refactor: use parser package for file monitor

file_monitor.go

@@ -5,49 +5,44 @@ import (
 	"fmt"
 	"log/slog"
 	"regexp"
-	"strconv"
 	"strings"
-	"tixel_watch/helpers"
 	"tixel_watch/models"
+	"tixel_watch/parser"
 
 	"github.com/hpcloud/tail"
 )
 
 type FileMonitor struct {
 	config ToolConfig
-	parser LogParser
-}
-
-type LogParser interface {
-	Parse(line string, toolName string) models.LogMessage
+	parser parser.Parser
 }
 
 func NewFileMonitor(config ToolConfig) *FileMonitor {
-	var parser LogParser
+	var logParser parser.Parser
 
 	if config.Format.Pattern != "" {
 		pattern, err := regexp.Compile(config.Format.Pattern)
 		if err != nil {
 			slog.Error("invalid regex pattern", "tool", config.Name, "error", err)
-			parser = &DefaultLogParser{}
+			logParser = &parser.DefaultParser{}
 		} else {
-			parser = &RegexLogParser{
-				pattern: pattern,
-				fields:  config.Format.Fields,
+			logParser = &parser.RegexLogParser{
+				Pattern:  pattern,
+				Fields:   config.Format.Fields,
+				Toolname: config.Name,
 			}
 		}
 	} else {
-		switch config.Name {
-		case "nginx-tjm":
-			parser = &NginxTJMLogParser{}
-		default:
-			parser = &DefaultLogParser{}
+		var err error
+		logParser, err = parser.New(config.Name, "custom")
+		if err != nil {
+			slog.Error("cannot get tool specific parser", "error", err)
 		}
 	}
 
 	return &FileMonitor{
 		config: config,
-		parser: parser,
+		parser: logParser,
 	}
 }
 
@@ -85,7 +80,10 @@ func (fm *FileMonitor) Start(ctx context.Context, out chan<- models.LogMessage)
 				continue
 			}
 
-			entry := fm.parser.Parse(line.Text, fm.config.Name)
+			entry, err := fm.parser.Parse(line.Text)
+			if err != nil {
+				slog.Error("error parsing log line", "error", err)
+			}
 
 			select {
 			case out <- entry:
@@ -97,117 +95,3 @@ func (fm *FileMonitor) Start(ctx context.Context, out chan<- models.LogMessage)
 		}
 	}
 }
-
-type DefaultLogParser struct{}
-
-func (p *DefaultLogParser) Parse(line string, toolName string) models.LogMessage {
-	entry := models.NewLogMessage("log_entry", hostname)
-	entry.Tool = toolName
-	entry.LogMessage = strings.TrimSpace(line)
-	entry.Raw = line
-	return entry
-}
-
-type RegexLogParser struct {
-	pattern *regexp.Regexp
-	fields  map[string]string
-}
-
-func (p *RegexLogParser) Parse(line string, toolName string) models.LogMessage {
-	entry := models.NewLogMessage("log_entry", hostname)
-	entry.Tool = toolName
-	entry.Raw = line
-
-	fields := p.parseWithPattern(line)
-	if fields != nil {
-		entry.Fields = fields
-	} else {
-		entry.LogMessage = strings.TrimSpace(line)
-	}
-
-	return entry
-}
-
-func (p *RegexLogParser) parseWithPattern(text string) map[string]any {
-	matches := p.pattern.FindStringSubmatch(text)
-	if matches == nil {
-		return nil
-	}
-
-	fields := make(map[string]any)
-	subexpNames := p.pattern.SubexpNames()
-
-	for i, match := range matches {
-		if i == 0 {
-			continue
-		}
-
-		if i < len(subexpNames) && subexpNames[i] != "" {
-			fieldName := subexpNames[i]
-
-			if mappedName, exists := p.fields[fieldName]; exists {
-				fieldName = mappedName
-			}
-
-			fields[fieldName] = match
-		}
-	}
-
-	return fields
-}
-
-type NginxTJMLogParser struct{}
-
-func (p *NginxTJMLogParser) Parse(line string, toolName string) models.LogMessage {
-	entry := models.NewLogMessage("log_entry", hostname)
-	entry.Tool = toolName
-	entry.Raw = line
-	entry = p.parseNginxTJM(entry)
-	return entry
-}
-
-func (p *NginxTJMLogParser) parseNginxTJM(entry models.LogMessage) models.LogMessage {
-	newEntry := entry
-	var nginxBase models.NGinXBaseInfo
-	parts := strings.Fields(entry.Raw)
-	if len(parts) < 10 {
-		return newEntry
-	}
-
-	if len(parts) > 0 {
-		timestampStr := strings.Trim(parts[0], "[]")
-		timestamp, err := helpers.ParseRFC3339WithOptionalZ(timestampStr)
-		if err != nil {
-			slog.Error("unable to parse time", "error", err)
-		}
-		newEntry.Timestamp = timestamp
-	}
-
-	if len(parts) > 2 {
-		nginxBase.ClientIP = parts[2]
-	}
-
-	for i, part := range parts {
-		if strings.HasPrefix(part, "\"") {
-			if i+1 < len(parts) {
-				nginxBase.HTTPMethod = strings.Trim(part, "\"")
-				nginxBase.Route = parts[i+1]
-			}
-			break
-		}
-	}
-
-	for _, part := range parts {
-		if after, ok := strings.CutPrefix(part, "status="); ok {
-			statusCode, err := strconv.ParseInt(after, 10, 64)
-			if err != nil {
-				slog.Error("cant convert statuscode", "error", err)
-			}
-			nginxBase.StatusCode = int(statusCode)
-			break
-		}
-	}
-	newEntry.ServiceInformation = nginxBase
-
-	return newEntry
-}