add mail send func

pkg/mail/mail.go

@@ -0,0 +1,184 @@
+package mail
+
+import (
+	"bytes"
+	"crypto/tls"
+	"encoding/base64"
+	"fmt"
+	"io/ioutil"
+	"net"
+	"net/smtp"
+	"strings"
+	"time"
+)
+
+type Mail interface {
+	Authorize()
+	Send(message Message) error
+}
+
+type mail struct {
+	username string
+	password string
+	host     string
+	port     string
+	auth     smtp.Auth
+}
+
+type Message struct {
+	From        string
+	To          []string
+	Cc          []string
+	Bcc         []string
+	Subject     string
+	Body        string
+	ContentType string
+	Attachment  []Attachment
+}
+
+type Attachment struct {
+	Name        string
+	URL         string
+	ContentType string
+	WithFile    bool
+}
+
+// NewSendMail 构造一个邮件发送对象
+func NewSendMail(username string, password string, host string, port string) Mail {
+	return &mail{
+		username: username,
+		password: password,
+		host:     host,
+		port:     port,
+	}
+}
+
+func (m *mail) Authorize() {
+	m.auth = smtp.PlainAuth("", m.username, m.password, m.host)
+}
+
+func (m *mail) Send(message Message) error {
+	m.Authorize()
+	buffer := bytes.NewBuffer(nil)
+	boundary := "GoBoundary"
+	Header := make(map[string]string)
+	Header["From"] = message.From
+	Header["To"] = strings.Join(message.To, ";")
+	Header["Cc"] = strings.Join(message.Cc, ";")
+	Header["Bcc"] = strings.Join(message.Bcc, ";")
+	Header["Subject"] = message.Subject
+	Header["Content-Type"] = "multipart/mixed;boundary=" + boundary
+	Header["Mime-Version"] = "1.0"
+	Header["Date"] = time.Now().String()
+	m.writeHeader(buffer, Header)
+
+	body := "\r\n--" + boundary + "\r\n"
+	body += "Content-Type:" + message.ContentType + "\r\n"
+	body += "\r\n" + message.Body + "\r\n"
+	buffer.WriteString(body)
+
+	for i := 0; i < len(message.Attachment); i++ {
+		item := message.Attachment[i]
+		if item.WithFile {
+			attachment := "\r\n--" + boundary + "\r\n"
+			attachment += "Content-Transfer-Encoding:base64\r\n"
+			attachment += "Content-Disposition:attachment\r\n"
+			attachment += "Content-Type:" + item.ContentType + ";name=\"" + item.Name + "\"\r\n"
+			buffer.WriteString(attachment)
+			//defer func() {
+			//	if err := recover(); err != nil {
+			//	}
+			//}()
+			m.writeFile(buffer, item.URL)
+		}
+	}
+
+	buffer.WriteString("\r\n--" + boundary + "--")
+	//smtp.SendMail(mail.Host+":"+mail.Port, mail.Auth, message.From, message.To, buffer.Bytes())
+
+	err := sendMailUsingTLS(m.host+":"+m.port, m.auth, message.From, message.To, buffer.Bytes())
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (m *mail) writeHeader(buffer *bytes.Buffer, Header map[string]string) string {
+	header := ""
+	for key, value := range Header {
+		header += key + ":" + value + "\r\n"
+	}
+	header += "\r\n"
+	buffer.WriteString(header)
+	return header
+}
+
+// read and write the file to buffer
+func (m *mail) writeFile(buffer *bytes.Buffer, fileName string) {
+	file, err := ioutil.ReadFile(fileName)
+	if err != nil {
+		panic(err.Error())
+	}
+	payload := make([]byte, base64.StdEncoding.EncodedLen(len(file)))
+	base64.StdEncoding.Encode(payload, file)
+	buffer.WriteString("\r\n")
+	for index, line := 0, len(payload); index < line; index++ {
+		buffer.WriteByte(payload[index])
+		if (index+1)%76 == 0 {
+			buffer.WriteString("\r\n")
+		}
+	}
+}
+
+func sendMailUsingTLS(addr string, auth smtp.Auth, from string, to []string, msg []byte) (err error) {
+	c, err := dial(addr)
+	if err != nil {
+		return err
+	}
+
+	defer func(c *smtp.Client) {
+		_ = c.Close()
+	}(c)
+
+	if auth != nil {
+		if ok, _ := c.Extension("AUTH"); ok {
+			if err = c.Auth(auth); err != nil {
+				return err
+			}
+		}
+	}
+	if err = c.Mail(from); err != nil {
+		return err
+	}
+	//tos := strings.Split(to, ";")
+	for _, addr := range to {
+		if err = c.Rcpt(addr); err != nil {
+			fmt.Print(err)
+			return err
+		}
+	}
+	w, err := c.Data()
+	if err != nil {
+		return err
+	}
+	_, err = w.Write(msg)
+	if err != nil {
+		return err
+	}
+	err = w.Close()
+	if err != nil {
+		return err
+	}
+	return c.Quit()
+}
+
+func dial(addr string) (*smtp.Client, error) {
+	conn, err := tls.Dial("tcp", addr, nil)
+	if err != nil {
+		return nil, err
+	}
+	//分解主机端口字符串
+	host, _, _ := net.SplitHostPort(addr)
+	return smtp.NewClient(conn, host)
+}