feat: add Docker deployment and Microsoft OAuth support

mengpost-backend/services/smtp_oauth.go

@@ -0,0 +1,73 @@
+package services
+
+import (
+	"bytes"
+	"context"
+	"crypto/tls"
+	"fmt"
+
+	smtpp "github.com/emersion/go-smtp"
+	"gopkg.in/gomail.v2"
+
+	"mengpost-backend/models"
+)
+
+// sendMailMicrosoftOAuth 使用 XOAUTH2 + STARTTLS 连接 smtp.office365.com:587.
+func sendMailMicrosoftOAuth(acc *models.Account, to, subject, body string, html bool) error {
+	if AppCfg == nil {
+		return fmt.Errorf("服务未配置 OAuth")
+	}
+	mt, err := RefreshMicrosoftAccess(context.Background(), AppCfg, acc.OAuthRefreshToken)
+	if err != nil {
+		return err
+	}
+	if mt.RefreshToken != "" {
+		_ = models.UpdateAccountOAuthRefresh(acc.ID, mt.RefreshToken)
+	}
+
+	m := gomail.NewMessage()
+	m.SetHeader("From", acc.Email)
+	m.SetHeader("To", to)
+	m.SetHeader("Subject", subject)
+	if html {
+		m.SetBody("text/html", body)
+	} else {
+		m.SetBody("text/plain", body)
+	}
+	var buf bytes.Buffer
+	if _, err := m.WriteTo(&buf); err != nil {
+		return err
+	}
+
+	addr := fmt.Sprintf("%s:%d", acc.SMTPHost, acc.SMTPPort)
+	tlsCfg := &tls.Config{
+		MinVersion: tls.VersionTLS12,
+		ServerName: acc.SMTPHost,
+	}
+	c, err := smtpp.DialStartTLS(addr, tlsCfg)
+	if err != nil {
+		return err
+	}
+	defer c.Close()
+
+	if err := c.Auth(NewXOAUTH2Client(acc.Email, mt.AccessToken)); err != nil {
+		return err
+	}
+	if err := c.Mail(acc.Email, nil); err != nil {
+		return err
+	}
+	if err := c.Rcpt(to, nil); err != nil {
+		return err
+	}
+	w, err := c.Data()
+	if err != nil {
+		return err
+	}
+	if _, err := w.Write(buf.Bytes()); err != nil {
+		return err
+	}
+	if err := w.Close(); err != nil {
+		return err
+	}
+	return c.Quit()
+}