML, email.Text, email.Markdown, err = emailer.construct(app, "email_confirmation", "email_", template) } if err != nil { return nil, err } return email, nil } func (emailer *Emailer) constructTemplate(subject, md string, app *appContext) (*Message, error) { email := &Message{Subject: subject} renderer := html.NewRenderer(html.RendererOptions{Flags: html.Smartypants}) html := markdown.ToHTML([]byte(md), nil, renderer) text := stripMarkdown(md) message := app.config.Section("messages").Key("message").String() var err error email.HTML, email.Text, email.Markdown, err = emailer.construct(app, "template_email", "email_", map[string]interface{}{ "text": template.HTML(html), "plaintext": text, "message": message, "md": md, }) if err != nil { return nil, err } return email, nil } func (emailer *Emailer) inviteValues(code string, invite Invite, app *appContext, noSub bool) map[string]interface{} { expiry := invite.ValidTill d, t, expiresIn := emailer.formatExpiry(expiry, false, app.datePattern, app.timePattern) message := app.config.Section("messages").Key("message").String() inviteLink := app.config.Section("invite_emails").Key("url_base").String() inviteLink = fmt.Sprintf("%s/%s", inviteLink, code) template := map[string]interface{}{ "hello": emailer.lang.InviteEmail.get("hello"), "youHaveBeenInvited": emailer.lang.InviteEmail.get("youHaveBeenInvited"), "toJoin": emailer.lang.InviteEmail.get("toJoin"), "linkButton": emailer.lang.InviteEmail.get("linkButton"), "message": "", "date": d, "time": t, "expiresInMinutes": expiresIn, } if noSub { template["inviteExpiry"] = emailer.lang.InviteEmail.get("inviteExpiry") empty := []string{"inviteURL"} for _, v := range empty { template[v] = "{" + v + "}" } } else { template["inviteExpiry"] = emailer.lang.InviteEmail.template("inviteExpiry", tmpl{"date": d, "time": t, "expiresInMinutes": expiresIn}) template["inviteURL"] = inviteLink template["message"] = message } return template } func (emailer *Emailer) constructInvite(code string, invite Invite, app *appContext, noSub bool) (*Message, error) { email := &Message{ Subject: app.config.Section("invite_emails").Key("subject").MustString(emailer.lang.InviteEmail.get("title")), } template := emailer.inviteValues(code, invite, app, noSub) var err error if app.storage.customEmails.InviteEmail.Enabled { content := templateEmail( app.storage.customEmails.InviteEmail.Content, app.storage.customEmails.InviteEmail.Variables, nil, template, ) email, err = emailer.constructTemplate(email.Subject, content, app) } else { email.HTML, email.Text, email.Markdown, err = emailer.construct(app, "invite_emails", "email_", template) } if err != nil { return nil, err } return email, nil } func (emailer *Emailer) expiryValues(code string, invite Invite, app *appContext, noSub bool) map[string]interface{} { expiry := app.formatDatetime(invite.ValidTill) template := map[string]interface{}{ "inviteExpired": emailer.lang.InviteExpiry.get("inviteExpired"), "notificationNotice": emailer.lang.InviteExpiry.get("notificationNotice"), "code": "\"" + code + "\"", "time": expiry, } if noSub { template["expiredAt"] = emailer.lang.InviteExpiry.get("expiredAt") } else { template["expiredAt"] = emailer.lang.InviteExpiry.template("expiredAt", tmpl{"code": template["code"].(string), "time": template["time"].(string)}) } return template } func (emailer *Emailer) constructExpiry(code string, invite Invite, app *appContext, noSub bool) (*Message, error) { email := &Message{ Subject: emailer.lang.InviteExpiry.get("title"), } var err error template := emailer.expiryValues(code, invite, app, noSub) if app.storage.customEmails.InviteExpiry.Enabled { content := templateEmail( app.storage.customEmails.InviteExpiry.Content, app.storage.customEmails.InviteExpiry.Variables, nil, template, ) email, err = emailer.constructTemplate(email.Subject, content, app) } else { email.HTML, email.Text, email.Markdown, err = emailer.construct(app, "notifications", "expiry_", template) } if err != nil { return nil, err } return email, nil } func (emailer *Emailer) createdValues(code, username, address string, invite Invite, app *appContext, noSub