#!/bin/bash
PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin
export PATH
export LANG=en_US.UTF-8
export LANGUAGE=en_US:en

get_node_url(){
	nodes=(http://183.235.223.101:3389 http://125.88.182.172:5880 http://128.1.164.196 http://103.224.251.67 http://download.bt.cn);
	i=1;
	for node in ${nodes[@]};
	do
		start=`date +%s.%N`
		result=`curl -sS --connect-timeout 3 -m 60 $node/check.txt`
		if [ "$result" = 'True' ];then
			end=`date +%s.%N`
			start_s=`echo $start | cut -d '.' -f 1`
			start_ns=`echo $start | cut -d '.' -f 2`
			end_s=`echo $end | cut -d '.' -f 1`
			end_ns=`echo $end | cut -d '.' -f 2`
			time_micro=$(( (10#$end_s-10#$start_s)*1000000 + (10#$end_ns/1000 - 10#$start_ns/1000) ))
			time_ms=$(($time_micro/1000))
			values[$i]=$time_ms;
			urls[$time_ms]=$node
			i=$(($i+1))
			if [ $time_ms -lt 50 ];then
				break;
			fi
		fi
	done
	j=5000
	for n in ${values[@]};
	do
		if [ $j -gt $n ];then
			j=$n
		fi
		if [ $j -lt 50 ];then
			break;
		fi
	done
	if [ $j = 5000 ];then
		NODE_URL='http://download.bt.cn';
	else
		NODE_URL=${urls[$j]}
	fi
	
}

GetCpuStat(){
	time1=$(cat /proc/stat |grep 'cpu ')
	sleep 1
	time2=$(cat /proc/stat |grep 'cpu ')
	cpuTime1=$(echo ${time1}|awk '{print $2+$3+$4+$5+$6+$7+$8}')
	cpuTime2=$(echo ${time2}|awk '{print $2+$3+$4+$5+$6+$7+$8}')
	runTime=$((${cpuTime2}-${cpuTime1}))
	idelTime1=$(echo ${time1}|awk '{print $5}')
	idelTime2=$(echo ${time2}|awk '{print $5}')
	idelTime=$((${idelTime2}-${idelTime1}))
	useTime=$(((${runTime}-${idelTime})*3))
	[ ${useTime} -gt ${runTime} ] && cpuBusy="true"
	if [ "${cpuBusy}" == "true" ]; then
		cpuCore=$((${cpuInfo}/2))
	else
		cpuCore=$((${cpuInfo}-1))
	fi
}
GetPackManager(){
	if [ -f "/usr/bin/yum" ] && [ -f "/etc/yum.conf" ]; then
		PM="yum"
	elif [ -f "/usr/bin/apt-get" ] && [ -f "/usr/bin/dpkg" ]; then
		PM="apt-get"		
	fi
}
cpuInfo=$(getconf _NPROCESSORS_ONLN)
if [ "${cpuInfo}" -ge "4" ];then
	GetCpuStat
else
	cpuCore="1"
fi
GetPackManager
if [ ! $NODE_URL ];then
	echo '正在选择下载节点...';
	get_node_url
fi
