email kinda working

2026-03-30 22:18:58 +02:00
parent 057ba02865
commit ce78c6e07f
6 changed files with 375 additions and 3 deletions
--- a/internal/backend/email.go
+++ b/internal/backend/email.go
@@ -0,0 +1,119 @@
+package backend
+
+import (
+	"bytes"
+	"crypto/tls"
+	"fmt"
+	"log"
+	"net/smtp"
+	"net/url"
+	"strings"
+
+	"github.com/emersion/go-ical"
+)
+
+// sendInvitation sends an iMIP (RFC 6047) invitation email.
+// It includes a plain-text fallback and a METHOD:REQUEST iCalendar attachment
+// that calendar clients (Thunderbird, Apple, etc.) will recognize.
+func (b *DBBackend) sendInvitation(senderName, recipientEmail, summary, description, start, end, objectPath, originalICS string) error {
+	fromAddr := fmt.Sprintf("%s@%s", senderName, b.emailDomain)
+	if b.smtp.User != "" {
+		fromAddr = b.smtp.User
+	}
+	fromHeader := fmt.Sprintf("%s <%s>", senderName, fromAddr)
+	
+	baseURL := strings.TrimSuffix(b.publicURL, "/")
+	acceptURL := fmt.Sprintf("%s/respond?path=%s&attendee=%s&status=ACCEPTED", baseURL, url.QueryEscape(objectPath), url.QueryEscape(recipientEmail))
+	declineURL := fmt.Sprintf("%s/respond?path=%s&attendee=%s&status=DECLINED", baseURL, url.QueryEscape(objectPath), url.QueryEscape(recipientEmail))
+
+	// 1. Prepare plain-text fallback - with prominent links
+	textPart := "PLEASE RESPOND TO THIS INVITATION:\r\n"
+	textPart += fmt.Sprintf("✅ ACCEPT:  %s\r\n", acceptURL)
+	textPart += fmt.Sprintf("❌ DECLINE: %s\r\n", declineURL)
+	textPart += "\r\n------------------------------------------\r\n\r\n"
+	textPart += fmt.Sprintf("You have been invited to an event by %s.\r\n\r\n", senderName)
+	textPart += fmt.Sprintf("Event: %s\r\n", summary)
+
+	// 2. Prepare iCalendar part with METHOD:REQUEST
+	var icsContent string
+	calendar, err := ical.NewDecoder(strings.NewReader(originalICS)).Decode()
+	if err == nil {
+		calendar.Props.SetText("METHOD", "REQUEST")
+		// Discourage clients from sending their own response emails
+		for _, event := range calendar.Events() {
+			for _, attendee := range event.Props["ATTENDEE"] {
+				attendee.Params.Set("RSVP", "FALSE")
+			}
+		}
+		var buf bytes.Buffer
+		if err := ical.NewEncoder(&buf).Encode(calendar); err == nil {
+			icsContent = buf.String()
+		}
+	}
+	if icsContent == "" {
+		icsContent = originalICS // Fallback to raw if decoding failed
+	}
+
+	// 3. Construct Multipart MIME Email
+	boundary := "nxcaldav_invite_boundary"
+	subject := fmt.Sprintf("Invitation: %s", summary)
+	
+	header := fmt.Sprintf("Subject: %s\r\n", subject)
+	header += fmt.Sprintf("From: %s\r\n", fromHeader)
+	header += fmt.Sprintf("To: %s\r\n", recipientEmail)
+	header += "MIME-Version: 1.0\r\n"
+	header += fmt.Sprintf("Content-Type: multipart/mixed; boundary=\"%s\"\r\n", boundary)
+	header += "\r\n"
+
+	body := fmt.Sprintf("--%s\r\n", boundary)
+	body += "Content-Type: text/plain; charset=UTF-8\r\n"
+	body += "Content-Transfer-Encoding: 7bit\r\n"
+	body += "\r\n"
+	body += textPart + "\r\n"
+
+	body += fmt.Sprintf("--%s\r\n", boundary)
+	body += "Content-Type: text/calendar; method=REQUEST; charset=UTF-8\r\n"
+	body += "Content-Transfer-Encoding: 7bit\r\n"
+	body += "\r\n"
+	body += icsContent + "\r\n"
+	body += fmt.Sprintf("--%s--\r\n", boundary)
+
+	// 4. Send the mail
+	addr := fmt.Sprintf("%s:%d", b.smtp.Host, b.smtp.Port)
+	tlsConfig := &tls.Config{InsecureSkipVerify: true, ServerName: b.smtp.Host}
+	
+	var c *smtp.Client
+	if b.smtp.Port == 465 {
+		conn, err := tls.Dial("tcp", addr, tlsConfig)
+		if err != nil { return err }
+		c, err = smtp.NewClient(conn, b.smtp.Host)
+	} else {
+		c, err = smtp.Dial(addr)
+	}
+	if err != nil { return err }
+	defer c.Close()
+
+	if err = c.Hello("localhost"); err != nil { return err }
+	if b.smtp.Port != 465 {
+		if ok, _ := c.Extension("STARTTLS"); ok {
+			if err = c.StartTLS(tlsConfig); err != nil { return err }
+		}
+	}
+	if b.smtp.User != "" && b.smtp.Password != "" {
+		auth := smtp.PlainAuth("", b.smtp.User, b.smtp.Password, b.smtp.Host)
+		if err = c.Auth(auth); err != nil { return err }
+	}
+
+	if err = c.Mail(fromAddr); err != nil { return err }
+	if err = c.Rcpt(recipientEmail); err != nil { return err }
+
+	w, err := c.Data()
+	if err != nil { return err }
+	_, err = w.Write([]byte(header + body))
+	if err != nil { return err }
+	err = w.Close()
+	if err != nil { return err }
+
+	log.Printf("[email] Successfully sent iMIP invitation to %s", recipientEmail)
+	return c.Quit()
+}