move up

email.go

@@ -0,0 +1,176 @@
+package contact
+
+import (
+	"crypto/tls"
+	"fmt"
+	"log"
+	"net/mail"
+	"net/smtp"
+	"os"
+	"strings"
+
+	"github.com/bytbox/go-pop3"
+	"github.com/emersion/go-imap"
+	"github.com/emersion/go-imap/client"
+)
+
+type Emailer struct {
+	From     string
+	SMTP     string
+	POP3     string
+	IMAP     string
+	Password string
+	Limit    int
+}
+
+func NewEmailer() *Emailer {
+	envOr := func(key, def string) string {
+		if v, ok := os.LookupEnv(strings.ToUpper(key)); ok {
+			return v
+		}
+		return def
+	}
+	return &Emailer{
+		From:     envOr("FROM", "breellocaldev@gmail.com"),
+		SMTP:     envOr("SMTP", "smtp.gmail.com:465"),
+		Password: envOr("PASSWORD", "lhnjijrvqaesiufp"),
+	}
+}
+
+func (e *Emailer) Read() (chan *mail.Message, error) {
+	return e.ReadIMAP()
+}
+
+func (e *Emailer) ReadIMAP() (chan *mail.Message, error) {
+	c, err := client.DialTLS(e.IMAP, nil)
+	if err != nil {
+		return nil, err
+	}
+	if err := c.Login(e.From, e.Password); err != nil {
+		return nil, err
+	}
+	mbox, err := c.Select("INBOX", true) //readonly
+	if err != nil {
+		return nil, err
+	}
+	from := uint32(1)
+	to := mbox.Messages
+	if e.Limit > 0 && to > uint32(e.Limit) {
+		from = to - uint32(e.Limit-1)
+	}
+	seqset := new(imap.SeqSet)
+	seqset.AddRange(from, to)
+	emails := make(chan *mail.Message)
+	messages := make(chan *imap.Message)
+	go func() {
+		defer c.Logout()
+		section := &imap.BodySectionName{}
+		if err := c.Fetch(seqset, []imap.FetchItem{imap.FetchEnvelope, section.FetchItem()}, messages); err != nil {
+			log.Println("error fetching:", err)
+		}
+	}()
+	go func() {
+		defer close(emails)
+		for msg := range messages {
+			for _, v := range msg.Body {
+				m, err := mail.ReadMessage(v)
+				if err != nil {
+					log.Println(err)
+				} else {
+					emails <- m
+				}
+			}
+		}
+	}()
+	return emails, nil
+}
+
+func (e *Emailer) ReadPOP3() (chan *mail.Message, error) {
+	emails := []*mail.Message{}
+	c, err := pop3.DialTLS(e.POP3)
+	if err != nil {
+		return nil, err
+	}
+	defer c.Rset()
+	if err := c.Auth(e.From, e.Password); err != nil {
+		return nil, err
+	}
+	ids, _, err := c.ListAll()
+	if err != nil {
+		return nil, err
+	}
+	for j, id := range ids {
+		if e.Limit > 0 && len(ids)-1-j >= e.Limit {
+			break
+		}
+		raw, err := c.Retr(id)
+		if err != nil {
+			return nil, err
+		}
+		msg, err := mail.ReadMessage(strings.NewReader(raw))
+		if err != nil {
+			return nil, err
+		}
+		emails = append(emails, msg)
+	}
+	return nil, nil
+	//return emails, nil //c.Quit()
+}
+
+func (e *Emailer) Send(to, subj, msg string) error {
+	headers := e.headers(to, e.From, subj)
+	body := e.body(headers, msg)
+	smtp, err := e.smtp()
+	if err != nil {
+		return err
+	}
+	defer smtp.Quit()
+	if err := smtp.Mail(e.From); err != nil {
+		return err
+	}
+	if err := smtp.Rcpt(to); err != nil {
+		return err
+	}
+	w, err := smtp.Data()
+	if err != nil {
+		return err
+	}
+	if _, err := w.Write([]byte(body)); err != nil {
+		return err
+	}
+	return w.Close()
+}
+
+func (e *Emailer) headers(to, from, subj string) map[string]string {
+	return map[string]string{
+		"To":      to,
+		"From":    from,
+		"Subject": subj,
+	}
+}
+
+func (e *Emailer) body(headers map[string]string, body string) string {
+	b := ""
+	for k, v := range headers {
+		b += fmt.Sprintf("%s: %s\r\n", k, v)
+	}
+	return b + "\r\n" + body
+}
+
+func (e *Emailer) smtp() (*smtp.Client, error) {
+	host := strings.Split(e.SMTP, ":")[0]
+	auth := smtp.PlainAuth("", e.From, e.Password, host)
+	tlsconfig := &tls.Config{ServerName: host}
+	conn, err := tls.Dial("tcp", e.SMTP, tlsconfig)
+	if err != nil {
+		return nil, fmt.Errorf("cannot dial %v: %v", e.SMTP, err)
+	}
+	smtp, err := smtp.NewClient(conn, host)
+	if err != nil {
+		return nil, fmt.Errorf("cannot new client %v: %v", host, err)
+	}
+	if err := smtp.Auth(auth); err != nil {
+		return nil, fmt.Errorf("cannot auth client: %v", err)
+	}
+	return smtp, nil
+}