Initial backend repository commit.

Set up project files and add .gitignore to exclude local build/runtime artifacts.

Made-with: Cursor

internal/pkg/email/client.go

@@ -0,0 +1,131 @@
+package email
+
+import (
+	"context"
+	"crypto/tls"
+	"fmt"
+	"strings"
+	"time"
+
+	gomail "gopkg.in/gomail.v2"
+)
+
+// Message 发信参数
+type Message struct {
+	To          []string
+	Cc          []string
+	Bcc         []string
+	ReplyTo     []string
+	Subject     string
+	TextBody    string
+	HTMLBody    string
+	Attachments []string
+}
+
+type Client interface {
+	IsEnabled() bool
+	Config() Config
+	Send(ctx context.Context, msg Message) error
+}
+
+type clientImpl struct {
+	cfg Config
+}
+
+func NewClient(cfg Config) Client {
+	return &clientImpl{cfg: cfg}
+}
+
+func (c *clientImpl) IsEnabled() bool {
+	return c.cfg.Enabled &&
+		strings.TrimSpace(c.cfg.Host) != "" &&
+		c.cfg.Port > 0 &&
+		strings.TrimSpace(c.cfg.FromAddress) != ""
+}
+
+func (c *clientImpl) Config() Config {
+	return c.cfg
+}
+
+func (c *clientImpl) Send(ctx context.Context, msg Message) error {
+	if !c.IsEnabled() {
+		return fmt.Errorf("email client is disabled or misconfigured")
+	}
+	if len(msg.To) == 0 {
+		return fmt.Errorf("email recipient is empty")
+	}
+	if strings.TrimSpace(msg.Subject) == "" {
+		return fmt.Errorf("email subject is empty")
+	}
+	if strings.TrimSpace(msg.TextBody) == "" && strings.TrimSpace(msg.HTMLBody) == "" {
+		return fmt.Errorf("email body is empty")
+	}
+
+	m := gomail.NewMessage()
+	m.SetAddressHeader("From", c.cfg.FromAddress, c.cfg.FromName)
+	m.SetHeader("To", msg.To...)
+	if len(msg.Cc) > 0 {
+		m.SetHeader("Cc", msg.Cc...)
+	}
+	if len(msg.Bcc) > 0 {
+		m.SetHeader("Bcc", msg.Bcc...)
+	}
+	if len(msg.ReplyTo) > 0 {
+		m.SetHeader("Reply-To", msg.ReplyTo...)
+	}
+	m.SetHeader("Subject", msg.Subject)
+
+	if strings.TrimSpace(msg.TextBody) != "" && strings.TrimSpace(msg.HTMLBody) != "" {
+		m.SetBody("text/plain", msg.TextBody)
+		m.AddAlternative("text/html", msg.HTMLBody)
+	} else if strings.TrimSpace(msg.HTMLBody) != "" {
+		m.SetBody("text/html", msg.HTMLBody)
+	} else {
+		m.SetBody("text/plain", msg.TextBody)
+	}
+
+	for _, attachment := range msg.Attachments {
+		if strings.TrimSpace(attachment) == "" {
+			continue
+		}
+		m.Attach(attachment)
+	}
+
+	timeout := c.cfg.TimeoutSeconds
+	if timeout <= 0 {
+		timeout = 15
+	}
+	dialer := gomail.NewDialer(c.cfg.Host, c.cfg.Port, c.cfg.Username, c.cfg.Password)
+	if c.cfg.UseTLS {
+		dialer.TLSConfig = &tls.Config{
+			ServerName:         c.cfg.Host,
+			InsecureSkipVerify: c.cfg.InsecureSkipVerify,
+		}
+		// 465 端口通常要求直接 TLS（Implicit TLS）。
+		if c.cfg.Port == 465 {
+			dialer.SSL = true
+		}
+	}
+
+	sendCtx := ctx
+	cancel := func() {}
+	if timeout > 0 {
+		sendCtx, cancel = context.WithTimeout(ctx, time.Duration(timeout)*time.Second)
+	}
+	defer cancel()
+
+	done := make(chan error, 1)
+	go func() {
+		done <- dialer.DialAndSend(m)
+	}()
+
+	select {
+	case <-sendCtx.Done():
+		return fmt.Errorf("send email canceled: %w", sendCtx.Err())
+	case err := <-done:
+		if err != nil {
+			return fmt.Errorf("send email failed: %w", err)
+		}
+		return nil
+	}
+}