feat: sync configurable OTP delivery providers

internal/mail/sender.go

@@ -1,154 +0,0 @@
-package mail
-
-import (
-	"bytes"
-	"context"
-	"crypto/tls"
-	"fmt"
-	"mime"
-	"net"
-	stdmail "net/mail"
-	"net/smtp"
-	"strings"
-	"time"
-)
-
-type Config struct {
-	Host     string
-	Port     int
-	Username string
-	Password string
-	From     string
-	FromName string
-	TLSMode  string
-	Timeout  time.Duration
-}
-
-type Sender interface {
-	SendLoginCode(ctx context.Context, to, code string, ttl time.Duration) error
-}
-
-type SMTP struct {
-	cfg Config
-}
-
-func NewSMTP(cfg Config) *SMTP {
-	if cfg.Timeout <= 0 {
-		cfg.Timeout = 10 * time.Second
-	}
-	cfg.TLSMode = strings.ToLower(strings.TrimSpace(cfg.TLSMode))
-	if cfg.TLSMode == "" {
-		cfg.TLSMode = "starttls"
-	}
-	if strings.TrimSpace(cfg.From) == "" {
-		cfg.From = cfg.Username
-	}
-	return &SMTP{cfg: cfg}
-}
-
-func (s *SMTP) SendLoginCode(ctx context.Context, to, code string, ttl time.Duration) error {
-	subject := "Your telesrv login code"
-	body := fmt.Sprintf("Your telesrv login code is %s.\n\nThis code expires in %s. If you did not request it, ignore this email.\n", code, humanTTL(ttl))
-	return s.send(ctx, to, subject, body)
-}
-
-func (s *SMTP) send(ctx context.Context, to, subject, body string) error {
-	if strings.TrimSpace(s.cfg.Host) == "" {
-		return fmt.Errorf("smtp host is empty")
-	}
-	from := strings.TrimSpace(s.cfg.From)
-	if from == "" {
-		return fmt.Errorf("smtp from is empty")
-	}
-	if _, err := stdmail.ParseAddress(to); err != nil {
-		return fmt.Errorf("parse recipient: %w", err)
-	}
-	fromAddr := from
-	if s.cfg.FromName != "" {
-		fromAddr = (&stdmail.Address{Name: s.cfg.FromName, Address: from}).String()
-	}
-	addr := fmt.Sprintf("%s:%d", s.cfg.Host, s.cfg.Port)
-	var d net.Dialer
-	d.Timeout = s.cfg.Timeout
-	conn, err := d.DialContext(ctx, "tcp", addr)
-	if err != nil {
-		return fmt.Errorf("dial smtp: %w", err)
-	}
-	defer conn.Close()
-
-	mode := strings.ToLower(strings.TrimSpace(s.cfg.TLSMode))
-	var c *smtp.Client
-	if mode == "tls" {
-		tlsConn := tls.Client(conn, &tls.Config{ServerName: s.cfg.Host, MinVersion: tls.VersionTLS12})
-		if err := tlsConn.HandshakeContext(ctx); err != nil {
-			return fmt.Errorf("smtp tls handshake: %w", err)
-		}
-		c, err = smtp.NewClient(tlsConn, s.cfg.Host)
-	} else {
-		c, err = smtp.NewClient(conn, s.cfg.Host)
-	}
-	if err != nil {
-		return fmt.Errorf("new smtp client: %w", err)
-	}
-	defer c.Close()
-	if mode == "starttls" {
-		if ok, _ := c.Extension("STARTTLS"); ok {
-			if err := c.StartTLS(&tls.Config{ServerName: s.cfg.Host, MinVersion: tls.VersionTLS12}); err != nil {
-				return fmt.Errorf("smtp starttls: %w", err)
-			}
-		} else {
-			return fmt.Errorf("smtp server does not support STARTTLS")
-		}
-	}
-	if s.cfg.Username != "" {
-		if err := c.Auth(smtp.PlainAuth("", s.cfg.Username, s.cfg.Password, s.cfg.Host)); err != nil {
-			return fmt.Errorf("smtp auth: %w", err)
-		}
-	}
-	if err := c.Mail(from); err != nil {
-		return fmt.Errorf("smtp mail from: %w", err)
-	}
-	if err := c.Rcpt(to); err != nil {
-		return fmt.Errorf("smtp rcpt: %w", err)
-	}
-	w, err := c.Data()
-	if err != nil {
-		return fmt.Errorf("smtp data: %w", err)
-	}
-	msg := buildMessage(fromAddr, to, subject, body)
-	if _, err := w.Write(msg); err != nil {
-		_ = w.Close()
-		return fmt.Errorf("smtp write: %w", err)
-	}
-	if err := w.Close(); err != nil {
-		return fmt.Errorf("smtp close data: %w", err)
-	}
-	return c.Quit()
-}
-
-func buildMessage(from, to, subject, body string) []byte {
-	var b bytes.Buffer
-	b.WriteString("From: " + from + "\r\n")
-	b.WriteString("To: " + to + "\r\n")
-	b.WriteString("Subject: " + mime.QEncoding.Encode("utf-8", subject) + "\r\n")
-	b.WriteString("MIME-Version: 1.0\r\n")
-	b.WriteString("Content-Type: text/plain; charset=utf-8\r\n")
-	b.WriteString("Content-Transfer-Encoding: 8bit\r\n")
-	b.WriteString("\r\n")
-	b.WriteString(body)
-	return b.Bytes()
-}
-
-func humanTTL(ttl time.Duration) string {
-	if ttl <= 0 {
-		return "a short time"
-	}
-	if ttl%time.Minute == 0 {
-		minutes := int(ttl / time.Minute)
-		if minutes == 1 {
-			return "1 minute"
-		}
-		return fmt.Sprintf("%d minutes", minutes)
-	}
-	return ttl.String()
-}