package fetchers

import (

"fmt"

"io"

"net/http"

"strconv"

"strings"

)

// ASNFetcher implements the IPRangeFetcher interface for specific ASNs.

type ASNFetcher struct {

ASNs []string // List of ASNs in AS#### format

}

func (f ASNFetcher) Name() string {

return "asn"

}

func (f ASNFetcher) Description() string {

return "Fetches IP ranges for specific Autonomous System Numbers (ASNs)."

}

func (f ASNFetcher) FetchIPRanges() ([]string, error) {

if len(f.ASNs) == 0 {

return nil, fmt.Errorf("no ASNs provided to fetch")

}

ipRanges := make([]string, 0)

for _, asn := range f.ASNs {

url := fmt.Sprintf("https://api.hackertarget.com/aslookup/?q=%s", asn)

resp, err := http.Get(url) // #nosec:disable G107 -- False positive

if err != nil {

return nil, fmt.Errorf("failed to fetch IP ranges for ASN %s: %v", asn, err)

}

if resp.StatusCode != http.StatusOK {

return nil, fmt.Errorf("received non-200 status code %d for ASN %s", resp.StatusCode, asn)

}

body, err := io.ReadAll(resp.Body)

defer resp.Body.Close()

if err != nil {

return nil, fmt.Errorf("failed to read response body for ASN %s: %v", asn, err)

}

// Split the response by newlines

lines := strings.Split(string(body), "\n")

// Skip the first line as it contains the ASN info rather than IP ranges

if len(lines) > 1 {

for i := 1; i < len(lines); i++ {

ipRange := strings.TrimSpace(lines[i])

if ipRange != "" {

ipRanges = append(ipRanges, ipRange)

}

}

}

}

return ipRanges, nil

}

// NewASNFetcher creates a new ASNFetcher with the specified ASNs.

func NewASNFetcher(asns []string) *ASNFetcher {

// validate ASNs

if len(asns) == 0 {

return nil

}

for _, asn := range asns {

if !strings.HasPrefix(asn, "AS") {

panic(fmt.Sprintf("invalid ASN: %s. It must start with 'AS'.", asn))

}

// check if the remainder is a number

if _, err := strconv.Atoi(asn[2:]); err != nil {

panic(fmt.Sprintf("invalid ASN: %s. The part after 'AS' is not a number.", asn))

}

}

return &ASNFetcher{

ASNs: asns,

}

}