#!/bin/bash

# 使用 dig 命令查询 DNS 记录并写入 ip.txt
dig cf.youoffer.net A +short > ip.txt

# 创建一个新的文件 ip_use.txt
touch ip_use.txt

# 读取 ip.txt 中的每个 IP 地址
while IFS= read -r ip
do
    # 使用 ping 命令检查延迟
    ping_result=$(ping -c 1 -W 1 "$ip" | grep ttl)
  
    # 如果 ping 成功
    if [ $? -eq 0 ]; then
        # 提取延迟时间
        ping_time=$(echo "$ping_result" | cut -d'=' -f 4 | cut -d' ' -f 1)
    
        # 如果延迟时间小于 150ms
        if (( $(echo "$ping_time < 150" | bc -l) )); then
            # 检查 IP 地址与 Cloudflare 的连通性
            status_code=$(curl --resolve cloudflare.com:443:$ip --insecure https://cloudflare.com/cdn-cgi/trace -o /dev/null -w '%{http_code}' -s)
            
            # 如果 HTTP 状态码为 200
            if [ $status_code -eq 200 ]; then
                echo "Ping to $ip successful with a latency of $ping_time ms"
                # 将小于 150ms 的 IP 写入 ip_use.txt
                echo "$ip" >> ip_use.txt
            else
                echo "Ping to $ip discarded due to connectivity issues with Cloudflare"
            fi
        else
            echo "Ping to $ip discarded due to high latency of $ping_time ms"
        fi
    else
        echo "Ping to $ip failed"
    fi
done < ip.txt

# 读取 ip_use.txt 中的每个 IP 地址进行下载测试
while IFS= read -r ip
do
    echo "Starting download test for $ip"
    # 使用 curl 命令进行下载测试
    start_time=$(date +%s.%N)
    curl -s --resolve speed.cloudflare.com:443:"$ip" https://speed.cloudflare.com/__down?bytes=100000000 -o /dev/null --connect-timeout 5
    curl_status=$?
    end_time=$(date +%s.%N)
    elapsed_time=$(echo "$end_time - $start_time" | bc)
    
    # 检查 curl 命令的返回状态
    if [ $curl_status -eq 0 ]; then
        # 计算下载速度
        download_speed=$(echo "scale=2; (100000000*8)/(($elapsed_time)*1000000)" | bc)
        
        # 如果下载速度小于 50Mbps
        if (( $(echo "$download_speed < 50" | bc -l) )); then
            # 从 ip_use.txt 删除下载速度小于 50Mbps 的 IP
            sed -i "/$ip/d" ip_use.txt
        else
            echo "$ip has a download speed of $download_speed Mbps"
        fi
    else
        echo "Download test for $ip failed with status $curl_status"
    fi
    echo "Finished download test for $ip"
done < ip_use.txt