refactor: use parser package for systemd logs

helpers/helpers.go

@@ -0,0 +1,86 @@
+package helpers
+
+import (
+	"fmt"
+	"log/slog"
+	"os"
+	"regexp"
+	"strings"
+	"time"
+	"tixel_watch/models"
+)
+
+var (
+	syslogPattern = regexp.MustCompile(`^(\w{3} \d{2} \d{2}:\d{2}:\d{2}) ([^\s]+) ([^:]+):\s*(.*)$`)
+)
+
+func ExtractSyslogHeader(line string) (models.SyslogFields, string) {
+	var syslogFields models.SyslogFields
+
+	matches := syslogPattern.FindStringSubmatch(strings.TrimSpace(line))
+	if len(matches) != 5 {
+		return syslogFields, line
+	}
+
+	sysTime, err := ParseSyslogTimeToRFC3339(matches[1])
+	if err != nil {
+		slog.Error("cant parse sys log time", "error", err)
+	}
+	syslogFields.SysLogTimestamp = sysTime
+	syslogFields.Hostname = matches[2]
+	syslogFields.ProcessInfo = matches[3]
+
+	return syslogFields, matches[4]
+}
+
+func GetNamedGroup(match []string, regex *regexp.Regexp, groupName string) string {
+	names := regex.SubexpNames()
+	for i, name := range names {
+		if name == groupName && i < len(match) {
+			return match[i]
+		}
+	}
+	return ""
+}
+
+func ParseRFC3339WithOptionalZ(timeStr string) (time.Time, error) {
+	if !strings.HasSuffix(timeStr, "Z") && !strings.ContainsAny(timeStr[len(timeStr)-6:], "+-") {
+		timeStr += "Z"
+	}
+	return time.Parse(time.RFC3339Nano, timeStr)
+}
+
+var deToEnMonth = map[string]string{
+	"Jan": "Jan", "Feb": "Feb", "Mär": "Mar", "Apr": "Apr", "Mai": "May",
+	"Jun": "Jun", "Jul": "Jul", "Aug": "Aug", "Sep": "Sep", "Okt": "Oct",
+	"Nov": "Nov", "Dez": "Dec",
+}
+
+func translateMonth(syslogTime string) string {
+	for de, en := range deToEnMonth {
+		if strings.HasPrefix(syslogTime, de) {
+			return strings.Replace(syslogTime, de, en, 1)
+		}
+	}
+	return syslogTime
+}
+
+func ParseSyslogTimeToRFC3339(syslogTime string) (time.Time, error) {
+	const syslogLayout = "Jan 02 15:04:05"
+	syslogTime = translateMonth(syslogTime)
+	t, err := time.Parse(syslogLayout, syslogTime)
+	if err != nil {
+		return t, fmt.Errorf("cannot parse syslog time %q: %w", syslogTime, err)
+	}
+	now := time.Now()
+	t = t.AddDate(now.Year(), 0, 0)
+	return t, nil
+}
+
+func GetHostname() (string, error) {
+	hostname, err := os.Hostname()
+	if err != nil {
+		hostname = "unknown"
+	}
+	return hostname, nil
+}