package WebScan

import (
	"crypto/md5" //nolint:gosec // G501: MD5用于内容指纹识别，非加密用途
	"fmt"

	"github.com/shadow1ng/fscan/webscan/fingerprint"
)

// CheckDatas 存储HTTP响应的检查数据
type CheckDatas struct {
	Body    []byte                   // 响应体
	Headers string                   // 响应头
	Favicon fingerprint.FaviconHashes // Favicon hash（mmh3 + MD5）
}

// InfoCheck 检查URL的指纹信息
func InfoCheck(URL string, CheckData *[]CheckDatas) []string {
	var matchedInfos []string

	// 遍历检查数据
	for _, data := range *CheckData {
		// 基础指纹库：正则规则匹配 (272条)
		matchedInfos = append(matchedInfos, matchByRegex(data)...)

		// 基础指纹库：MD5指纹匹配 (30条)
		if md5Name := matchByMd5(data.Body); md5Name != "" {
			matchedInfos = append(matchedInfos, md5Name)
		}

		// 增强指纹库：FingerprintHub (3139条)
		// 支持favicon hash、多种matcher类型、更丰富的匹配规则
		enhanced := fingerprint.MatchEnhancedFingerprints(data.Body, data.Headers, data.Favicon)
		matchedInfos = append(matchedInfos, enhanced...)

		// 版本提取：从响应中提取软件版本信息
		versions := fingerprint.ExtractVersions(string(data.Body), data.Headers)
		for _, v := range versions {
			matchedInfos = append(matchedInfos, fmt.Sprintf("%s/%s", v.Name, v.Version))
		}
	}

	// 去重处理
	matchedInfos = removeDuplicateElement(matchedInfos)

	// 指纹信息已在 WebTitle 日志中统一输出，此处不再单独输出

	return matchedInfos
}

// matchByRegex 使用正则规则匹配指纹
func matchByRegex(data CheckDatas) []string {
	var matched []string

	for _, rule := range fingerprint.RuleDatas {
		// 跳过编译失败的规则
		if rule.Compiled == nil {
			continue
		}

		// 根据规则类型选择匹配内容
		var isMatch bool
		switch rule.Type {
		case "code":
			isMatch = rule.Compiled.MatchString(string(data.Body))
		default:
			isMatch = rule.Compiled.MatchString(data.Headers)
		}

		if isMatch {
			matched = append(matched, rule.Name)
		}
	}

	return matched
}

// matchByMd5 使用MD5指纹匹配
func matchByMd5(body []byte) string {
	//nolint:gosec // G401: MD5用于内容指纹，非加密用途
	contentMd5 := fmt.Sprintf("%x", md5.Sum(body))

	for _, md5Info := range fingerprint.Md5Datas {
		if contentMd5 == md5Info.Md5Str {
			return md5Info.Name
		}
	}

	return ""
}

// removeDuplicateElement 移除切片中的重复元素
func removeDuplicateElement(items []string) []string {
	// 预分配空间
	result := make([]string, 0, len(items))
	seen := make(map[string]struct{}, len(items))

	// 使用map去重
	for _, item := range items {
		if _, exists := seen[item]; !exists {
			seen[item] = struct{}{}
			result = append(result, item)
		}
	}

	return result
}