2 files changed, 101 insertions, 0 deletions
diff --git a/internal/notifier/email.go b/internal/notifier/email.go
new file mode 100644
index 0000000..4ce8d69
--- /dev/null
+++ b/internal/notifier/email.go
@@ -0,0 +1,41 @@
+package notifier
+
+import (
+	"fmt"
+	"log"
+	"net/smtp"
+
+	"codeberg.org/snonux/gorum/internal/config"
+)
+
+func emailNotify(conf config.Config, subject, body string) error {
+	if !conf.EmailNotifycationEnabled() {
+		return nil
+	}
+	log.Println("notify:", subject, body)
+
+	headers := map[string]string{
+		"From":         conf.EmailFrom,
+		"To":           conf.EmailTo,
+		"Subject":      subject,
+		"MIME-Version": "1.0",
+		"Content-Type": "text/plain; charset=\"utf-8\"",
+	}
+
+	header := ""
+	for k, v := range headers {
+		header += fmt.Sprintf("%s: %s\r\n", k, v)
+	}
+
+	message := header + "\r\n" + body
+	log.Println("Using SMTP server", conf.SMTPServer)
+
+	return smtp.SendMail(conf.SMTPServer, nil, conf.EmailFrom,
+		[]string{conf.EmailTo}, []byte(message))
+}
+
+func emailNotifyError(conf config.Config, err error) {
+	if err := emailNotify(conf, fmt.Sprintf("GORUM: An error occured: %v", err), err.Error()); err != nil {
+		log.Println("error:", err)
+	}
+}
diff --git a/internal/notifier/notifier.go b/internal/notifier/notifier.go
new file mode 100644
index 0000000..24447a9
--- /dev/null
+++ b/internal/notifier/notifier.go
@@ -0,0 +1,60 @@
+package notifier
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	"codeberg.org/snonux/gorum/internal/config"
+)
+
+type Notifier struct{}
+
+func New() Notifier {
+	return Notifier{}
+}
+
+func (notifier Notifier) Start(ctx context.Context, conf config.Config, scoreCh <-chan string) {
+	go func() {
+		for scoresStr := range scoreCh {
+			if err := notifier.persist(conf, scoresStr); err != nil {
+				emailNotifyError(conf, err)
+			}
+		}
+	}()
+}
+
+func (notifier Notifier) persist(conf config.Config, scoresStr string) error {
+	if err := emailNotify(conf, "GORUM: Quorum changed", scoresStr); err != nil {
+		return err
+	}
+
+	if _, err := os.Stat(conf.StateDir); os.IsNotExist(err) {
+		if err := os.MkdirAll(conf.StateDir, 0755); err != nil {
+			return err
+		}
+	}
+
+	return writeFileViaTmp(fmt.Sprintf("%s/%s", conf.StateDir, conf.ScoreFile), scoresStr)
+}
+
+// Create tmp file first, and then, once written, rename it.
+func writeFileViaTmp(filePath, content string) error {
+	tmpFilePath := fmt.Sprintf("%s.tmp", filePath)
+
+	fd, err := os.Create(tmpFilePath)
+	if err != nil {
+		return err
+	}
+	defer fd.Close()
+
+	if _, err := fd.WriteString(content); err != nil {
+		return err
+	}
+
+	if err := fd.Sync(); err != nil {
+		return err
+	}
+
+	return os.Rename(tmpFilePath, filePath)
+}