everywhere: add email notifications

api/cron_email_notification.go

@@ -0,0 +1,66 @@
+package main
+
+import (
+	"time"
+)
+
+func emailNotificationBegin() error {
+	go func() {
+		for {
+			statement := `
+				SELECT email, sendModeratorNotifications, sendReplyNotifications
+				FROM emails
+				WHERE pendingEmails > 0 AND lastEmailNotificationDate < $1;
+			`
+			rows, err := db.Query(statement, time.Now().UTC().Add(time.Duration(-10)*time.Minute))
+			if err != nil {
+				logger.Errorf("cannot query domains: %v", err)
+				return
+			}
+			defer rows.Close()
+
+			for rows.Next() {
+				var email string
+				var sendModeratorNotifications bool
+				var sendReplyNotifications bool
+				if err = rows.Scan(&email, &sendModeratorNotifications, &sendReplyNotifications); err != nil {
+					logger.Errorf("cannot scan email in cron job to send notifications: %v", err)
+					continue
+				}
+
+				if _, ok := emailQueue[email]; !ok {
+					if err = emailNotificationPendingReset(email); err != nil {
+						logger.Errorf("error resetting pendingEmails: %v", err)
+						continue
+					}
+				}
+
+				cont := true
+				kindListMap := map[string][]emailNotification{}
+				for cont {
+					select {
+					case e := <-emailQueue[email]:
+						if _, ok := kindListMap[e.Kind]; !ok {
+							kindListMap[e.Kind] = []emailNotification{}
+						}
+
+						if (e.Kind == "reply" && sendReplyNotifications) || sendModeratorNotifications {
+							kindListMap[e.Kind] = append(kindListMap[e.Kind], e)
+						}
+					default:
+						cont = false
+						break
+					}
+				}
+
+				for kind, list := range kindListMap {
+					go emailNotificationSend(email, kind, list)
+				}
+			}
+
+			time.Sleep(10 * time.Minute)
+		}
+	}()
+
+	return nil
+}