package notifications
import (
"fmt"
"log"
"net/smtp"
"strings"
)
type SMTPConfig struct {
Host string
Port int
Username string
Password string
From string
}
func (c *SMTPConfig) IsConfigured() bool {
return c.Host != "" && c.From != ""
}
func (c *SMTPConfig) addr() string {
return fmt.Sprintf("%s:%d", c.Host, c.Port)
}
func SendEmailNotification(cfg SMTPConfig, toEmail, message string, meta AlertMetadata) (bool, error) {
if !cfg.IsConfigured() {
return false, fmt.Errorf("SMTP is not configured")
}
subject := fmt.Sprintf("Koin Ping Alert: %s", humanAlertType(meta.AlertType))
body := buildEmailBody(message, meta)
msg := strings.Join([]string{
fmt.Sprintf("From: %s", cfg.From),
fmt.Sprintf("To: %s", toEmail),
fmt.Sprintf("Subject: %s", subject),
"MIME-Version: 1.0",
"Content-Type: text/html; charset=UTF-8",
"",
body,
}, "\r\n")
var auth smtp.Auth
if cfg.Username != "" {
auth = smtp.PlainAuth("", cfg.Username, cfg.Password, cfg.Host)
}
err := smtp.SendMail(cfg.addr(), auth, cfg.From, []string{toEmail}, []byte(msg))
if err != nil {
log.Printf("Failed to send email notification to %s: %v", toEmail, err)
return false, err
}
return true, nil
}
func TestEmailNotification(cfg SMTPConfig, toEmail string) (bool, error) {
meta := AlertMetadata{AlertType: "test"}
return SendEmailNotification(cfg, toEmail,
"This is a test notification from Koin Ping. Your email is configured correctly!", meta)
}
func buildEmailBody(message string, meta AlertMetadata) string {
txSection := ""
if meta.TxHash != "" {
txSection = fmt.Sprintf(
`| Transaction | `+
`View on Etherscan |
`,
meta.TxHash,
)
}
return fmt.Sprintf(`
Koin Ping Alert
%s
| Address | %s |
| Blockchain Address | %s |
%s
Sent by Koin Ping
`, message, meta.AddressLabel, meta.Address, txSection)
}
func humanAlertType(alertType string) string {
switch alertType {
case "incoming_tx":
return "Incoming Transaction"
case "outgoing_tx":
return "Outgoing Transaction"
case "large_transfer":
return "Large Transfer"
case "balance_below":
return "Balance Below Threshold"
default:
return "Alert"
}
}