package fetchers

import (

"bufio"

"bytes"

"encoding/csv"

"fmt"

"io"

"net/http"

"strings"

)

// AliyunFetcher implements the IPRangeFetcher interface for Alibaba Cloud (Aliyun).

type AliyunFetcher struct{}

func (f AliyunFetcher) Name() string {

return "aliyun"

}

func (f AliyunFetcher) Description() string {

return "Fetches IP ranges for Alibaba Cloud (Aliyun) services."

}

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

const aliyunURL = "https://cdn.jsdelivr.net/gh/sakib-m/IP-Prefix-List@main/ALIBABA/only_ip_blocks.txt"

resp, err := http.Get(aliyunURL)

if err != nil {

return nil, fmt.Errorf("failed to fetch Alibaba Cloud IP ranges: %v", err)

}

defer resp.Body.Close()

if resp.StatusCode != http.StatusOK {

return nil, fmt.Errorf("received non-200 status code from Alibaba Cloud IP list: %d", resp.StatusCode)

}

// Pre-process the data to remove comment lines

var dataBuffer bytes.Buffer

scanner := bufio.NewScanner(resp.Body)

for scanner.Scan() {

line := scanner.Text()

if !strings.HasPrefix(line, "#") {

dataBuffer.WriteString(line + "\n")

}

}

if err := scanner.Err(); err != nil {

return nil, fmt.Errorf("error reading Alibaba Cloud data: %v", err)

}

// Configure a flexible CSV reader

reader := csv.NewReader(&dataBuffer)

reader.FieldsPerRecord = -1 // Allow variable number of fields

reader.TrimLeadingSpace = true

reader.LazyQuotes = true // Be flexible with quoting

reader.Comment = '#' // Skip comment lines (as additional protection)

// Preallocate the slice with an estimated size

ipRanges := make([]string, 0, 1700)

for {

record, err := reader.Read()

if err == io.EOF {

break

}

if err != nil {

return nil, fmt.Errorf("error parsing Alibaba Cloud CSV data: %v", err)

}

// Extract the IP range from the first field if available

if len(record) > 0 && record[0] != "" {

ipRange := strings.TrimSpace(record[0])

if ipRange != "" {

ipRanges = append(ipRanges, ipRange)

}

}

}

return ipRanges, nil

}