bool) map[string]interface{} { template := map[string]interface{}{ "nameString": emailer.lang.Strings.get("name"), "addressString": emailer.lang.Strings.get("emailAddress"), "timeString": emailer.lang.UserCreated.get("time"), "notificationNotice": "", "code": "\"" + code + "\"", } if noSub { template["aUserWasCreated"] = emailer.lang.UserCreated.get("aUserWasCreated") empty := []string{"name", "address", "time"} for _, v := range empty { template[v] = "{" + v + "}" } } else { created := app.formatDatetime(invite.Created) var tplAddress string if app.config.Section("email").Key("no_username").MustBool(false) { tplAddress = "n/a" } else { tplAddress = address } template["aUserWasCreated"] = emailer.lang.UserCreated.template("aUserWasCreated", tmpl{"code": template["code"].(string)}) template["name"] = username template["address"] = tplAddress template["time"] = created template["notificationNotice"] = emailer.lang.UserCreated.get("notificationNotice") } return template } func (emailer *Emailer) constructCreated(code, username, address string, invite Invite, app *appContext, noSub bool) (*Message, error) { email := &Message{ Subject: emailer.lang.UserCreated.get("title"), } template := emailer.createdValues(code, username, address, invite, app, noSub) var err error if app.storage.customEmails.UserCreated.Enabled { content := templateEmail( app.storage.customEmails.UserCreated.Content, app.storage.customEmails.UserCreated.Variables, nil, template, ) email, err = emailer.constructTemplate(email.Subject, content, app) } else { email.HTML, email.Text, email.Markdown, err = emailer.construct(app, "notifications", "created_", template) } if err != nil { return nil, err } return email, nil } func (emailer *Emailer) resetValues(pwr PasswordReset, app *appContext, noSub bool) map[string]interface{} { d, t, expiresIn := emailer.formatExpiry(pwr.Expiry, true, app.datePattern, app.timePattern) message := app.config.Section("messages").Key("message").String() template := map[string]interface{}{ "someoneHasRequestedReset": emailer.lang.PasswordReset.get("someoneHasRequestedReset"), "ifItWasNotYou": emailer.lang.Strings.get("ifItWasNotYou"), "pinString": emailer.lang.PasswordReset.get("pin"), "link_reset": false, "message": "", "username": pwr.Username, "date": d, "time": t, "expiresInMinutes": expiresIn, } linkResetEnabled := app.config.Section("password_resets").Key("link_reset").MustBool(false) if linkResetEnabled { template["ifItWasYou"] = emailer.lang.PasswordReset.get("ifItWasYouLink") } else { template["ifItWasYou"] = emailer.lang.PasswordReset.get("ifItWasYou") } if noSub { template["helloUser"] = emailer.lang.Strings.get("helloUser") template["codeExpiry"] = emailer.lang.PasswordReset.get("codeExpiry") empty := []string{"pin"} for _, v := range empty { template[v] = "{" + v + "}" } } else { template["helloUser"] = emailer.lang.Strings.template("helloUser", tmpl{"username": pwr.Username}) template["codeExpiry"] = emailer.lang.PasswordReset.template("codeExpiry", tmpl{"date": d, "time": t, "expiresInMinutes": expiresIn}) inviteLink := app.config.Section("invite_emails").Key("url_base").String() if linkResetEnabled { if inviteLink != "" { // Strip /invite form end of this URL, ik its ugly. template["link_reset"] = true pinLink := fmt.Sprintf("%s/reset?pin=%s", strings.Replace(inviteLink, "/invite", "", 1), pwr.Pin) template["pin"] = pinLink // Only used in html email. template["pin_code"] = pwr.Pin } else { app.info.Println("Password Reset link disabled as no URL Base provided. Set in Settings > Invite Emails.") template["pin"] = pwr.Pin } } else { template["pin"] = pwr.Pin } template["message"] = message } return template } func (emailer *Emailer) constructReset(pwr PasswordReset, app *appContext, noSub bool) (*Message, error) { email := &Message{ Subject: app.config.Section("password_resets").Key("subject").MustString(emailer.lang.PasswordReset.get("title")), } template := emailer.resetValues(pwr, app, noSub) var err error if app.storage.customEmails.PasswordReset.Enabled { content := templateEmail( app.storage.customEmails.PasswordReset.Content, app.storage.customEmails.PasswordReset.Variables, nil, template, ) email, err = emailer.constructTemplate(email.Subject, content, app) } else { email.HTML, email.Text, email.Markdown, err = emailer.construct(app, "password_resets", "email_", template) } if err != nil { return nil, err } return email, nil } func (emailer *Emailer) deletedValues(reason string, app *appContext, noSub bool) map[string]interface{} { template := map[string]interface{}{ "yourAccountWas": emailer.lang.UserDeleted.get("yourAccountWasDeleted"), "reasonString": emailer.lang.Strings.get("reason"), "message": "", } if noSub { empty := []string{"reason"} for _, v := range empty { template[v] = "{" + v + "}" } } else { template["reason"] = reason template["message"] = app.config.Section("messages").Key("message").String() } return template } func (emailer *Emailer) constructDeleted(reason string, app *appContext, noSub bool) (*Message, error) { email := &Message{ Subject: app.config.Section("deletion").Key("subject").MustString(emailer.lang.UserDeleted.get("title")), } var err error template := emailer.deletedValues(reason, app, noSub) if app.storage.customEmails.UserDeleted.Enabled { content := templateEmail( app.storage.customEmails.UserDeleted.Content, app.storage.customEmails.UserDeleted.Variables, nil, template, ) email, err = emailer.constructTemplate(email.Subject, content, app) } else { email.HTML, email.Text, email.Markdown, err = emailer.construct(app, "deletion", "email_", template) } if err != nil { return nil, err } return email, nil } func (emailer *Emailer) disabledValues(reason string, app *appContext, noSub bool) map[string]interface{} { template := map[string]interface{}{ "yourAccountWas": emailer.lang.UserDisabled.get("yourAccountWasDisabled"), "reasonString": emailer.lang.Strings.get("reason"), "message": "", } if noSub { empty := []string{"reason"} for _, v := range empty { template[v] = "{" + v + "}" } } else { template["reason"] = reason template["message"] = app.config.Section("messages").Key("message").String() } return template } func (emailer *Emailer) constructDisabled(reason string, app *appContext, noSub bool) (*Message, error) { email := &Message{ Subject: app.config.Section("disable_enable").Key("subject_disabled").MustString(emailer.lang.UserDisabled.get("title")), } var err error template := emailer.disabledValues(reason, app, noSub) if app.storage.customEmails.UserDisabled.Enabled { content := templateEmail( app.storage.customEmails.UserDisabled.Content, app.storage.customEmails.UserDisabled.Variables, nil, template, ) email, err = emailer.constructTemplate(email.Subject, content, app) } else { email.HTML, email.Text, email.Markdown, err = emailer.construct(app, "disable_enable", "disabled_", template) } if err != nil { return nil, err } return email, nil } func (emailer *Emailer) enabledValues(reason string, app *appContext, noSub bool) map[string]interface{} { template := map[string]interface{}{ "yourAccountWas": emailer.lang.UserEnabled.get("yourAccountWasEnabled"), "reasonString": emailer.lang.Strings.get("reason"), "message": "", } if noSub { empty := []string{"reason"} for _, v := range empty { template[v] = "{" + v + "}" } } else { template["reason"] = reason template["message"] = app.config.Section("messages").Key("message").String() } return template } func (emailer *Emailer) constructEnabled(reason string, app *appContext, noSub bool) (*Message, error) { email := &Message{ Subject: app.config.Section("disable_enable").Key("subject_enabled").MustString(emailer.lang.UserEnabled.get("title")), } var err error template := emailer.enabledValues(reason, app, noSub) if app.storage.customEmails.UserEnabled.Enabled { content := templateEmail( app.storage.customEmails.UserEnabled.Content, app.storage.customEmails.UserEnabled.Variables, nil, template, ) email, err = emailer.constructTemplate(email.Subject, content, app) } else { email.HTML, email.Text, email.Markdown, err = emailer.construct(app, "disable_enable", "enabled_", template) } if err != nil { return nil, err } return email, nil } func (emailer *Emailer) welcomeValues(username string, expiry time.Time, app *appContext, noSub bool, custom bool) map[string]interface{} { template := map[string]interface{}{ "welcome": emailer.lang.WelcomeEmail.get("welcome"), "youCanLoginWith": emailer.lang.WelcomeEmail.get("youCanLoginWith"), "jellyfinURLString": emailer.lang.WelcomeEmail.get("jellyfinURL"), "usernameString": emailer.lang.Strings.get("username"), "message": "", "yourAccountWillExpire": "", } if noSub { empty := []string{"jellyfinURL", "username", "yourAccountWillExpire"} for _, v := range empty { template[v] = "{" + v + "}" } } else { template["jellyfinURL"] = app.config.Section("jellyfin").Key("public_server").String() template["username"] = username template["message"] = app.config.Section("messages").Key("message").String() exp := app.formatDatetime(expiry) if !expiry.IsZero() { if custom { template["yourAccountWillExpire"] = exp } else if !expiry.IsZero() { template["yourAccountWillExpire"] = emailer.lang.WelcomeEmail.template("yourAccountWillExpire", tmpl{ "date": exp, }) } } } return template } func (emailer *Emailer) constructWelcome(username string, expiry time.Time, app *appContext, noSub bool) (*Message, error) { email := &Message{ Subject: app.config.Section("welcome_email").Key("subject").MustString(emailer.lang.WelcomeEmail.get("title")), } var err error var template map[string]interface{} if app.storage.customEmails.WelcomeEmail.Enabled { template = emailer.welcomeValues(username, expiry, app, noSub, true) } else { template = emailer.welcomeValues(username, expiry, app, noSub, false) } if noSub { template["yourAccountWillExpire"] = emailer.lang.WelcomeEmail.template("yourAccountWillExpire", tmpl{ "date": "{yourAccountWillExpire}", }) } if app.storage.customEmails.WelcomeEmail.Enabled { content := templateEmail( app.storage.customEmails.WelcomeEmail.Content, app.storage.customEmails.WelcomeEmail.Variables, app.storage.customEmails.WelcomeEmail.Conditionals, template, ) email, err = emailer.constructTemplate(email.Subject, content, app) } else { email.HTML, email.Text, email.Markdown, err = emailer.construct(app, "welcome_email", "email_", template) } if err != nil { return nil, err } return email, nil } func (emailer *Emailer) userExpiredValues(app *appContext, noSub bool) map[string]interface{} { template := map[string]interface{}{ "yourAccountHasExpired": emailer.lang.UserExpired.get("yourAccountHasExpired"), "contactTheAdmin": emailer.lang.UserExpired.get("contactTheAdmin"), "message": "", } if !noSub { template["message"] = app.config.Section("messages").Key("message").String() } return template } func (emailer *Emailer) constructUserExpired(app *appContext, noSub bool) (*Message, error) { email := &Message{ Subject: app.config.Section("user_expiry").Key("subject").MustString(emailer.lang.UserExpired.get("title")), } var err error template := emailer.userExpiredValues(app, noSub) if app.storage.customEmails.UserExpired.Enabled { content := templateEmail( app.storage.customEmails.UserExpired.Content, app.storage.customEmails.UserExpired.Variables, nil, template, ) email, err = emailer.constructTemplate(email.Subject, content, app) } else { email.HTML, email.Text, email.Markdown, err = emailer.construct(app, "user_expiry", "email_", template) } if err != nil { return nil, err } return email, nil } // calls the send method in the underlying emailClient. func (emailer *Emailer) send(email *Message, address ...string) error { return emailer.sender.Send(emailer.fromName, emailer.fromAddr, email, address...) } func (app *appContext) sendByID(email *Message, ID ...string) error { for _, id := range ID { var err error if tgChat, ok := app.storage.telegram[id]; ok && tgChat.Contact && telegramEnabled { err = app.telegram.Send(email, tgChat.ChatID) } else if address, ok := app.storage.emails[id]; ok { err = app.email.send(email, address.(string)) } if err != nil { return err } } return nil } func (app *appContext) getAddressOrName(jfID string) string { if tgChat, ok := app.storage.telegram[jfID]; ok && tgChat.Contact && telegramEnabled { return "@" + tgChat.Username } if addr, ok := app.storage.emails[jfID]; ok { return addr.(string) } return "" }