package parser

import (
	"regexp"
	"strings"
	"watch-tool/models"
)

type RegexLogParser struct {
	Pattern  *regexp.Regexp
	Fields   map[string]string
	Toolname string
	Hostname string
}

func (p *RegexLogParser) Parse(line string) (models.LogMessage, error) {
	entry := models.LogMessage{Type: "log_entry"}
	entry.Tool = p.Toolname
	entry.Raw = line
	entry.Host = p.Hostname

	fields := p.parseWithPattern(line)
	if fields != nil {
		entry.Fields = fields
	} else {
		entry.LogMessage = strings.TrimSpace(line)
	}

	return entry, nil
}

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
}