feat: message parser with json/regex/text modes

internal/parser/regex.go

@@ -0,0 +1,46 @@
+package parser
+
+import (
+	"fmt"
+	"regexp"
+)
+
+type RegexParser struct {
+	re *regexp.Regexp
+}
+
+func NewRegexParser(pattern string) (*RegexParser, error) {
+	re, err := regexp.Compile(pattern)
+	if err != nil {
+		return nil, fmt.Errorf("compile regex pattern: %w", err)
+	}
+	return &RegexParser{re: re}, nil
+}
+
+func (p *RegexParser) Parse(body []byte) (*ParsedMessage, error) {
+	matches := p.re.FindStringSubmatch(string(body))
+	if matches == nil {
+		return nil, fmt.Errorf("regex: body does not match pattern")
+	}
+
+	names := p.re.SubexpNames()
+	data := make(map[string]interface{})
+	var event string
+
+	for i, name := range names {
+		if i == 0 || name == "" {
+			continue
+		}
+		if name == "event" {
+			event = matches[i]
+		} else {
+			data[name] = matches[i]
+		}
+	}
+
+	return &ParsedMessage{
+		Event: event,
+		Data:  data,
+		Body:  string(body),
+	}, nil
+}