package main import ( "bytes" "context" "crypto/tls" "fmt" "html/template" "net/smtp" "strings" "time" jEmail "github.com/jordan-wright/email" "github.com/knz/strtime" "github.com/mailgun/mailgun-go/v4" ) // implements email sending, right now via smtp or mailgun. type emailClient interface { send(address, fromName, fromAddr string, email *Email) error } // Mailgun client implements emailClient. type Mailgun struct { client *mailgun.MailgunImpl } func (mg *Mailgun) send(address, fromName, fromAddr string, email *Email) error { message := mg.client.NewMessage( fmt.Sprintf("%s <%s>", fromName, fromAddr), email.subject, email.text, address, ) 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 } func (sm *SMTP) send(address, fromName, fromAddr string, email *Email) error { e := jEmail.NewEmail() e.Subject = email.subject e.From = fmt.Sprintf("%s <%s>", fromName, fromAddr) e.To = []string{address} e.Text = []byte(email.text) e.HTML = []byte(email.html) server := fmt.Sprintf("%s:%d", sm.server, sm.port) tlsConfig := &tls.Config{ InsecureSkipVerify: false, ServerName: sm.server, } var err error // err = e.Send(server, sm.auth) if sm.sslTLS { err = e.SendWithTLS(server, sm.auth, tlsConfig) } else { err = e.SendWithStartTLS(server, sm.auth, tlsConfig) } return err } // Emailer contains the email sender, email content, and methods to construct message content. type Emailer struct { fromAddr, fromName string lang emailLang sender emailClient } // Email stores content. type Email struct { subject string html, text string } func (emailer *Emailer) formatExpiry(expiry time.Time, tzaware bool, datePattern, timePattern string) (d, t, expiresIn string) { d, _ = strtime.Strftime(expiry, datePattern) t, _ = strtime.Strftime(expiry, timePattern) currentTime := time.Now() if tzaware { currentTime = currentTime.UTC() } _, _, days, hours, minutes, _ := timeDiff(expiry, currentTime) if days != 0 { expiresIn += fmt.Sprintf("%dd ", days) } if hours != 0 { expiresIn += fmt.Sprintf("%dh ", hours) } if minutes != 0 { expiresIn += fmt.Sprintf("%dm ", minutes) } 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 } 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) } else if method == "mailgun" { emailer.NewMailgun(app.config.Section("mailgun").Key("api_url").String(), app.config.Section("mailgun").Key("api_key").String()) } 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) { emailer.sender = &SMTP{ auth: smtp.PlainAuth("", username, password, server), server: server, port: port, sslTLS: sslTLS, } } func (emailer *Emailer) constructInvite(code string, invite Invite, app *appContext) (*Email, error) { email := &Email{ subject: app.config.Section("invite_emails").Key("subject").MustString(emailer.lang.InviteEmail.get("title")), } expiry := invite.ValidTill d, t, expiresIn := emailer.formatExpiry(expiry, false, app.datePattern, app.timePattern) message := app.config.Section("email").Key("message").String() inviteLink := app.config.Section("invite_emails").Key("url_base").String() inviteLink = fmt.Sprintf("%s/%s", inviteLink, code) for _, key := range []string{"html", "text"} { fpath := app.config.Section("invite_emails").Key("email_" + key).String() tpl, err := template.ParseFiles(fpath) if err != nil { return nil, err } var tplData bytes.Buffer err = tpl.Execute(&tplData, map[string]string{ "hello": emailer.lang.InviteEmail.get("hello"), "youHaveBeenInvited": emailer.lang.InviteEmail.get("youHaveBeenInvited"), "toJoin": emailer.lang.InviteEmail.get("toJoin"), "inviteExpiry": emailer.lang.InviteEmail.format("inviteExpiry", d, t, expiresIn), "linkButton": emailer.lang.InviteEmail.get("linkButton"), "invite_link": inviteLink, "message": message, }) if err != nil { return nil, err } if key == "html" { email.html = tplData.String() } else { email.text = tplData.String() } } return email, nil } func (emailer *Emailer) constructExpiry(code string, invite Invite, app *appContext) (*Email, error) { email := &Email{ subject: emailer.lang.InviteExpiry.get("title"), } expiry := app.formatDatetime(invite.ValidTill) for _, key := range []string{"html", "text"} { fpath := app.config.Section("notifications").Key("expiry_" + key).String() tpl, err := template.ParseFiles(fpath) if err != nil { return nil, err } var tplData bytes.Buffer err = tpl.Execute(&tplData, map[string]string{ "inviteExpired": emailer.lang.InviteExpiry.get("inviteExpired"), "expiredAt": emailer.lang.InviteExpiry.format("expiredAt", "\""+code+"\"", expiry), "notificationNotice": emailer.lang.InviteExpiry.get("notificationNotice"), }) if err != nil { return nil, err } if key == "html" { email.html = tplData.String() } else { email.text = tplData.String() } } return email, nil } func (emailer *Emailer) constructCreated(code, username, address string, invite Invite, app *appContext) (*Email, error) { email := &Email{ subject: emailer.lang.UserCreated.get("title"), } created := app.formatDatetime(invite.Created) var tplAddress string if app.config.Section("email").Key("no_username").MustBool(false) { tplAddress = "n/a" } else { tplAddress = address } for _, key := range []string{"html", "text"} { fpath := app.config.Section("notifications").Key("created_" + key).String() tpl, err := template.ParseFiles(fpath) if err != nil { return nil, err } var tplData bytes.Buffer err = tpl.Execute(&tplData, map[string]string{ "aUserWasCreated": emailer.lang.UserCreated.format("aUserWasCreated", "\""+code+"\""), "name": emailer.lang.UserCreated.get("name"), "address": emailer.lang.UserCreated.get("emailAddress"), "time": emailer.lang.UserCreated.get("time"), "nameVal": username, "addressVal": tplAddress, "timeVal": created, "notificationNotice": emailer.lang.UserCreated.get("notificationNotice"), }) if err != nil { return nil, err } if key == "html" { email.html = tplData.String() } else { email.text = tplData.String() } } return email, nil } func (emailer *Emailer) constructReset(pwr PasswordReset, app *appContext) (*Email, error) { email := &Email{ subject: app.config.Section("password_resets").Key("subject").MustString(emailer.lang.PasswordReset.get("title")), } d, t, expiresIn := emailer.formatExpiry(pwr.Expiry, true, app.datePattern, app.timePattern) message := app.config.Section("email").Key("message").String() for _, key := range []string{"html", "text"} { fpath := app.config.Section("password_resets").Key("email_" + key).String() tpl, err := template.ParseFiles(fpath) if err != nil { return nil, err } var tplData bytes.Buffer err = tpl.Execute(&tplData, map[string]string{ "helloUser": emailer.lang.PasswordReset.format("helloUser", pwr.Username), "someoneHasRequestedReset": emailer.lang.PasswordReset.get("someoneHasRequestedReset"), "ifItWasYou": emailer.lang.PasswordReset.get("ifItWasYou"), "codeExpiry": emailer.lang.PasswordReset.format("codeExpiry", d, t, expiresIn), "ifItWasNotYou": emailer.lang.PasswordReset.get("ifItWasNotYou"), "pin": emailer.lang.PasswordReset.get("pin"), "pinVal": pwr.Pin, "message": message, }) if err != nil { return nil, err } if key == "html" { email.html = tplData.String() } else { email.text = tplData.String() } } return email, nil } func (emailer *Emailer) constructDeleted(reason string, app *appContext) (*Email, error) { email := &Email{ subject: app.config.Section("deletion").Key("subject").MustString(emailer.lang.UserDeleted.get("title")), } for _, key := range []string{"html", "text"} { fpath := app.config.Section("deletion").Key("email_" + key).String() tpl, err := template.ParseFiles(fpath) if err != nil { return nil, err } var tplData bytes.Buffer err = tpl.Execute(&tplData, map[string]string{ "yourAccountWasDeleted": emailer.lang.UserDeleted.get("yourAccountWasDeleted"), "reason": emailer.lang.UserDeleted.get("reason"), "reasonVal": reason, }) if err != nil { return nil, err } if key == "html" { email.html = tplData.String() } else { email.text = tplData.String() } } return email, nil } func (emailer *Emailer) constructWelcome(username string, app *appContext) (*Email, error) { email := &Email{ subject: app.config.Section("welcome_email").Key("subject").MustString(emailer.lang.WelcomeEmail.get("title")), } for _, key := range []string{"html", "text"} { fpath := app.config.Section("welcome_email").Key("email_" + key).String() tpl, err := template.ParseFiles(fpath) if err != nil { return nil, err } var tplData bytes.Buffer err = tpl.Execute(&tplData, map[string]string{ "welcome": emailer.lang.WelcomeEmail.get("welcome"), "youCanLoginWith": emailer.lang.WelcomeEmail.get("youCanLoginWith"), "jellyfinURL": emailer.lang.WelcomeEmail.get("jellyfinURL"), "jellyfinURLVal": app.config.Section("jellyfin").Key("public_server").String(), "username": emailer.lang.WelcomeEmail.get("username"), "usernameVal": username, "message": app.config.Section("email").Key("message").String(), }) if err != nil { return nil, err } if key == "html" { email.html = tplData.String() } else { email.text = tplData.String() } } return email, nil } // calls the send method in the underlying emailClient. func (emailer *Emailer) send(address string, email *Email) error { return emailer.sender.send(address, emailer.fromName, emailer.fromAddr, email) }